post workout dextrose?

[DIESELPWR]

im just curious how many of you guys take dextrose or similar post workout without taking insulin .. how many carbs do you ingest and how long do you wait after your workout and then how long do you wait to have your protein shake after that? me personally, i just started taking arginine akg pre workout with cellucor c4 with with a little of a nitric stack that includes l-arginine , ornithine akg, glutamine, creatine, beta alanine, citrulline malate and taurine... i workout and then take carbo max with around 80 grams of carbs mostly maltodextrin with another scoop of the nitric stack. this is taken immediately after i work out and then wait an hour to have my protein shake.. and im wondering if i would be better off with pure dextrose or waxy maize or whatever or if more people dont like dextrose and why.. im just curious of some different opinions.

[DSM4Life]

Call me weird, i drink a shake then eat a meal.

[Times Roman]

there is actually some very good clinical data that supports a ratio of 3 or 4 to 1 ratio of simple carbs to protein before/during and after workout. there is a 45 minute window where the body is going through a very energetic anabolic period, and if you infuse the protein, with the simple carbs, (remember, the simple carbs will spike your insulin levels naturally, and the insulin is very anabolic), then you will get a much better synergestic result than if simple carbs only or protein only.
I recently read a book on this subject, and I can get you the clinical studies data, or the book, if you like.
Let me know

[DIESELPWR]

thanks times.. definately let me know, im interested.. can always learn more..

[jimmyinkedup]

Know what i do...i spend all the money i saved not buying useless NO supps and glutamine and dextrose and shit like that and I use it to buy food and aas. Then with all the extra time I have since im not wasting it on useless pursuits like nutrient timing and anabolic windows- well I spend that time training and resting and ultimately growing... growing just as much as when I thought both of the above were important.

[DIESELPWR]

Know what i do...i spend all the money i saved not buying useless NO supps and glutamine and dextrose and shit like that and I use it to buy food and aas. Then with all the extra time I have since im not wasting it on useless pursuits like nutrient timing and anabolic windows- well I spend that time training and resting and ultimately growing... growing just as much as when I thought both of the above were important.

well i do think it is important.. i mean you have a brief window when your body is in need of nutrients. i mean i wont go and buy the no product per se but i do like arginine since it vasodialates your veins and shuttles the most amount of nutrients as quickly as possible and absorb the most of.. if it didnt work, and had nothing to do with timing, why would bodybuilders and such use insulin .. it may not be super important, but i do think it has its place.. and ive seen some pretty good gains from it.. i mean it could just be from working hard, but maybe it is placebo, but either way i like it

[bjpennnn]

i have karbolyn pre and post workout i ****en love the stuff.

[DIESELPWR]

karbolyn by sci-fit? i just looked it up. think its similar to the carbomax

[jimmyinkedup]

well i do think it is important.. i mean you have a brief window when your body is in need of nutrients. i mean i wont go and buy the no product per se but i do like arginine since it vasodialates your veins and shuttles the most amount of nutrients as quickly as possible and absorb the most of.. if it didnt work, and had nothing to do with timing, why would bodybuilders and such use insulin.. it may not be super important, but i do think it has its place.. and ive seen some pretty good gains from it.. i mean it could just be from working hard, but maybe it is placebo, but either way i like it

I have to apologize - after i read my post in your reply i realize i came across very arrogant - sorry about that. That being said I stand by everything I stated in my post (i just shouldnt have come across the way i did). There are a few flaws with your thinking that just dont translate to real world results. Some of the things u think the products do - they actually dont and some of the things you think should translate to more muscle simply dont. The only thing i do agree with is that it is placebo and if the money and effort is worth it for you to get placebo effect - then by all means go for it. Only the individual can decide what peace of mind placebo effect creates is monetarily worth (i am being serious).

[DIESELPWR]

I have to apologize - after i read my post in your reply i realize i came across very arrogant - sorry about that. That being said I stand by everything I stated in my post (i just shouldnt have come across the way i did). There are a few flaws with your thinking that just dont translate to real world results. Some of the things u think the products do - they actually dont and some of the things you think should translate to more muscle simply dont. The only thing i do agree with is that it is placebo and if the money and effort is worth it for you to get placebo effect - then by all means go for it. Only the individual can decide what peace of mind placebo effect creates is monetarily worth (i am being serious).

That's no problem.. Everyone is entitled to their own opinion

[Sgt. Hartman]

there is actually some very good clinical data that supports a ratio of 3 or 4 to 1 ratio of simple carbs to protein before/during and after workout. there is a 45 minute window where the body is going through a very energetic anabolic period, and if you infuse the protein, with the simple carbs, (remember, the simple carbs will spike your insulin levels naturally, and the insulin is very anabolic), then you will get a much better synergestic result than if simple carbs only or protein only.
I recently read a book on this subject, and I can get you the clinical studies data, or the book, if you like.
Let me know

Not trying to call you out or start an argument but the "anabolic window" myth has been debunked by dozens of recent studies and by the current top minds in exercise nutrition. The fact is that protein synthesis can last for over 24 hours after WO and the post WO meal is of no more importance than any other in that 24 hour period. Don't take my word for it though, look up what Alan Aragon, Will Brink, Dave Barr, or Lyle McDonald have studied and wrote about it.

Just my $.02, take it for what it's worth.

[baseline_9]

Know what i do...i spend all the money i saved not buying useless NO supps and glutamine and dextrose and shit like that and I use it to buy food and aas. Then with all the extra time I have since im not wasting it on useless pursuits like nutrient timing and anabolic windows- well I spend that time training and resting and ultimately growing... growing just as much as when I thought both of the above were important.

I love that answer...

Im no bullsh*t and the only sups I use are a basic Whey concentrate, creatine monohydrate and BCAA's

The supplement companies have brain washed the BBing world...

I know the store manager to one of the UK's largest supp suppliers, he saw me drinking a shake with whey and oats... He said ''Why are you drinking oats, your body needs dextrose'' and he genuinely believed that. I just cant be bothered to reply anymore.

Ive had '' You do realise your missing the window off opportunity if you dont have simple carbs'' my reply, ''can you please explain why that is the case, and if so could you please refer me to a single study showing that protein synthesis can be increased over a 24 hour period when simple vs complex carbs are consumed PWO''.... The general reply is something like ''well u know, they are quick and get into your muscles quickly''

[DanB]

I love that answer...

Im no bullsh*t and the only sups I use are a basic Whey concentrate, creatine monohydrate and BCAA's

The supplement companies have brain washed the BBing world...

I know the store manager to one of the UK's largest supp suppliers, he saw me drinking a shake with whey and oats... He said ''Why are you drinking oats, your body needs dextrose'' and he genuinely believed that. I just cant be bothered to reply anymore.

Ive had '' You do realise your missing the window off opportunity if you dont have simple carbs'' my reply, ''can you please explain why that is the case, and if so could you please refer me to a single study showing that protein synthesis can be increased over a 24 hour period when simple vs complex carbs are consumed PWO''.... The general reply is something like ''well u know, they are quick and get into your muscles quickly''

lmao love catching people out when they are parroting info they have no clue about, another good 1 is when they start going on about creatine ask them to explain how it works, alot of time people have no clue,some dont even know that its produced naturally just ''your muscles need it'' haha

[bjpennnn]

karbolyn by sci-fit? i just looked it up. think its similar to the carbomax

Professional supplements use to sell it by the owner passed away a few months ago and they stopped selling it think another company bought it off them or something. I highly highly recommend it, all the flavors taste great.

[Times Roman]

Not trying to call you out or start an argument but the "anabolic window" myth has been debunked by dozens of recent studies and by the current top minds in exercise nutrition. The fact is that protein synthesis can last for over 24 hours after WO and the post WO meal is of no more importance than any other in that 24 hour period. Don't take my word for it though, look up what Alan Aragon, Will Brink, Dave Barr, or Lyle McDonald have studied and wrote about it.

Just my $.02, take it for what it's worth.

I'm not a professor, just a bloke trying to make sense out of it all. The book i'm referring to is "Nutrient Timing" by John Ivy and Robert Portman. The bibliography contains all the clinical data, studies and research papers. It starts on page 190 and concludes on page 206.... 16 pages with maybe 12 or so references to outside the outside sources I just mentioned. So about 200 references. A very quick scan shows the most recent reference to be around 2003. I bring this up since you mention "recent" studies suggest.... How recent are you thinking? More recent than 2003? If so, this book could be out of date, since this book was published in 2004.

It seems contrary to common sense to suggest that the protein requirement is no greater post workout (think tissue damage due to stress, depletion of glycogen stores, tissue requirement at the cellular level for protein replenishment etc.) than it is 24 hours after workout?

Let me check out your reference in bold, and maybe I can learn something?

[l2elapse]

Not trying to call you out or start an argument but the "anabolic window" myth has been debunked by dozens of recent studies and by the current top minds in exercise nutrition. The fact is that protein synthesis can last for over 24 hours after WO and the post WO meal is of no more importance than any other in that 24 hour period. Don't take my word for it though, look up what Alan Aragon, Will Brink, Dave Barr, or Lyle McDonald have studied and wrote about it.

Just my $.02, take it for what it's worth.

Please post the studies...

[Times Roman]

here are some interesting links that seem to support my position:

from wiki (for starters):
http://en.wikipedia.org/wiki/Nutrient_timing

here's the book I was mentioning:
http://www.amazon.com/Nutrient-Timin.../dp/1591201411

here is another recommendations:
http://www.johnberardi.com/articles/...ent_timing.htm

here is from a sports training blog:
http://sportstrainingblog.com/sports...orts-nutrition

something from the University of Texas:
http://www.utexas.edu/features/archi...nutrition.html

something from the University of new mexico:
http://www.unm.edu/~lkravitz/Article...trientUNM.html

[Times Roman]

and a position statement from JISSN:
http://www.jissn.com/content/5/1/17
(so there you have it, I've stated a position and provided relevent, reliable data. I'm interested to hear the opposing data?

Review
International Society of Sports Nutrition position stand: Nutrient timing
Chad Kerksick1,2*, Travis Harvey3, Jeff Stout1, Bill Campbell4, Colin Wilborn5, Richard Kreider6, Doug Kalman7, Tim Ziegenfuss8, Hector Lopez9, Jamie Landis10, John L Ivy11 and Jose Antonio12

* Corresponding author: Chad Kerksick [email protected]

Author Affiliations
1 Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019, USA

2 Endocrinology and Diabetes Section, Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA

3 Center for Physical Development Excellence, Department of Physical Education, United States Military Academy, 727 Brewerton Road, West Point, NY 10996, USA

4 School of Physical Education & Exercise Science, University of South Florida, Tampa, FL 33620, USA

5 Exercise & Sport Science Department, University of Mary-Hardin Baylor, Belton, TX 76513, USA

6 Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA

7 Nutrition/Endocrinology Division, Miami Research Associates, Miami, FL 33143, USA

8 Division of Sports Nutrition and Exercise Science, The Center for Applied Health Sciences, Fairlawn, OH 44333, USA

9 Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA

10 Department of Biology, Lakeland Community College, Kirtland, OH 44094, USA

11 Department of Kinesiology & Health Education, University of Texas, Austin, TX 78712, USA

12 Farquhar College of Arts and Sciences, Nova Southeastern University, Fort Lauderdale, FL 33314, USA

For all author emails, please log on.
Journal of the International Society of Sports Nutrition 2008, 5:17 doi:10.1186/1550-2783-5-17



The electronic version of this article is the complete one and can be found online at: http://www.jissn.com/content/5/1/17


Received: 17 September 2008
Accepted: 3 October 2008
Published: 3 October 2008


© 2008 Kerksick et al; licensee BioMed Central Ltd.


This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract
Position Statement: The position of the Society regarding nutrient timing and the intake of carbohydrates, proteins, and fats in reference to healthy, exercising individuals is summarized by the following eight points: 1.) Maximal endogenous glycogen stores are best promoted by following a high-gly***ic, high-carbohydrate (CHO) diet (600 – 1000 grams CHO or ~8 – 10 g CHO/kg/d), and ingestion of free amino acids and protein (PRO) alone or in combination with CHO before resistance exercise can maximally stimulate protein synthesis. 2.) During exercise, CHO should be consumed at a rate of 30 – 60 grams of CHO/hour in a 6 – 8% CHO solution (8 – 16 fluid ounces) every 10 – 15 minutes. Adding PRO to create a CHO:PRO ratio of 3 – 4:1 may increase endurance performance and maximally promotes glycogen re-synthesis during acute and subsequent bouts of endurance exercise. 3.) Ingesting CHO alone or in combination with PRO during resistance exercise increases muscle glycogen, offsets muscle damage, and facilitates greater training adaptations after either acute or prolonged periods of supplementation with resistance training. 4.) Post-exercise (within 30 minutes) consumption of CHO at high dosages (8 – 10 g CHO/kg/day) have been shown to stimulate muscle glycogen re-synthesis, while adding PRO (0.2 g – 0.5 g PRO/kg/day) to CHO at a ratio of 3 – 4:1 (CHO: PRO) may further enhance glycogen re-synthesis. 5.) Post-exercise ingestion (immediately to 3 h post) of amino acids, primarily essential amino acids, has been shown to stimulate robust increases in muscle protein synthesis, while the addition of CHO may stimulate even greater levels of protein synthesis. Additionally, pre-exercise consumption of a CHO + PRO supplement may result in peak levels of protein synthesis. 6.) During consistent, prolonged resistance training, post-exercise consumption of varying doses of CHO + PRO supplements in varying dosages have been shown to stimulate improvements in strength and body composition when compared to control or placebo conditions. 7.) The addition of creatine (Cr) (0.1 g Cr/kg/day) to a CHO + PRO supplement may facilitate even greater adaptations to resistance training. 8.) Nutrient timing incorporates the use of methodical planning and eating of whole foods, nutrients extracted from food, and other sources. The timing of the energy intake and the ratio of certain ingested macronutrients are likely the attributes which allow for enhanced recovery and tissue repair following high-volume exercise, augmented muscle protein synthesis, and improved mood states when compared with unplanned or traditional strategies of nutrient intake.

Nutrient timing and exercise: a review of the literature
Introduction
Previous research has demonstrated that the timed ingestion of carbohydrate, protein, and fat may significantly affect the adaptive response to exercise. The overall concept of macronutrient ratio planning for the diets of athletes is not addressed directly within this position stand, as there is no one recommendation which would apply to all individuals. However, the ISSN refers the reader to the latest Institute of Medicine Guidelines for Macronutrient intake as a source of more general information [1]. The purpose of this collective position statement is to highlight, summarize, and assess the current scientific literature, and to make scientific recommendations surrounding the timed ingestion of carbohydrates (CHO), protein (PRO), and fat. The enclosed recommendations are suitable for researchers, practitioners, coaches and athletes who may use nutrient timing as a means to achieve optimum health and performance goals. This position stand is divided into three primary sections: pre-exercise, during exercise and post-exercise. Each section concludes with several bullet points that highlight the key findings from each of the areas.

Nutrient timing: pre-exercise
Nutritional considerations prior to exercise have traditionally examined the administration of CHO to maximize endogenous glycogen stores [2-6] and maintain serum glucose levels during endurance exercise [4,7]. More recently, studies have begun to provide data supporting the contention that pre-exercise ingestion of CHO, amino acids, PRO, and creatine (Cr) prior to resistance training are effective modalities for enhancing exercise training adaptations [8-12] and decreasing exercise associated muscle damage [12,13].

Pre-exercise ingestion of carbohydrate
Body stores of glycogen are limited [7,14], and will last a few hours at best during moderate to high intensity levels (65 – 85% VO2max) of exercise [15]. As glycogen levels diminish, exercise intensity, and work output decrease [14], and frequently muscle tissue breakdown and immunosuppression ensues [16,17]. Due to the well-established connection between negative body changes and the depletion of glycogen stores, the concept of CHO loading is likely the oldest form of all the nutrient timing practices. Daily ingestion of high-CHO meals (~65% CHO) is recommended to maintain muscle glycogen, while increased ingestion rates are employed (~70% CHO) in the 5 – 7 days leading up to competition as a means of maximizing muscle and liver glycogen stores and in order to sustain blood glucose during exercise [2,4,5]. Traditional CHO loading studies utilized a glycogen depletion phase typically lasting 3 – 6 days prior to increasing CHO intake [2-5,18]. Maximal levels of glycogen storage, however, may be achieved after just 1 – 3 days of consuming a high-CHO diet while minimizing physical activity [2,4]. For example, Kavouras and colleagues instructed twelve endurance-trained cyclists to perform a 45 min bicycle ride at 82% VO2 peak after six days of following either an isoenergetic high-CHO (600 g) or low-CHO (100 g) diet. Prior to exercise, muscle glycogen levels were significantly higher (p < 0.05) in the high-CHO condition (104.5 ± 9.4 mmol/kg/wet wt) when compared to the low-CHO condition (72.2 ± 5.6 mmol/kg/wet wt). Serum glucose levels increased during exercise in the high-CHO condition with no changes evident in the low-CHO condition. Finally, post-exercise glucose levels were also significantly greater for the high-CHO condition when compared to the low-CHO condition, suggesting that individuals subjected to the high-CHO condition were better able to sustain blood glucose levels. No changes were noted for serum free fatty acids, triglycerides or insulin (p > 0.05) [4]. Another study by Bussau et al. [2] found that eating a high-gly***ic CHO (10 g/kg/day) diet for as little as one day could significantly increase muscle glycogen levels. In that particular study, muscle glycogen levels increased from baseline levels of 95 ± 5 mmol/kg/wet wt to 180 ± 15 mmol/kg/wet wt after one day, and remained at those levels for three subsequent days.

Research involving the ingestion of single high CHO feedings has also demonstrated the promotion of higher levels of muscle glycogen and an improvement of blood glucose maintenance (eugly***ia), though changes in performance have been equivocal [14,19-22]. In a study completed by Coyle et al. [14], cyclists were instructed to ingest a high CHO meal four hours prior to completing a prolonged (105 min) exercise bout at 70% VO2max. The single meal increased muscle glycogen by 42%, which resulted in higher levels of CHO oxidation and utilization of muscle glycogen. In contrast, Febbraio et al. [21] reported that ingestion of a high-gly***ic meal 45 min before 135 min of cycling exercise was not responsible for changes in muscle glycogen utilization or performance when compared to a low-gly***ic meal or water. A follow-up study in 2000 found no changes in performance after 150 min of cycling at 70% VO2max when either a high-gly***ic or low-gly***ic meal was consumed 30 min before exercise [20]. Earnest et al. compared the effects of the pre-exercise ingestion of honey (low-gly***ic), dextrose (high-gly***ic) and a placebo over a 64-kilometer time trial in a crossover fashion. While CHO ingestion was thought to be responsible for greater power output over the last 16% of the time trials, no difference in performance was noted between the high and low-gly***ic groups [19]. In general, research involving CHO ingestion within an hour prior to exercise demonstrates equivocal results regarding changes in performance, but studies have routinely shown the ability of CHO ingestion to maximize glycogen utilization and promote CHO oxidation. Hawley and Burke [22] summarized several studies that administered some form of CHO within one hour prior to exercise: one study reported a decrease in performance [23], three studies reported an increase in performance [24-26] and five studies reported no effect [21,27-30] (Additional File 1).

Additional file 1. Table 1 – Summary table of pre-exercise nutrition studies (Adapted from Hawley and Burke [22]).

Format: DOC Size: 63KB Download file

[Times Roman]

This file can be viewed with: Microsoft Word Viewer
Pre-exercise ingestion of amino acids and protein
Researchers have begun to explore the potential of ingesting PRO and/or amino acids, either alone or in combination with CHO, in order to enhance training adaptations to resistance exercise. An study investigating this potential relationship compared the ingestion of a CHO + PRO supplement (35 grams of CHO with 6 grams of essential amino acids) consumed either immediately before, or immediately after, a single bout of resistance exercise at 80% one-repetition maximum (1 RM) [9]. The authors concluded that the effect on the net PRO status (breakdown vs. synthesis) was greater when the supplement was ingested before exercise. They speculated that the increased serum amino acid levels present when tissue blood flow levels were significantly increased, likely led to an increase in PRO synthesis [9]. The same authors subsequently compared the changes in PRO metabolism following the ingestion of 20 grams of whey PRO both immediately before, or immediately after, a single resistance exercise bout at 80% 1 RM [31]. In this case the authors concluded that a pro-anabolic response was found when the whey PRO was ingested both before and after resistance exercise, but no differences were found between the two administration times [31]. Findings from these studies suggest that ingestion of amino acids and CHO, or whey PRO, before resistance exercise can maximally stimulate PRO synthesis after completion of the exercise bout [9,31].

Many studies have explored the use of pre-exercise PRO and CHO ingestion in preventing acute exercise-induced muscle damage [13], as well as the damage that may occur during prolonged periods of regular resistance training [8,10-12,32]. A recently published study evaluated 27 adult male participants who consumed either a placebo (a non-caloric sweetener), or a CHO + PRO solution (75 g CHO + 23 g PRO) 15 min before, or 15 min after completing a potentially muscle-damaging bout of eccentric contractions. Although the authors reported that the level of the muscle damage marker creatine kinase had increased and maximal force production of the muscle was reduced, the administration or timing of the nutrients did not appear to alter these markers of muscle damage [13]. In another study, participants ingested either a multi-nutrient (CHO + PRO + Fat) supplement or an isoenergetic maltodextrin placebo for seven days before reporting to the laboratory for two consecutive days of resistance training [12]. On both exercise days, the supplement was ingested 30 min prior to beginning the exercise bout. The multi-nutrient supplementation significantly improved vertical jump power and number of repetitions performed at 80% 1 RM. Additionally, multi-nutrient supplementation significantly increased serum levels of both growth hormone and free and total testosterone during and after the exercise bouts [12]. These latter findings suggest that pre-exercise ingestion may also create a favorable anabolic hormone environment. In another study involving unilateral resistance training, pre-exercise supplementation of whey PRO and leucine resulted in greater increases in maximal strength [11]. Thirty-three male participants completed six weeks of unilateral lower body resistance training while assigned to either a resistance training only (control) group, a resistance training + 26 g CHO (placebo) group, or a resistance training + 20 g whey PRO + 6 g leucine group. The authors concluded that pre-exercise supplementation of whey PRO + leucine promoted significantly greater increases in strength (+ 30.3%) when compared to the energy-matched placebo (+ 22.4%) and control (+ 3.6%) groups [11]. Two additional studies also compared the ingestion of CHO + PRO before and after eight and 12 weeks of resistance training, respectively. One study compared the pre-exercise and post-exercise ingestion of 1.2 g/kg whey PRO + 0.3 g/kg CHO, 1.2 g/kg soy PRO + 0.3 g/kg CHO, or placebo during eight weeks of resistance training. The authors found that PRO supplementation significantly increased strength and lean mass when compared to placebo, but no differences were found between the two forms of PRO [32]. The second study had participants perform heavy resistance exercise (3 sets of 6 – 8 repetitions at 85 – 90% 1 RM) 4 days per week for 10 weeks [10]. Participants were assigned to ingest either 20 g PRO (14 g whey and casein PRO + 6 g free amino acids), or 20 g CHO before and after each exercise bout for a total of 40 g/d of PRO or 40 g/d CHO. Individuals consuming the protein supplement experienced greater increases in body mass, fat-free mass, strength, serum levels of IGF-1, and intramuscular levels of IGF-1 mRNA, myosin heavy chain I and IIa expression, and myofibrillar protein content [10]. Collectively, the last two studies mentioned provide additional support for the concept that ingesting PRO before and after exercise can promote a greater training adaptation than consuming only an isoenergetic CHO placebo [10,32].

A 2006 study by Cribb and Hayes [8] used two different feeding strategies to determine the impact of nutrient timing, in regards to an exercise bout, for changes in strength, muscle hypertrophy and body composition. Participants were instructed to ingest equal quantities of a supplement containing PRO, Cr and CHO at a dose of 1 g/kg either immediately before and immediately after each workout, or in the morning and evening of each workout day. Significantly greater increases in lean body mass, 1 RM strength, type II muscle fiber cross-sectional area, and higher muscle Cr and glycogen levels were found when the supplements were consumed immediately before and after workouts [8]. In summary, ingestion of amino acids or PRO, either alone or in combination with CHO, in close temporal proximity to a bout of resistance exercise, appears to significantly increase muscle PRO synthesis [9,31]. Furthermore, adopting this strategy during a resistance training program results in greater increases in 1 RM strength and a leaner body composition [8,10-12,32].

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Summary of pre-exercise nutrient ingestion findings
• Glycogen stores are limited and depend largely on the nutritional status and the intensity and training level of the athlete [7,14]. Endogenous glycogen stores during moderate to high intensity levels (65 – 85% VO2max) of exercise may only last from 90 min to 3 h [15].

• Exercise intensity, pace and work output decrease as glycogen levels diminish [14]. Depletion of glycogen is associated with increased levels of muscle tissue breakdown and suppression of the immune system [16,17].

• Maximal endogenous glycogen stores are best promoted by following a high-gly***ic, high-CHO diet (600 – 1000 grams or ~8 – 10 g/kg/d) [2,3,15].

• The optimal CHO and PRO content of a pre-exercise meal is dependent upon a number of factors including exercise duration and fitness level, but general guidelines recommend ingestion of 1 – 2 grams CHO/kg and 0.15 – 0.25 grams PRO/kg 3 – 4 hours before competition [15].

• Pre-exercise ingestion of essential amino acids or PRO alone increases muscle protein synthesis. In addition, ingesting PRO + CHO pre-exercise has been shown to produce significantly greater levels of muscle protein synthesis [9,31].

• Regular ingestion of various PRO sources in conjunction with CHO stimulates greater increases in strength and favorably impacts body composition when compared to CHO alone [8,10,11].

Nutrient timing: during exercise
Much like the consideration of pre-exercise nutrient supplementation, a majority of the literature which has examined the impact of nutrient administration during exercise has focused on aerobic exercise [33-36], with a lesser emphasis on nutrient administration during resistance exercise [37-41].

Glucose administration during endurance exercise
The initial research which dealt with nutrient administration during exercise scrutinized the optimal delivery of CHO in an effort to sustain blood glucose. For example, Australian researchers had eight highly-trained cyclists complete two trials at 70% VO2max until the point of volitional fatigue [42]. Before exercise, and every 15 min throughout, participants were either given a placebo or an 8% CHO solution to ingest. Ingestion of the CHO solution was associated with a 30% increase in time to reach volitional exhaustion, or a 47 min longer period of cycling when compared to placebo [42]. Widrick and colleagues [35] had participants complete 70 km of self-paced time trials under four different conditions: 1.) high glycogen (180.2 ± 9.7 mmol/kg/wet wt) + CHO beverage; 2.) high glycogen (170.2 ± 10.4 mmol/kg/wet wt) + Non-CHO beverage; 3.) low glycogen (99.8 ± 6.0 mmol/kg/wet wt) + CHO beverage; 4.) low glycogen (109.7 ± 5.3 mmol/kg/wet wt) + non-CHO beverage [35]. The CHO drink was ingested at the onset of exercise and every 10 km after, providing 116 ± 6 g CHO/trial. CHO administration maintained blood glucose, while blood glucose declined significantly under the non-CHO conditions. Over the final 14% of the time trial (9.8 km), power output and pace were significantly less in the low glycogen + non-CHO condition when compared to the other three conditions. Results from this study suggest exogenous CHO delivery during training is not as important if baseline glycogen levels are high, and if glycogen levels are low, CHO ingestion during endurance exercise will likely improve performance. In a similar investigation, nine trained athletes consumed both a CHO and a non-CHO control solution while completing a 90 min bout of high-intensity intermittent running [34]. The CHO solution was 6.9% CHO and was first provided immediately prior to exercise, and subsequently every 15 min after the exercise bout started. When CHO was ingested the participants were able to run significantly longer when compared to the control condition, providing additional evidence that CHO availability may be important for continued exercise performance [34]. An additional study highlighting the importance of CHO delivery during endurance exercise was completed by Febrraio et al. in 2000 [33]. This study, like several in this investigative field, utilized trained cyclists as participants. The cyclists undertook a 120 min bout of cycling at 63% of their peak power under four conditions: 1) placebo before and during exercise [PP]; 2) placebo 30 min before + CHO (2 g/kg in a 6.4% CHO solution) during exercise [PC]; 3) CHO (2 g/kg in a 25.7% CHO solution) before exercise + placebo during exercise [CP]; or 4) CHO (2 g/kg in a 25.7% CHO solution) before exercise + CHO (2 g/kg in a 6.4% CHO solution) [CC] during exercise. Blood glucose appearance and disappearance, and time trial performance was greater in the CC and PC trials when compared to the PP condition. The authors concluded that pre-exercise ingestion of CHO improves performance only when CHO ingestion is maintained throughout exercise, and ingestion of CHO during 120 min of cycling improves subsequent time trial performance [33]. Similarly, a study by Fielding et al. reported that more frequent intake of CHO (10.75 g CHO in 200 ml water; ~5% CHO solution) at 30 min intervals versus large feedings (86 gram doses) at 60 min intervals over a four hour bike ride equally sustained blood glucose and insulin activity, but the shorter interval of intake facilitated a significantly longer sprint ride to exhaustion at the end of exercise [43]. These findings conflicted with those of Burke et al. [44] who reported no impact of a gly***ic meal consumed prior to exercise on subsequent time trial performance. Lastly, a 2007 study investigated the ability of a consumed CHO-gel preparation to maintain blood glucose levels and enhance performance during a high-intensity intermittent run in soccer players [45]. As with previous studies that have used CHO solutions, the CHO-gel promoted higher levels of blood glucose and facilitated improved performance in the intermittent bout of running when compared to the placebo [45]. In summary, the weight of evidence suggests that the ingestion of CHO during endurance type exercise is a well-established strategy to sustain blood glucose levels, spare glycogen [6], and potentially promote greater levels of performance. The interested reader is encouraged to consult the following reviews [15,46-49].

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Mixing carbohydrates to increase carbohydrate oxidation
A fairly novel area of research has examined the impact of mixing various forms of CHO in an effort to promote greater levels of CHO oxidation during prolonged exercise. It is well accepted that peak rates of CHO oxidation are commonly around 1 gram of CHO per minute or 60 grams per hour [15,48]. An increase in exogenous CHO availability, and subsequent oxidation, will result in improved maintenance of blood glucose and less reliance on liver and muscle glycogen stores. For example, recent studies have illustrated a 21% increase in CHO oxidation to 1.2 g CHO/min after ingesting a mixture of glucose and sucrose [50]; while a combination of maltodextrin and fructose was responsible for a 40% increase in peak CHO oxidation levels to approximately 1.5 g/min over maltodextrin alone during prolonged cycling at 60 – 65% VO2max [51]. Indeed, findings from this research team have regularly reported enhanced CHO oxidation rates, from 1.2 – 1.75 grams of CHO per minute [50,52-55]. Most recently, a 2008 paper by this same research group reported an 8% increase in time-trial performance after a 120 min ride at 55% maximum watts when ingesting a combination of glucose and fructose during exercise [56]. It should be noted that fructose is not as often used as a CHO supplement due to the potential for gastrointestinal upset.

Adding protein or amino acids to carbohydrate during endurance exercise
The addition of PRO to CHO during exercise has also been investigated as a means to improve performance and facilitate recovery. In one study, participants completed 3 h of cycling @ 45 – 75% VO2max, followed by a time to exhaustion trial at 85% VO2max. During each session, participants consumed either a placebo, a 7.75% CHO solution, or a 7.75% CHO/1.94% PRO solution. While the CHO only group increased time to exhaustion (19.7 ± 4.6 min) versus the placebo (12.7 ± 3.1 min), the addition of PRO resulted in even greater performance (26.9 ± 4.5 min) [57]. A study by Saunders et al. examined the impact of a CHO + PRO combination for its ability to improve performance and minimize muscle damage [58]. Cyclists exercised to exhaustion on two different occasions separated by 12 – 15 h. During exercise, all participants ingested a 7.3% CHO solution, or a 7.3% CHO/1.8% PRO solution, every 15 min during exercise, and after exercise. CHO intake levels were the same for each group, although the total caloric intake was different (due to the energy supplied by the added PRO). A 29% increase in performance occurred after the first bout of exercise, and a 40% increase in performance after the 2nd bout of exercise for the CHO + PRO group when compared to the CHO group. Additionally, post-exercise levels of muscle damage markers were 83% lower, suggesting the CHO + PRO supplement helped to attenuate the muscle damage associated with prolonged and exhaustive exercise [58]. A 2007 study by the same research group used a similar study design with a CHO + PRO gel during exercise and found that the gel again improved performance by 13% over a placebo [59]. Furthermore, a 2004 study recruited ultra-endurance athletes to compare the impact of CHO and CHO + PRO on changes in protein turnover and recovery after 6 h of endurance exercise [36]. PRO balance was negative during the CHO condition, but these findings were partially reversed (protein balance was still negative, but to a lesser degree) when PRO was added to the supplement. The authors concluded that combined ingestion of PRO and CHO improves net PRO balance at rest, as well as during exercise and post-exercise recovery [36].

Addition of protein, amino acids and carbohydrate during resistance exercise
Delivering nutrients during single bouts of resistance exercise has been used to determine their impact on changes in muscle glycogen [40], mitigation of muscle damage [13,37], and promotion of an anabolic response [38,39,41]. Over the course of an estimated 40 min resistance training workout using the lower body, 1.0 g CHO/kg was provided before exercise and 0.5 g CHO/kg was given every 10 min throughout the workout to determine changes in muscle glycogen [40]. Decrements in muscle glycogen were offset by 49% when CHO was provided before and during the resistance exercise. The authors concluded that CHO supplementation before and during resistance exercise can maintain muscle glycogen stores and enhance the benefits of training [40].

Nutrient feedings during exercise have also been researched for their ability to offset muscle damage after intense resistance training [37]. Baty and colleagues[37] had 34 males complete an acute bout of heavy resistance training (3 sets × 8 reps @ 90% 1 RM) while consuming either a CHO solution (6.2% CHO) or a CHO + PRO solution (6.2% CHO + 1.5% PRO) before, during, and after the exercise bout. While no changes in performance were noted, the authors did report significantly greater levels of the anabolic hormone insulin and significantly lower levels of the catabolic hormone cortisol in the participants who ingested the CHO + PRO solution when compared to the CHO solution at several points after exercise. Furthermore, serum levels of myoglobin were lower during and immediately following exercise and creatine kinase was significantly lower 24 hours post exercise when the CHO + PRO supplement was provided. The authors concluded that the CHO + PRO solution had no impact over performance, but did lower serum markers of muscle damage during and several hours after completion of resistance training [37].

Two studies explored the changes in protein degradation and increases in serum levels of cortisol with ingestion of a CHO + PRO solution (6% CHO + 6% essential amino acids) during a single bout of resistance training exercise [38,39]. During both studies, 32 participants completed a 60 min bout of resistance training while consuming either a 6% CHO solution, a 6% CHO + 6 g essential amino acid (EAA) solution, or a placebo beverage. Serum levels of cortisol increased 105% in the placebo group, while changes in the CHO and CHO + EAA groups were 11% and 7%, respectively. Further, urinary levels of 3-methyl-histidine (a marker of muscle protein breakdown) were reduced by 27% in the CHO + EAA group, while these values increased by 56% in the placebo group [38,39]. The authors concluded that the suppression of PRO breakdown and cortisol levels may help to promote accretion of muscle PRO with prolonged periods of resistance training and supplementation. Their final study examined the influence of a 12 week resistance training program in combination with CHO and EAA supplementation. In conjunction with the two previous studies, a 6% CHO solution, 6% CHO + 6 g EAA solution, or a placebo was consumed during resistance exercise. Serum insulin and cortisol, urinary markers of PRO breakdown, and muscle cross-sectional area were measured [41]. CHO + PRO ingestion corresponded with a 26% decrease in markers of PRO breakdown, while the placebo group increased PRO breakdown by 52%. Furthermore, muscle cross-sectional area of the type I, IIa and IIb fibers were increased with the CHO + PRO group, which displayed the greatest gains relative to placebo. The authors concluded that CHO + PRO supplementation with prolonged resistance training enhances muscle anabolism when compared to either CHO alone, or a placebo, by maximizing the anabolic response and attenuating the catabolic response [41]. Similarly, a 2008 study by Beelen et al. [60] had participants ingest a bolus of CHO + PRO at a dose of 0.15 g/kg body wt before initiating and at 15 min intervals during a two-hour bout of resistance training. PRO + CHO lowered the rate of PRO breakdown by 8.4 ± 3.6% and increased fractional PRO synthesis by 49 ± 22%, resulting in a 5-fold increase in PRO balance. Overall, the research supports the conclusion that the intake of nutrients such as CHO alone, or a combination of CHO + PRO, during resistance training may help promote greater levels of muscle glycogen, increase muscle cross-sectional area, and decrease PRO breakdown [38-41].

Summary of during exercise nutrient findings
• CHO availability during exercise and muscle glycogen levels are major determinants of endurance performance. CHO administration becomes even more important when muscle glycogen levels are low at the onset of exercise [35,42].

• As exercise duration increases beyond 60 min, exogenous sources of CHO become important to maintain blood glucose and muscle glycogen stores. This CHO source should supply 30 – 60 grams of CHO per hour and can typically be delivered by drinking 1 – 2 cups of a 6 – 8% CHO solution (8 – 16 fluid ounces) every 10 – 15 minutes [49].

• Mixing different forms of CHO has been shown to increase muscle CHO oxidation from 1.0 g CHO/min to levels ranging from 1.2 g – 1.75 g CHO/min [50,52-54]; an effect which is associated with an improvement in time trial performance [56].

• Glucose, fructose, sucrose and maltodextrin can be used in combination, but large amounts of fructose are not recommended due to the greater likelihood of gastrointestinal problems.

• The addition of PRO to CHO at a ratio of 3 – 4:1 (CHO: PRO) has been shown to increase endurance performance during both acute exercise and subsequent bouts of endurance exercise [57,58].

• Ingesting CHO alone, or in combination with PRO, during resistance exercise increases muscle glycogen stores [40], offsets muscle damage [37], and facilitates greater training adaptations after acute [38,39] and prolonged periods of resistance training [41].

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Nutrient timing: post-exercise
Many nutritional interventions have been considered to enhance recovery from exercise. The body of published research supports the practice of ingesting nutrients to enhance performance for both endurance and resistance training athletes. There is also sound evidence which supports the value of post-exercise nutritional supplementation as a means of improving the recovery of intramuscular glycogen, providing a positive stimulation for acute changes in amino acid kinetics and improvement of the net PRO balance, as well as enhancing the overall adaptation to resistance training.

Maximization of muscle glycogen re-synthesis
Athletes who ingest 1.5 g CHO/kg body wt. within 30 minutes after exercise have been shown to experience a greater rate of muscle glycogen re-synthesis than when supplementation is delayed by two hours, largely due to a greater sensitivity of muscle to insulin [61]. Additionally, both solid and liquid forms of CHO promote similar levels of glycogen re-synthesis [15,62,63]. Moreover, different forms of CHO have different effects on insulin levels, with fructose ingestion being associated with lower levels of glycogen re-synthesis than other forms of simple carbohydrates [64]. It has been demonstrated that delaying CHO ingestion by as little as two hours can reduce the rate of muscle glycogen re-synthesis by 50% [61]. If an athlete is glycogen-depleted after exercise, a CHO intake of 0.6 – 1.0 g CHO/kg/h during the first 30 minutes, and again every two hours for 4 – 6 hours, can adequately replace glycogen stores [65,66]. Similarly, maximal glycogen re-synthesis rates have been achieved when 1.2 g CHO/kg/h is consumed every 15 – 30 minutes [65,67]. Consequently, frequent feedings of CHO in high amounts over the 4 – 6 hours following exercise is recommended to ensure recovery of muscle and liver glycogen [15,49]. Additional studies have also reported that maximal glycogen levels can be restored within 24 h if optimal levels of CHO are available (8 g CHO/kg/day), and the degree of glycogen depletion is not too severe [62]. A CHO intake of 9 – 10 g CHO/kg/day is suggested for athletes who are completing intense exercise bouts on consecutive days [68].

Several studies have suggested that adding PRO to CHO supplementation after exercise may help to promote greater recovery of muscle glycogen and attenuate muscle damage. Ivy and colleagues [69] instructed cyclists to complete a 2.5 h bout of intense cycling before ingesting either a CHO + PRO + Fat (80 g CHO, 28 g PRO, 6 g Fat), low CHO (80 g CHO, 6 g fat), or a high CHO (108 g CHO, 6 g fat) supplement immediately after exercise, and 2 h post-exercise, to determine if the CHO + PRO + Fat combination promoted greater restoration of muscle glycogen. While glycogen replenishment did not differ between the two CHO conditions (low CHO [70.0 ± 4.0 mmol/kg/wet wt] and high CHO [75.5 ± 2.8 mmol/kg/wet wt]), muscle glycogen levels were significantly greater (p < 0.05) in the CHO + PRO + Fat treatment (88.8 ± 4.4 mmol/kg/wet wt). The authors concluded that a CHO + PRO + Fat supplement may be more effective because of its provocation of a more pronounced insulin response [66,69,70]. Similarly, studies by Berardi and Tarnopolsky [71,72] utilized cyclists for the completion of exercise bouts of 60 – 90 min on separate occasions before ingesting CHO + PRO or CHO alone. Both authors concluded that ingestion of either CHO preparation resulted in greater restoration of muscle glycogen when compared to a placebo. Berardi [71], however, reported even greater glycogen levels when the CHO + PRO combination was consumed post-exercise. Furthermore, the availability of essential amino acids (EAA) following exercise, especially the branched-chain amino acids, have been reported to influence recovery by optimizing PRO re-synthesis as well as glycogen re-synthesis rates after exercise [61,69,70,72-74]. As these studies suggest, the ingestion of CHO (1 – 1.5 g CHO/kg/day) within 30 minutes following the termination of an exercise bout promotes restoration of muscle glycogen, while the addition of PRO may have additional benefits in enhancing both muscle PRO and glycogen re-synthesis.

Acute changes in amino acid kinetics and protein balance
A single bout of resistance training modestly stimulates PRO synthesis, but also further stimulates PRO breakdown resulting in an overall negative PRO balance after exercise [75,76]; an effect which shifts PRO balance more towards neutral as training status progresses [76]. Infusion or ingestion of amino acids increases amino acid concentrations at rest or after resistance exercise [77]. In addition, providing CHO in combination with amino acids immediately before or after exercise may further increase amino acid availability and post-exercise PRO synthesis [73,78]. Consequently, increasing the concentration and availability of amino acids in the blood is an important consideration when attempting to promote increases in lean tissue and improve body composition with resistance training [77,79].

Ingestion of a large dose of CHO (100 g) alone and within 1 h after resistance exercise causes marginal improvements in overall PRO synthesis while maintaining a negative net PRO balance [78]. While no studies have found CHO to be detrimental, it is not the ideal nutrient (in isolation) to consume after resistance exercise. Its inclusion, however, is an important consideration regarding stimulation of glycogen re-synthesis and enhanced palatability [69,72]. The EAAs, however, in dosages ranging from 6 – 40 grams have routinely been shown to play a primary role in promoting muscle PRO synthesis [74,80], though adding CHO to them may enhance this effect [9,81].

Regarding post-exercise timing, ingestion of amino acids after resistance exercise has been shown at many different time points to stimulate increases in muscle PRO synthesis, cause minimal changes in PRO breakdown and increase overall PRO balance [74,75,80]. Unfortunately, the optimal time point for supplementation has not yet been demonstrated. Similar changes have been found in studies that have administered amino acids alone, or with CHO, immediately, 1 h, 2 h and 3 h after exercise [9,74,79,81]. Levenhagen et al. [82] found that after ingesting 10 g PRO + 8 g CHO + 3 g Fat either immediately or 3 h after 60 min of moderate-intensity exercise, leg muscle glucose uptake and whole body glucose utilization were elevated threefold and 44%, respectively. Leg muscle and whole-body PRO synthesis was increased threefold and 12%, respectively. Furthermore, Tipton and colleagues [9] supplemented participants with 35 g sucrose + 6 g EAAs immediately before, and immediately after, a single bout of resistance exercise. They reported significantly greater levels of PRO synthesis when the nutrients were ingested immediately before the exercise bout.

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In summary, the optimal dosage and ratio of EAAs and CHO necessary to optimize protein balance is not currently known. Studies using similar techniques to measure protein kinetics during resistance exercise have used 6 g EAA only, 6 g EAA + 6 g non-essential amino acids, 12 g EAA only, 17.5 g whey PRO, 20 g casein PRO, 20 g whey PRO, 40 g mixed amino acid, and 40 g EAA only; all have noted similar increases in PRO synthesis and PRO balance [9,73,77]. While the ratio of CHO to PRO requires additional investigation, a often utilized practical approach is to consume a supplement containing CHO + PRO in a 3:1 or 4:1 ratio within 30 minutes following exercise, which translates to 1.2 – 1.5 g/kg of simple CHO (e.g., dextrose, sucrose) with 0.3 – 0.5 g/kg of a quality PRO containing EAA [73,74,83]. A summary of relevant findings is provided in Table 2 (Additional File 2).

Additional file 2. Table 2 – Summary table of studies involving protein metabolism and nutrient timing after exercise.

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Post-exercise supplementation for promotion of training adaptations
In an attempt to stimulate greater adaptations associated with resistance training researchers have investigated the impact of administering varying combinations of CHO and PRO after (1 – 3 h post-exercise) each exercise bout over the course of training [8,10,32,84-91]. The collective findings of these studies support the rationale for post-exercise administration of CHO and PRO to facilitate greater improvements in strength and body composition. Additionally, PRO source may be an important consideration as studies have suggested that whey PRO may exhibit a faster kinetic digestive pattern when compared to casein PRO [92,93]. Furthermore, this faster kinetic pattern for whey PRO is responsible for greater increases in PRO synthesis upon ingestion, with little to no impact over PRO breakdown. Casein PRO, on the other hand, releases its amino acids at a slower rate from the gut. This kinetic pattern results in little control over PRO synthesis, but a powerful attenuation of PRO breakdown. When both of these milk PRO sources are compared using area under the curve analysis, results suggest that casein may be responsible for a greater overall improvement in PRO balance when compared to whey [92,93]. A summary of these studies is provided below in table 3 (Additional File 3), but the universal findings of these studies suggest that adding some combination of CHO (50 – 75 g) to a PRO source (20 – 75 g) while completing heavy resistance training facilitates an increase in the development of lean mass and overall improvements in body fat %.

Additional file 3. Table 3 – Summary table of studies involving post-exercise nutrition administration and resistance training.

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Adding creatine to carbohydrate and protein
In addition to providing a combination of CHO + PRO after regular resistance training, researchers have also examined the impact of adding creatine monohydrate (Cr) in an attempt to facilitate greater training adaptations [84,85,88,90]. Cr is a popular dietary supplement that has been heavily researched for its ability to increase performance and facilitate positive training adaptations [94,95]. For example, Tarnopolsky et al. [90] had previously untrained male participants undergo resistance training for eight weeks while ingesting, in a double-blind fashion, either a Cr (10 g) + CHO (75 g) or PRO (10 g) + CHO (75 g) combination 30 min after exercise. Following assessment of changes in strength and muscle mass, the Cr + CHO group gained significantly more body mass (5.4% increase from baseline) when compared to the PRO + CHO group (2.4% increase). Changes in fat-free mass, muscle fiber area, 1 RM, and isokinetic strength improved in both groups, but were not different among groups. Another study had participants resistance train for 11 weeks while consuming daily one of the following: 1) 0.1 g Cr/kg/day + 1.5 g CHO/kg/day, 2) 0.1 g Cr/kg/day + 1.5 g whey PRO/kg/day), 3) 1.5 g/kg/d whey PRO only or 4) 1.5 g CHO/kg/day only. Supplementation in the first three groups resulted in greater increases in 1 RM strength and muscle hypertrophy when compared to CHO only, but no differences were found among the groups ingesting Cr in conjunction with either CHO or PRO [85].

In contrast, two published studies have suggested that the addition of Cr may be responsible for greater increases in muscle hypertrophy. The first study had participants complete heavy resistance training for 10 weeks while ingesting one of the following isoenergetic groups: 1) 1.5 g/kg/day of PRO only, 2) 0.75 g PRO/kg/day + 0.75 g CHO/kg/day, or 3) 0.1 g Cr/kg/day + 0.75 g PRO/kg/day + 0.75 g CHO/kg/day. Changes in strength and muscle hypertrophy were found to be greater in the Cr + CHO + PRO group when compared to the CHO + PRO group [84]. Similarly, Kerksick and colleagues [88] had participants complete 12 weeks of resistance training while ingesting a blend of whey and casein PRO, with or without Cr. While all groups saw increases in strength and muscle mass, those groups ingesting Cr with the PRO blend experienced greater gains in body mass and fat-free mass. Though these findings are somewhat mixed, the available data does provide support that adding Cr to a post-exercise regimen of CHO and PRO may help to facilitate greater improvements in body composition during resistance training [84,85,88,90].

Summary of post-exercise nutrient ingestion findings
• Post-exercise (within 30 minutes) consumption of CHO at high dosages (8 – 10 g CHO/kg/day) has been shown to stimulate muscle glycogen re-synthesis [15,65].

• Adding PRO (0.2 g – 0.5 g PRO/kg/day) to CHO at a ratio of approximately 3: 1 (CHO: PRO) has been shown to stimulate glycogen re-synthesis to a greater extent [69].

• Post-exercise ingestion (immediately after through 3 hours post) of amino acids, primarily EAAs, have been shown to stimulate robust increases in muscle PRO synthesis [73,74,83]. The addition of CHO may increase PRO synthesis even more, while pre-exercise consumption may result in the best response of all [9].

• During prolonged resistance training, post-exercise consumption of CHO + PRO supplements in varying amounts have been shown to stimulate improvements in strength and body composition when compared to control, placebo, or CHO-only conditions [10,87,90].

• The addition of Cr (0.1 g Cr/kg/day) to a CHO + PRO supplement may facilitate even greater adaptations to resistance training [84,88].

Conclusion
The scientific literature associated with nutrient timing is an extremely popular, and thus ever-changing, area of research. Upon reviewing the available literature, the following conclusions can be drawn at this point in time:

• Prolonged exercise (> 60 – 90 min) of moderate to high intensity exercise will deplete the internal stores of energy, and prudent timing of nutrient delivery can help offset these changes.

• During intense exercise, regular consumption (10 – 15 fl oz.) of CHO/electrolyte solution delivering 6 – 8% CHO (6 – 8 g CHO/100 ml fluid) should be consumed every 15 – 20 min to sustain blood glucose levels.

• Glucose, fructose, sucrose and other high-gly***ic CHO sources are easily digested, but fructose consumption should be minimized as it is absorbed at a slower rate and increases the likelihood of gastrointestinal problems.

• The addition of PRO (0.15 – 0.25 g PRO/kg/day) to CHO at all time points, especially post-exercise, is well tolerated and may promote greater restoration of muscle glycogen.

• Ingestion of 6 – 20 grams of EAAs and 30 – 40 grams of high-gly***ic CHO within three hours after an exercise bout and immediately before exercise have been shown to significantly stimulate muscle PRO synthesis.

• Daily post-exercise ingestion of a CHO + PRO supplement promotes greater increases in strength and improvements in lean tissue and body fat % during regular resistance training.

• Milk PRO sources (e.g. whey and casein) exhibit different kinetic digestion patterns and may subsequently differ in their support of training adaptations.

• Addition of Cr to a CHO + PRO supplement in conjunction with regular resistance training facilitates greater improvements in strength and body composition as compared with when no Cr is consumed.

• Dietary focus should center on adequate availability and delivery of CHO and PRO. However, including small amounts of fat does not appear to be harmful, and may help to control gly***ic responses during exercise.

• Irrespective of timing, regular ingestion of snacks or meals providing both CHO and PRO (3: 1 CHO: PRO ratio) helps to promote recovery and replenishment of muscle glycogen.

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Competing interests
The authors declare that they have no competing interests.

Authors' contributions

References
1.Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids [http://www.iom.edu/CMS/3788/4576/4340.aspx] webcite


Return to text


2.Bussau VA, Fairchild TJ, Rao A, Steele P, Fournier PA: Carbohydrate loading in human muscle: an improved 1 day protocol.

Eur J Appl Physiol 2002, 87:290-295. PubMed Abstract | Publisher Full Text

Return to text


3.Goforth HW, Laurent D, Prusaczyk WK, Schneider KE, Petersen KF, Shulman GI: Effects of depletion exercise and light training on muscle glycogen supercompensation in men.

Am J Physiol Endocrinol Metab 2003, 285(6):E1304-E1311. PubMed Abstract | Publisher Full Text

Return to text


4.Kavouras SA, Troup JP, Berning JR: The influence of low versus high carbohydrate diet on a 45-min strenuous cycling exercise.

Int J Sport Nutr Exerc Metab 2004, 14:62-72. PubMed Abstract

Return to text


5.Sherman WM, Costill DL, Fink WJ, Miller JM: Effect of exercise-diet manipulation on muscle glycogen and its subsequent utilization during performance.

Int J Sports Med 1981, 2:114-118. PubMed Abstract

Return to text


6.Yaspelkis BB, Patterson JG, Anderla PA, Ding Z, Ivy JL: Carbohydrate supplementation spares muscle glycogen during variable-intensity exercise.

J Appl Physiol 1993, 75:1477-1485. PubMed Abstract | Publisher Full Text

Return to text


7.Coyle EF, Coggan AR, Hemmert MK, Ivy JL: Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate.

J Appl Physiol 1986, 61:165-172. PubMed Abstract | Publisher Full Text

Return to text


8.Cribb PJ, Hayes A: Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy.

Med Sci Sports Exerc 2006, 38:1918-1925. PubMed Abstract | Publisher Full Text

Return to text


9.Tipton KD, Rasmussen BB, Miller SL, Wolf SE, Owens-Stovall SK, Petrini BE, Wolfe RR: Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise.

Am J Physiol Endocrinol Metab 2001, 281:E197-E206. PubMed Abstract | Publisher Full Text

Return to text


10.Willoughby DS, Stout JR, Wilborn CD: Effects of resistance training and protein plus amino acid supplementation on muscle anabolic, mass, and strength.

Amino Acids 2007, 32:467-477. PubMed Abstract | Publisher Full Text

Return to text


11.Coburn JW, Housh DJ, Housh TJ, Malek MH, Beck TW, Cramer JT, Johnson GO, Donlin PE: Effects of leucine and whey protein supplementation during eight weeks of unilateral resistance training.

J Strength Cond Res 2006, 20:284-291. PubMed Abstract | Publisher Full Text

Return to text



Eur J Appl Physiol 2007, 101:637-646. PubMed Abstract | Publisher Full Text

Return to text


13.White JP, Wilson JM, Austin KG, Greer BK, St John N, Panton LB: Effect of carbohydrate-protein supplement timing on acute exercise-induced muscle damage.

J Int Soc Sports Nutr 2008, 5:5. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text

Return to text


14.Coyle EF, Coggan AR, Hemmert MK, Lowe RC, Walters TJ: Substrate usage during prolonged exercise following a preexercise meal.

J Appl Physiol 1985, 59:429-433. PubMed Abstract | Publisher Full Text

Return to text


15.Tarnopolsky MA, Gibala M, Jeukendrup AE, Phillips SM: Nutritional needs of elite endurance athletes. Part I: Carbohydrate and fluid requirements.

Eur J Sport Sci 2005, 5:3-14. Publisher Full Text

Return to text


16.Joint Position Statement: nutrition and athletic performance. American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada

Med Sci Sports Exerc 2000, 32:2130-2145. PubMed Abstract | Publisher Full Text

Return to text


17.Gleeson M, Nieman DC, Pedersen BK: Exercise, nutrition and immune function.

J Sports Sci 2004, 22:115-125. PubMed Abstract | Publisher Full Text

Return to text


18.Sherman WM, Costill DL, Fink WJ, Hagerman FC, Armstrong LE, Murray TF: Effect of a 42.2-km footrace and subsequent rest or exercise on muscle glycogen and enzymes.

J Appl Physiol 1983, 55:1219-1224. PubMed Abstract | Publisher Full Text

Return to text


19.Earnest CP, Lancaster S, Rasmussen C, Kerksick C, Lucia A, Greenwood M, Almada A, Cowan P, Kreider R: Low vs. high gly***ic index carbohydrate gel ingestion during simulated 64-km cycling time trial performance.

J Strength Cond Res 2004, 18:466-472. PubMed Abstract | Publisher Full Text

Return to text


20.Febbraio MA, Keenan J, Angus DJ, Campbell SE, Garnham AP: Preexercise carbohydrate ingestion, glucose kinetics, and muscle glycogen use: effect of the gly***ic index.

J Appl Physiol 2000, 89:1845-1851. PubMed Abstract | Publisher Full Text

Return to text


21.Febbraio MA, Stewart KL: CHO feeding before prolonged exercise: effect of gly***ic index on muscle glycogenolysis and exercise performance.

J Appl Physiol 1996, 81:1115-1120. PubMed Abstract | Publisher Full Text

Return to text


22.Hawley JA, Burke LM: Effect of meal frequency and timing on physical performance.

Brit J Nutr 1997, 77:S91-S103. PubMed Abstract | Publisher Full Text

Return to text


23.Foster C, Costill DL, Fink WJ: Effects of preexercise feedings on endurance performance.

Med Sci Sports 1979, 11(1):1-5. PubMed Abstract

Return to text


24.Okano G, Takeda H, Morita I, Katoh M, Mu Z, Miyake S: Effect of pre-exercise fructose ingestion on endurance performance in fed men.

Med Sci Sports Exerc 1988, 20:105-109. PubMed Abstract

Return to text


25.Sherman WM, Peden MC, Wright DA: Carbohydrate feedings 1 h before exercise improves cycling performance.

Am J Clin Nutr 1991, 54:866-870. PubMed Abstract | Publisher Full Text

Return to text


26.Thomas DE, Brotherhood JR, Brand JC: Carbohydrate feeding before exercise: effect of gly***ic index.

Int J Sports Med 1991, 12:180-186. PubMed Abstract

Return to text


27.Chryssanthopoulos C, Hennessy LC, Williams C: The influence of pre-exercise glucose ingestion of endurance running capacity.

Br J Sports Med 1994, 28(2):105-109. PubMed Abstract | PubMed Central Full Text

Return to text


28.Devlin JT, Calles-Escandon J, Horton ES: Effects of preexercise snack feeding on endurance cycle exercise.

J Appl Physiol 1986, 60:980-985. PubMed Abstract | Publisher Full Text

Return to text


29.Hargreaves M, Costill DL, Fink WJ, King DS, Fielding RA: Effect of pre-exercise carbohydrate feedings on endurance cycling performance.

Med Sci Sports Exerc 1987, 19:33-36. PubMed Abstract

Return to text


30.McMurray RG, Wilson JR, Kitchell Bs: The effects of fructose and glucose on high intensity endurance performance.

Res Quart for Exerc and Sport 1983, 54:156-162.

Return to text


31.Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR: Ingestion of casein and whey proteins results in muscle anabolism after resistance exercise.

Med Sci Sports Exerc 2004, 36:2073-2081. PubMed Abstract | Publisher Full Text

Return to text


32.Candow DG, Burke NC, Smith-Palmer T, Burke DG: Effect of whey and soy protein supplementation combined with resistance training in young adults.

Int J Sport Nutr Exerc Metab 2006, 16:233-244. PubMed Abstract

Return to text


33.Febbraio MA, Chiu A, Angus DJ, Arkinstall MJ, Hawley JA: Effects of carbohydrate ingestion before and during exercise on glucose kinetics and performance.

J Appl Physiol 2000, 89:2220-2226. PubMed Abstract | Publisher Full Text

Return to text


34.Nicholas CW, Williams C, Lakomy HK, Phillips G, Nowitz A: Influence of ingesting a carbohydrate-electrolyte solution on endurance capacity during intermittent, high-intensity shuttle running.

J Sports Sci 1995, 13:283-290. PubMed Abstract | Publisher Full Text

Return to text


35.Widrick JJ, Costill DL, Fink WJ, Hickey MS, McConell GK, Tanaka H: Carbohydrate feedings and exercise performance: effect of initial muscle glycogen concentration.

J Appl Physiol 1993, 74:2998-3005. PubMed Abstract | Publisher Full Text

Return to text


36.Koopman R, Pannemans DL, Jeukendrup AE, Gijsen AP, Senden JM, Halliday D, Saris WH, van Loon LJ, Wagenmakers AJ: Combined ingestion of protein and carbohydrate improves protein balance during ultra-endurance exercise.

Am J Physiol Endocrinol Metab 2004, 287:E712-720. PubMed Abstract | Publisher Full Text

Return to text


37.Baty JJ, Hwang H, Ding Z, Bernard JR, Wang B, Kwon B, Ivy JL: The effect of a carbohydrate and protein supplement on resistance exercise performance, hormonal response, and muscle damage.

J Strength Cond Res 2007, 21:321-329. PubMed Abstract | Publisher Full Text

Return to text


38.Bird SP, Tarpenning KM, Marino FE: Liquid carbohydrate/essential amino acid ingestion during a short-term bout of resistance exercise suppresses myofibrillar protein degradation.

Metabolism 2006, 55:570-577. PubMed Abstract | Publisher Full Text

Return to text


39.Bird SP, Tarpenning KM, Marino FE: Effects of liquid carbohydrate/essential amino acid ingestion on acute hormonal response during a single bout of resistance exercise in untrained men.

Nutrition 2006, 22:367-375. PubMed Abstract | Publisher Full Text

Return to text


40.Haff GG, Koch AJ, Potteiger JA, Kuphal KE, Magee LM, Green SB, Jakicic JJ: Carbohydrate supplementation attenuates muscle glycogen loss during acute bouts of resistance exercise.

Int J Sport Nutr Exerc Metab 2000, 10:326-339. PubMed Abstract

Return to text


41.Bird SP, Tarpenning KM, Marino FE: Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men.

Eur J Appl Physiol 2006, 97:225-238. PubMed Abstract | Publisher Full Text

Return to text


42.McConell G, Snow RJ, Proietto J, Hargreaves M: Muscle metabolism during prolonged exercise in humans: influence of carbohydrate availability.

J Appl Physiol 1999, 87:1083-1086. PubMed Abstract | Publisher Full Text

Return to text


43.Fielding RA, Costill DL, Fink WJ, King DS, Hargreaves M, Kovaleski JE: Effect of carbohydrate feeding frequencies and dosage on muscle glycogen use during exercise.

Med Sci Sports Exerc 1985, 17:472-476. PubMed Abstract | Publisher Full Text

Return to text


44.Burke LM, Claassen A, Hawley JA, Noakes TD: Carbohydrate intake during prolonged cycling minimizes effect of gly***ic index of preexercise meal.

J Appl Physiol 1998, 85:2220-2226. PubMed Abstract | Publisher Full Text

Return to text


45.Patterson SD, Gray SC: Carbohydrate-gel supplementation and endurance performance during intermittent high-intensity shuttle running.

Int J Sport Nutr Exerc Metab 2007, 17:445-455. PubMed Abstract

Return to text


46.Dennis SC, Noakes TD, Hawley JA: Nutritional strategies to minimize fatigue during prolonged exercise: fluid, electrolyte and energy repla***ent.

J Sports Sciences 1997, 15:305-313. Publisher Full Text

Return to text


47.Jeukendrup AE: Carbohydrate intake during exercise and performance.

Nutrition 2004, 20:669-677. PubMed Abstract | Publisher Full Text

Return to text


48.Jeukendrup AE, Jentjens R: Efficacy of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research.

Sports Med 2000, 29:407-424. PubMed Abstract | Publisher Full Text

Return to text


49.Jeukendrup AE, Jentjens R, Moseley L: Nutritional Considerations in Triathlon.

Sports Med 2005, 35:163-181. PubMed Abstract | Publisher Full Text

Return to text


50.Jentjens R, Shaw C, Birtles T, Waring RH, Harding LK, Jeukendrup AE: Oxidation of combined ingestion of glucose and sucrose during exercise.

Metabolism 2005, 54(5):610-618. PubMed Abstract | Publisher Full Text

Return to text


51.Wallis GA, Rowlands DS, Shaw C, Jentjens R, Jeukendrup AE: Oxidation of combined ingestion of maltodextrins and fructose during exercise.

Med Sci Sports Exerc 2005, 37:426-432. PubMed Abstract | Publisher Full Text

Return to text


52.Jentjens R, Achten J, Jeukendrup AE: High rates of exogenous carbohydrate oxidation from multiple transportable carbohydrates ingested during prolonged exercise.

Med Sci Sports Exerc 2004, 36:1551-1558. PubMed Abstract | Publisher Full Text

Return to text


53.Jentjens R, Jeukendrup AE: High exogenous carbohydrate oxidation rates from a mixture of glucose and fructose ingested during prolonged cycling exercise.

Brit J Nutr 2005, 93:485-492. PubMed Abstract | Publisher Full Text

Return to text


54.Jentjens R, Moseley L, Waring RH, Harding LK, Jeukendrup AE: Oxidation of combined ingestion of glucose and fructose during exercise.

J Appl Physiol 2004, 96:1277-1284. PubMed Abstract | Publisher Full Text

Return to text


55.Jentjens R, Venables MC, Jeukendrup AE: Oxidation of exogenous glucose, sucrose, and maltose during prolonged cycling exercise.

J Appl Physiol 2004, 96:1285-1291. PubMed Abstract | Publisher Full Text

Return to text


56.Currell K, Jeukendrup AE: Superior endurance performance with ingestion of multiple transportable carbohydrates.

Med Sci Sports Exerc 2008, 40:275-281. PubMed Abstract

Return to text


57.Ivy JL, Res PT, Sprague RC, Widzer MO: Effect of a carbohydrate-protein supplement on endurance performance during exercise of varying intensity.

Int J Sport Nutr Exerc Metab 2003, 13:382-395. PubMed Abstract

Return to text


58.Saunders MJ, Kane MD, Todd MK: Effects of a carbohydrate-protein beverage on cycling endurance and muscle damage.

Med Sci Sports Exerc 2004, 36:1233-1238. PubMed Abstract | Publisher Full Text

Return to text


59.Saunders MJ, Luden ND, Herrick JE: Consumption of an oral carbohydrate-protein gel improves cycling endurance and prevents postexercise muscle damage.

J Strength Cond Res 2007, 21:678-684. PubMed Abstract | Publisher Full Text

Return to text


60.Beelen M, Koopman R, Gijsen AP, Vandereyt H, Kies AK, Kuipers H, Saris WH, van Loon LJ: Protein coingestion stimulates muscle protein synthesis during resistance-type exercise.

Am J Physiol Endocrinol Metab 2008, 295:E70-77. PubMed Abstract | Publisher Full Text

Return to text


61.Ivy JL: Glycogen resynthesis after exercise: Effect of carbohydrate intake.

Int J Sports Med 1998, 19:S142-S145. PubMed Abstract | Publisher Full Text

Return to text


62.Keizer H, Kuipers H, van Kranenburg G: Influence of liquid and solid meals on muscle glycogen resynthesis, plasma fuel hormone response, and maximal physical working capacity.

Int J Sports Med 1987, 8:99-104. PubMed Abstract

Return to text


63.Reed MJ, Brozinick JT, Lee MC, Ivy JL: Muscle glycogen storage postexercise: effect of mode of carbohydrate administration.

J Appl Physiol 1989, 66:720-726. PubMed Abstract | Publisher Full Text

Return to text


64.Conlee RK, Lawler RM, Ross PE: Effects of glucose or fructose feeding on glycogen repletion in muscle and liver after exercise or fasting.

Ann Nutr Metab 1987, 31:126-132. PubMed Abstract

Return to text


65.Jentjens R, Jeukendrup AE: Determinants of post-exercise glycogen synthesis during short-term recovery.

Sports Med 2003, 33:117-144. PubMed Abstract | Publisher Full Text

Return to text


66.Jentjens RLPG, van Loon L, Mann CH, Wagenmakers AJM, Jeukendrup AE: Addition of protein and amino acids to carbohydrates does not enhance postexercise muscle glycogen synthesis.

J Appl Physiol 2001, 91:839-846. PubMed Abstract | Publisher Full Text

Return to text


67.van Loon L, Saris WH, Kruijshoop M: Maximizing postexercise muscle glycogen synthesis: carbohydrate supplementation and the application of amino acid or protein hydrolysate mixtures.

Am J Clin Nutr 2000, 72:106-111. PubMed Abstract | Publisher Full Text

Return to text


68.Nichoas CW, Green PA, Hawkins RD: Carbohydrate intake and recovery of intermittent running capacity.

Int J Sport Nutr 1997, 7:251-260. PubMed Abstract

Return to text


69.Ivy JL, Goforth HW Jr, Damon BM, McCauley TR, Parsons EC, Price TB: Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement.

J Appl Physiol 2002, 93:1337-1344. PubMed Abstract | Publisher Full Text

Return to text


70.Zawadzki KM, Yaspelkis BB, Ivy JL: Carbohydrate-protein complex increases the rate of muscle glycogen storage after exercise.

J Appl Physiol 1992, 72:1854-1859. PubMed Abstract | Publisher Full Text

Return to text


71.Berardi JM, Price TB, Noreen EE, Lemon PW: Postexercise muscle glycogen recovery enhanced with a carbohydrate-protein supplement.

Med Sci Sports Exerc 2006, 38:1106-1113. PubMed Abstract | Publisher Full Text

Return to text


72.Tarnopolsky MA, Bosman M, Macdonald JR, Vandeputte D, Martin J, Roy BD: Postexercise protein-carbohydrate and carbohydrate supplements increase muscle glycogen in men and women.

J Appl Physiol 1997, 83:1877-1883. PubMed Abstract | Publisher Full Text

Return to text


73.Tipton KD, Ferrando AA, Phillips SM, Doyle DJ, Wolfe RR: Postexercise net protein synthesis in human muscle from orally administered amino acids.

Am J Physiol 1999, 276:E628-634. PubMed Abstract | Publisher Full Text

Return to text


74.Borsheim E, Tipton KD, Wolf SE, Wolfe RR: Essential amino acids and muscle protein recovery from resistance exercise.

Am J Physiol Endocrinol Metab 2002, 283:E648-657. PubMed Abstract | Publisher Full Text

Return to text


75.Pitkanen HT, Nykanen T, Knuutinen J, Lahti K, Keinanen O, Alen M, Komi PV, Mero AA: Free amino acid pool and muscle protein balance after resistance exercise.

Med Sci Sports Exerc 2003, 35:784-792. PubMed Abstract | Publisher Full Text

Return to text


76.Phillips SM, Tipton KD, Ferrando AA, Wolfe RR: Resistance training reduces the acute exercise-induced increase in muscle protein turnover.

Am J Physiol 1999, 276:E118-E124. PubMed Abstract | Publisher Full Text

Return to text


77.Biolo G, Tipton KD, Klein S, Wolfe RR: An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein.

Am J Physiol 1997, 273:E122-129. PubMed Abstract | Publisher Full Text

Return to text


78.Borsheim E, Cree MG, Tipton KD, Elliott TA, Aarsland A, Wolfe RR: Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exercise.

J Appl Physiol 2004, 96:674-678. PubMed Abstract | Publisher Full Text

Return to text


79.Tipton KD, Gurkin BE, Matin S, Wolfe RR: Nonessential amino acids are not necessary to stimulate net muscle protein synthesis in healthy volunteers.

J Nutr Biochem 1999, 10:89-95. PubMed Abstract | Publisher Full Text

Return to text


80.Miller SL, Tipton KD, Chinkes DL, Wolf SE, Wolfe RR: Independent and combined effects of amino acids and glucose after resistance exercise.

Med Sci Sports Exerc 2003, 35:449-455. PubMed Abstract | Publisher Full Text

Return to text


81.Tipton KD, Wolfe RR: Exercise, protein metabolism, and muscle growth.

Int J Sport Nutr Exerc Metab 2001, 11:109-132. PubMed Abstract

Return to text


82.Levenhagen DK, Gresham JD, Carlson MG, Maron DJ, Borel MJ, Flakoll PJ: Postexercise nutrient intake timing in humans is critical to recovery of leg glucose and protein homeostasis.

Am J Physiol Endocrinol Metab 2001, 280:E982-993. PubMed Abstract | Publisher Full Text

Return to text


83.Rasmussen BB, Tipton KD, Miller SL, Wolf SE, Wolfe RR: An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise.

J Appl Physiol 2000, 88:386-392. PubMed Abstract | Publisher Full Text

Return to text


84.Cribb PJ, Williams AD, Hayes A: A creatine-protein-carbohydrate supplement enhances responses to resistance training.

Med Sci Sports Exerc 2007, 39:1960-1968. PubMed Abstract | Publisher Full Text

Return to text


85.Cribb PJ, Williams AD, Stathis CG, Carey MF, Hayes A: Effects of whey isolate, creatine, and resistance training on muscle hypertrophy.

Med Sci Sports Exerc 2007, 39:298-307. PubMed Abstract | Publisher Full Text

Return to text


86.Hartman JW, Tang JE, Wilkinson SB, Tarnopolsky MA, Lawrence RL, Fullerton AV, Phillips SM: Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters.

Am J Clin Nutr 2007, 86:373-381. PubMed Abstract | Publisher Full Text

Return to text


87.Kerksick CM, Rasmussen CJ, Lancaster SL, Magu B, Smith P, Melton C, Greenwood M, Almada AL, Earnest CP, Kreider RB: The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training.

J Strength Cond Res 2006, 20:643-653. PubMed Abstract | Publisher Full Text

Return to text


88.Kerksick CM, Rasmussen C, Lancaster S, Starks M, Smith P, Melton C, Greenwood M, Almada A, Kreider R: Impact of differing protein sources and a creatine containing nutritional formula after 12 weeks of resistance training.

Nutrition 2007, 23:647-656. PubMed Abstract | Publisher Full Text

Return to text


89.Kreider RB, Earnest CP, Lundberg J, Rasmussen C, Greenwood M, Cowan P, Almada AL: Effects of ingesting protein with various forms of carbohydrate following resistance-exercise on substrate availability and markers of anabolism, catabolism, and immunity.

J Int Soc Sports Nutr 2007, 4:18. PubMed Abstract | BioMed Central Full Text | PubMed Central Full Text

Return to text


90.Tarnopolsky MA, Parise G, Yardley NJ, Ballantyne CS, Olatinji S, Phillips SM: Creatine-dextrose and protein-dextrose induce similar strength gains during training.

Med Sci Sports Exerc 2001, 33:2044-2052. PubMed Abstract | Publisher Full Text

Return to text


91.Wilkinson SB, Tarnopolsky MA, Macdonald MJ, Macdonald JR, Armstrong D, Phillips SM: Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage.

Am J Clin Nutr 2007, 85:1031-1040. PubMed Abstract | Publisher Full Text

Return to text


92.Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrere B: Slow and fast dietary proteins differently modulate postprandial protein accretion.

Proc Natl Acad Sci USA 1997, 94:14930-14935. PubMed Abstract | Publisher Full Text | PubMed Central Full Text

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[DIESELPWR]

I don't quite understand how you can dismiss the idea. It makes sense if you think about it. You are breaking down your muscles and depleting glycogen stores while working out.. So you would want to fuel them. You would rather use carbs for energy than wasting muscle. So you drink a simple carb to replenish your glycogen stores as quickly as possible to avoid this from happening.. Forget the "anabolic window" I just would rather replenish quickly instead of losing muscle. And eating oats in a shake is all well and good if that works for you but that is sustained energy that lasts over time and gives you energy through your day. I would just rather it get there as quickly as possible.. And everything else I mentioned are just creatine and amino acids. They are just free form and not branch chain..

[jasc]

TR, please post some cliff notes.. that's too much reading for us young guys

[Sgt. Hartman]

I don't quite understand how you can dismiss the idea. It makes sense if you think about it. You are breaking down your muscles and depleting glycogen stores while working out.. So you would want to fuel them. You would rather use carbs for energy than wasting muscle. So you drink a simple carb to replenish your glycogen stores as quickly as possible to avoid this from happening.. Forget the "anabolic window" I just would rather replenish quickly instead of losing muscle. And eating oats in a shake is all well and good if that works for you but that is sustained energy that lasts over time and gives you energy through your day. I would just rather it get there as quickly as possible.. And everything else I mentioned are just creatine and amino acids. They are just free form and not branch chain..

You're not "losing muscle" by not having your simple carbs directly after WO. The body is in a state of building up and tearing down (anabolic and catabolic) all day long, everyday, and whether there is a net catabolic or net anabolic effect at the end of the day depends on total calories and macros for the day. Calories in - Calories out. All these nutrient timing theories of perform this exercise then eat this, don't eat this then do cardio sound great on paper but the fact is the body is an amazingly adaptive machine that will ultimately adapt to whatever kind of nutrient timing you throw at it. BTW, I highly doubt you completely deplete your glycogen stores from 1 WO, even if you didn't have a preWO meal. But even if you did completely deplete them, it takes several hours to replenish muscle glycogen, regardless of the type or amount of carbs consumed. It is simply a process that takes time.

TR - I'll put something together for you to look at later this afternoon, I actually have some work to do right now.

We can go back and forth and post contradictory studies forever, but really all that matters to me is what makes me grow new muscle tissue and what doesn't. All the theories and studies in the world don't mean shit to me if they don't help me grow......

[jimmyinkedup]

Ok so a few points;
1- Glycogen replenishemnt will occur regardless of simple carbs ingested post work out or not. There is no benfit whatsoever to this happening "faster" unless for example one is doing 2 a day practices where u lift in amand have field practice in pm or if you are say competeing in a decathalon where you do strength and endurance acitivites in the same day. Faster gylcogen replenishment in no way = greater muscle.

2- Insulin and the anabolic response. Endegenous insulin cannot be stimuated enough by ingestion of high quantities of simple carbs to promote an anbolic repsonse that is significant enough to make a differecne in lean body mass. There are several ways this can be proven but lets just rely on common sense and leave it at that. If this insulin/anabolic response were true would it not be prudent to ingest simple carbs and pritein all day - have insulin levels elevated and be in this magical anabolic state building more muscle. As we all know that simply isnt the case. Also one can take glucophage - now some think it is a simple gda however it has a 3 way mechanism of action - basically in improves the bodies insulin response as well as glucose diosposal and also improves insulin sensatrivity. Yet doing all thsese things one can take it daily and it offers no change in body composition whatsoever. This essentially proves that endegenous insulin manipultion to add lean body mass at a greater rate is an exercise in futility.

3- Shutting of nutrients. I like this one. The fact is it doesnt matter how quickly they get there - ultimately they will get there eithert way and having it occur more quickly doesnt equal more muscle being built. In fact mosts supps that say they do this dont anyway and the insulin spike theory isnt prudent as the body is an adaptive mechnaism that will simply lower insulin relase later so the end result is ultimately the same.

4- So now lets talk about the cost of ingestion of anywhere from 50-90 grams of pure sugar all at once. Do we evern have too? From a general health standpoint its pretty obvious why this isnt prudent - in fact its pretty detrimental.

All in all it really is a modality and pratctice borught to the forefront by supplement company rhetoric (primarily cell tech) that has somehow stuck. As was mentioned earlier ITT the formost nutritional minds in bodybuilding see this and call it for what it is - which really amounts to hype driven nonsense. The whole nutrient timing concept is being totlally debunked theoretically and practically on a daily basis anymore. For those interested read Lyle McDonald , Jamie Hale , Will Brink , and Alan Aragon. Also Layne Norton , while he was early on a proponent of nutrient timing , is now of the school of thought that its realtively insignificant, In fact he rolled out a new concept that uses BCAA's is a semi fatsed tyoe diet to decrease DOMS and potentially increase protein synthesis. There is a great blog on Alan Aragon Blog called nutrition roundtable - its him and will brink and jamie hale all discussing nutrition - its an amazing read I highly recommend it. Lastly and finally if you are one that insists on sticking with the simple carbs post workout I strongly encourage you to do so in a more prudent way such as ingestion of fruits such as pineapple , bananas , rasins etc if for no other reason simply for the sake of basic common sense nutrition.

[Sgt. Hartman]

First, let me say that IMO studies on how individuals respond to nutrition are fairly futile as there are too many variables on how people respond to nutrition based on genetics, body composition, insulin sensitivities, etc. These studies can also be manipulated in order to produce the desired outcome very easily, especially when it is unknown how the study was funded (supplement companies) or the credentials of the person/people performing the study. That being said, here are some studies that would directly contradict the studies that Times posted above. I am NOT necessarily saying that I agree with the conclusions.


Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis.
Koopman R, Beelen M, Stellingwerff T, Pennings B, Saris WH, Kies AK, Kuipers H, van Loon LJ.
Source
Department of Movement Sciences, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands. [email protected]
Abstract
The present study was designed to assess the impact of coingestion of various amounts of carbohydrate combined with an ample amount of protein intake on postexercise muscle protein synthesis rates. Ten healthy, fit men (20 +/- 0.3 yr) were randomly assigned to three crossover experiments. After 60 min of resistance exercise, subjects consumed 0.3 g x kg(-1) x h(-1) protein hydrolysate with 0, 0.15, or 0.6 g x kg(-1) x h(-1) carbohydrate during a 6-h recovery period (PRO, PRO + LCHO, and PRO + HCHO, respectively). Primed, continuous infusions with L-[ring-(13)C(6)]phenylalanine, L-[ring-(2)H(2)]tyrosine, and [6,6-(2)H(2)]glucose were applied, and blood and muscle samples were collected to assess whole body protein turnover and glucose kinetics as well as protein fractional synthesis rate (FSR) in the vastus lateralis muscle over 6 h of postexercise recovery. Plasma insulin responses were significantly greater in PRO + HCHO compared with PRO + LCHO and PRO (18.4 +/- 2.9 vs. 3.7 +/- 0.5 and 1.5 +/- 0.2 U.6 h(-1) x l(-1), respectively, P < 0.001). Plasma glucose rate of appearance (R(a)) and disappearance (R(d)) increased over time in PRO + HCHO and PRO + LCHO, but not in PRO. Plasma glucose R(a) and R(d) were substantially greater in PRO + HCHO vs. both PRO and PRO + LCHO (P < 0.01). Whole body protein breakdown, synthesis, and oxidation rates, as well as whole body protein balance, did not differ between experiments. Mixed muscle protein FSR did not differ between treatments and averaged 0.10 +/- 0.01, 0.10 +/- 0.01, and 0.11 +/- 0.01%/h in the PRO, PRO + LCHO, and PRO + HCHO experiments, respectively. In conclusion, coingestion of carbohydrate during recovery does not further stimulate postexercise muscle protein synthesis when ample protein is ingested.




Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men.
Burd NA, West DW, Moore DR, Atherton PJ, Staples AW, Prior T, Tang JE, Rennie MJ, Baker SK, Phillips SM.
Source
Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
Abstract
We aimed to determine whether an exercise-mediated enhan***ent of muscle protein synthesis to feeding persisted 24 h after resistance exercise. We also determined the impact of different exercise intensities (90% or 30% maximal strength) or contraction volume (work-matched or to failure) on the response at 24 h of recovery. Fifteen men (21 ± 1 y, BMI = 24.1 ± 0.8 kg · m(-2)) received a primed, constant infusion of l-[ring-(13)C(6)]phenylalanine to measure muscle protein synthesis after protein feeding at rest (FED; 15 g whey protein) and 24 h after resistance exercise (EX-FED). Participants performed unilateral leg exercises: 1) 4 sets at 90% of maximal strength to failure (90FAIL); 2) 30% work-matched to 90FAIL (30WM); or 3) 30% to failure (30FAIL). Regardless of condition, rates of mixed muscle protein and sarcoplasmic protein synthesis were similarly stimulated at FED and EX-FED. In contrast, protein ingestion stimulated rates of myofibrillar protein synthesis above fasting rates by 0.016 ± 0.002%/h and the response was enhanced 24 h after resistance exercise, but only in the 90FAIL and 30FAIL conditions, by 0.038 ± 0.012 and 0.041 ± 0.010, respectively. Phosphorylation of protein kinase B on Ser473 was greater than FED at EX-FED only in 90FAIL, whereas phosphorylation of mammalian target of rapamycin on Ser2448 was significantly increased at EX-FED above FED only in the 30FAIL condition. Our results suggest that resistance exercise performed until failure confers a sensitizing effect on human skeletal muscle for at least 24 h that is specific to the myofibrillar protein fraction.


IJSNEM Volume 19, Issue 2, April
Original Research

Effect of Protein-Supplement Timing on Strength, Power, and Body-Composition Changes in Resistance-Trained Men

The effect of 10 wk of protein-supplement timing on strength, power, and body composition was examined in 33 resistance-trained men. Participants were randomly assigned to a protein supplement either provided in the morning and evening (n = 13) or provided immediately before and immediately after workouts (n = 13). In addition, 7 participants agreed to serve as a control group and did not use any protein or other nutritional supplement. During each testing session participants were assessed for strength (one-repetition-maximum [1RM] bench press and squat), power (5 repetitions performed at 80% of 1RM in both the bench press and the squat), and body composition. A significant main effect for all 3 groups in strength improvement was seen in 1RM bench press (120.6 ± 20.5 kg vs. 125.4 ± 16.7 at Week 0 and Week 10 testing, respectively) and 1RM squat (154.5 ± 28.4 kg vs. 169.0 ± 25.5 at Week 0 and Week 10 testing, respectively). However, no significant between-groups interactions were seen in 1RM squat or 1RM bench press. Significant main effects were also seen in both upper and lower body peak and mean power, but no significant differences were seen between groups. No changes in body mass or percent body fat were seen in any of the groups. Results indicate that the time of protein-supplement ingestion in resistance-trained athletes during a 10-wk training program does not provide any added benefit to strength, power, or body-composition changes.


IJSNEM Volume 18, Issue 1, February
Original Research

Carbohydrate-Protein Drinks Do Not Enhance Recovery From Exercise-Induced Muscle Injury

This study examined the effects of carbohydrate (CHO), carbohydrate-protein (CHO+PRO), or placebo (PLA) beverages on recovery from novel eccentric exercise. Female participants performed 30 min of downhill treadmill running (–12% grade, 8.0 mph), followed by consumption of a CHO, CHO+PRO, or PLA beverage immediately, 30, and 60 min after exercise. CHO and CHO+PRO groups (n = 6 per group) consumed 1.2 g · kg body weight–1 · hr–1 CHO, with the CHO+PRO group consuming an additional 0.3 g · kg body weight–1 · hr–1 PRO. The PLA group (n = 6) received an isovolumetric noncaloric beverage. Maximal isometric quadriceps strength (QUAD), lower extremity muscle soreness (SOR), and serum creatine kinase (CK) were assessed preinjury (PRE) and immediately and 1, 2, and 3 d postinjury to assess exercise-induced muscle injury and rate of recovery. There was no effect of treatment on recovery of QUAD (p = .21), SOR (p = .56), or CK (p = .59). In all groups, QUAD was reduced compared with PRE by 20.6% ± 1.5%, 17.2% ± 2.3%, and 11.3% ± 2.3% immediately, 1, and 2 d postinjury, respectively (p < .05). SOR peaked at 2 d postinjury (PRE vs. 2 d, 3.1 ± 1.0 vs. 54.0 ± 4.8 mm, p < .01), and serum CK peaked 1 d postinjury (PRE vs. 1 d, 138 ± 47 vs. 757 ± 144 U/L, p < .01). In conclusion, consuming a CHO+PRO or CHO beverage immediately after novel eccentric exercise failed to enhance recovery of exercise-induced muscle injury differently than what was observed with a PLA drink.



Obviously, anyone can find studies to support whichever opinion they have. The whole idea of the 45min anabolic window isn't dead wrong, it's timing is just off - it should be called the 24hr anabolic window. There is absolutely nothing wrong with having a whey shake with carbs immediately following WO, hell I do it 5 days a week. It's not counterproductive, it's just not necessary. The whole idea that if we don't have the pro/carb shake within 45min or we'll "go catabolic" or we'll miss out on the window for maximum protein synthesis is just ridiculous. Protein synthesis will occur to the same extent whether the PWO meal is consumed 2min PWO or 2hrs PWO. It is your daily overall nutrition that controls your body weight and affects your body composition, not the timing of your nutrition intake.

Here's what Alan Aragon says:

When speaking of nutrition for improving body composition or training performance, it's crucial to realize there's an underlying hierarchy of importance. At the top of the hierarchy is total amount of the macronutrients by the end of the day. Distantly below that is the precise timing of those nutrients. With very few exceptions, athletes and active individuals eat multiple times per day. Thus, the majority of their day is spent in the postprandial (fed) rather than a post-absorptive (fasted) state. The vast majority of nutrient timing studies have been done on overnight-fasted subjects put through glycogen depletion protocols, which obviously limits the applicability of the outcomes. Pre-exercise (and/or during-exercise) nutrient intake often has a lingering carry-over effect into the post-exercise period. Throughout the day, there's a constant overlap of meal digestion & nutrient absorption. For this reason, the effectiveness of nutrient timing does not require a high degree of precision.

The Primary Laws of Nutrient Timing
The First Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.
The Second Law of Nutrient Timing is: hitting your daily macronutrient targets is FAR more important than nutrient timing.

The post-exercise “anabolic window” is a highly misused & abused concept. Preworkout nutrition all but cancels the urgency, unless you’re an endurance athlete with multiple glycogen-depleting events in a single day. Getting down to brass tacks, a relatively recent study (Power et al. 2009) showed that a 45g dose of whey protein isolate takes appx. 50 minutes to cause blood AA levels to peak. Resulting insulin levels, which peaked at 40 minutes after ingestion, remained at elevations known to max out the inhibition of muscle protein breakdown (15-30 mU/L) for 120 minutes after ingestion. This dose takes 3 hours for insulin & AA levels to return to baseline from the point of ingestion. The inclusion of carbs to this dose would cause AA & insulin levels to peak higher & stay elevated above baseline even longer.
So much for the anabolic peephole & the urgency to down AAs during your weight training workout; they are already seeping into circulation (& will continue to do so after your training bout is done). Even in the event that a preworkout meal is skipped, the anabolic effect of the postworkout meal is increased as a supercompensatory response (Deldicque et al, 2010). Moving on, another recent study (Staples et al, 2010) found that a substantial dose of carbohydrate (50g maltodextrin) added to 25g whey protein was unable to further increase post-exercise net muscle protein balance compared to the protein dose without carbs. Again, this is not to say that adding carbs at this point is counterproductive, but it certainly doesn’t support the idea that you must get your lightning-fast post-exercise carb orgy for optimal results.
Something that people don’t realize is that there’s no “magic anabolic window” that’s open for a short period of time near the workout & then rapidly disappears. As a result of a single training bout, the receptivity of muscle to protein dosing can persist for at least 24 hours (Burd et al, 2011).
The "windows" for taking advantage of nutrient timing are not little peepholes. They're more like bay windows of a mansion. You're ignoring just how long the anabolic effects are of a typical mixed meal. Depending on the size of a meal, it takes a good 1-2 hours for circulating substrate levels to peak, and it takes a good 3-6 hours (or more) for everythng to drop back down to baseline.
You're also ignoring the fact that the anabolic effects of a meal are maxed out at much lower levels than typical meals drive insulin & amino acids up to. Furthermore, you're also ignoring the body's ability of anabolic (& fat-oxidative) supercompensation when forced to work in the absence of fuels. So, metaphorically speaking, our physiology basically has the universe mapped out and you're thinking it needs to be taught addition & subtraction.

By Dave Barr on the Anabolic Window:
You may be wondering: is this a myth because the real window is half an hour? Two or 3 hours? Maybe 6 hours? Sadly, in the past 2 weeks I’ve read different articles, all suggesting that the "window" is one of the above lengths of time.
It’s not surprising that with this type of inconsistency that this is probably the most pervasive myth in bodybuilding today! Worse yet, it stems directly from the scientific research itself. The most often cited research on the protein synthetic post workout window, used elderly subjects (Esmark et al., 2001) and cardio exercise findings (Levenhagen et al., 2001) to make their predictions. While this is a completely acceptable practice when these are the only data we have to go on, there are a couple noteworthy problems.
Elderly individuals digest and absorb protein differently than healthy adults. In fact, they digest and absorb whey protein in a similar manner as they do casein (Dangin et al., 2003); in other words they have slow digestion and absorption for whey. Elderly also benefit from having 80% of their daily protein consumed at a single sitting (Arnal et al., 1999), in contrast to the benefits of our multiple feedings.
Additionally, the traditionally referenced Esmark et al. (2001), study showed that consuming the post workout meal just 2 hours after working out actually prevented any improvements induced by the training! Figure that one out and you get a prize.
Secondly, with regards to cardio…well, let’s just say that there’s an obvious difference between how our muscles respond to the two forms of exercise. Bear in mind that with regard to carbohydrate metabolism following a workout, there might not be much of a difference—we just don’t know, but certainly the long-term protein metabolism differences can be seen.
So now what are we supposed to base our nutrition on? Enter the most underrated scientific paper in the last 5 years. Tipton and colleagues (2003) examined responsiveness of protein synthesis for a day after a workout, and found it to reflect a 24 hour enhanced level. That’s right folks, a FULL DAY! This means that having a morning shake will have the same impact on muscle protein synthesis as one consumed following the workout!
These results shouldn’t be too surprising because we’ve known for over a decade that postworkout protein synthesis is jacked up for this long (MacDougall et al., 1995), but if you’re discovering this for the first time, then it’s pretty exciting!
Some research suggests that even 48 hours after the workout our protein synthesis levels can be elevated by ~33% (Phillips et al., 1997), giving us an even longer period during which we can maximize our muscle growth with protein drinks.

It’s amazing to see how more advanced, and often experienced, people behave in the gym when it comes to getting their post workout meal. Some guys even sit there, right after their last set, and slug back a drink! In fact I’ve even heard "as soon as the weight hits the floor" touted as the war cry for the hardcore. While this is actually a sub-optimal practice for muscle growth and recovery, not to mention borderline obsessive compulsive, it’s good to see their heart is the right place.
Comparing research that used drinks consumed immediately after a workout (Tipton et al., 2001) versus those ingested an hour after training (Rasmussen et al., 2000), the results are surprising: it seems that post workout meal ingestion actually results in 30% lower protein synthesis rates than when we wait! So every time we thought that we were badass for drinking "as soon as the weight hit the floor, we were actually short changing ourselves. Not a big deal, that’s why we read *******. Let’s just learn, adapt, and move on.

The term insulin sensitivity gets thrown around in the strength-training world, as only the most vague of concepts. From here on, lets universally define it as: the inverse of the quantity of insulin required for an effect of a given magnitude. In other words, high insulin sensitivity requires low levels of insulin to do the job. Make sense? Now that we have a working definition, we need to destroy the myth of the one-hour post workout window once and for all!
We know that both endurance exercise and strength training will enhance insulin sensitivity in the long term. This is a good thing. Unfortunately, with all of the hype surrounding the post workout window, people have started throwing out numbers related to how long insulin sensitivity is altered. While we know that heavily damaging eccentric exercise will actually reduce insulin sensitivity (Asp et al., 1996), this should be an extreme condition and not our regular response. So if you’ve overdone it a bit, back off and heal up!
The more common response to strength training is an increase in insulin sensitivity (Fujitani et al., 1998; Miller et al, 1984), and brand new data show even the acute effect from a single bout lasts for over 24 hours (Koopman et al., 2005). So while we’ll have an enhanced whole body insulin sensitivity following resistance training, this effect is even greater for 24 hours following exercise!

[Times Roman]

an intelligent discussion!

enjoyable and informative. Let me digest this now and.......

[gbrice75]

I'm late to the party, and would have expected to see this in the diet section, not the freakin' lounge - but this is where Diesel hangs out!!!

There's not much I can say that Sgt. Hartman, Baseline, and Jimmy haven't already said. Sgt. Hartman in particular hit the nail on the head.

Recent (as within the past 2 years or so, I will dig them up when I have time) studies have shown that protein synthesis actually INCREASES after several hours PWO, supporting the idea that ongoing nutrition throughout the day and on is important, more important than that PWO meal your muscles are 'starving' for. Read my cutting 101 sticky in the diet section http://forums.steroid.com/showthread...g#.TsvrSz2BrBI as I address this briefly.

As for glycogen replenishment... if you think you're depleting glycogen stores from your workout, you are sadly mistaken. It takes ALOT to deplete glycogen. I do it purposely, every week, and it takes me 3 zero carb days + alot of cardio and total body/high intensity type workouts. Your hour long workout consisting of bench press, shoulder press, and curls is HARDLY touching your glycogen stores. This is especially true for people who are consuming carbs on a daily basis. You are topping off your semi-depleted stores at best, and more likely burning dietary carbs (readily available glucose) assuming you have carbs in your preworkout meal, plain and simple. The idea that you need a fast acting carb source to counter-act muscle breakdown after a workout is old, outdated, debunked, and asinine if you know a bit about human physiology. Dextrose is about the last thing i'd waste my money on, and the last thing i'd purposely ingest.

[awms]

Here is how your body works in simple terms so every person can understand:

first 10 sec energy source used: ATP-CP (stored in your muscle)

10 seconds to 2 mins: Glycogen & blood glucose are used to make ATP

2 mins plus: aerobic system kicks in and oxygen + glycogen/glucose or fat is used for energy.

What does this mean?

Well let say for argument sake that 90% of the people in here are "bodybuilding" which means we are mostly working with the anaerobic (No oxygen is used 10 sec to 2mins) so we use mostly muscle glycogen or "carbs" for fuel. Now if your pushing your self hard! (90 to 100% of max) your body is going to be rapidly using glycogen stores to create ATP during your workout. Since no one person is the same the amount of glycogen or "carbs" used will differ from person to person but what I can tell you is that it is very easy to use up 80 plus grams of carbs in an hour workout if your really pushing your self!

I personally use around 100g plus grams of carbs post workout and have never had a problem with this other feeling a bit tired from the insulin spike. If your really worried about geting fat then do 10-15 mins of intervals post workout to deplete glycogen stores.

You can post any study in the world arguing against what I have just posted but that is how the body works and if you ask any top trainer, athlete, or pro bodybuilder they will tell you they use the method I have posted....there lots of so called "gurus" who will tell you if you elephant penis and take their pill you will grow bigger then a truck! lol listen to what works and what has worked for years!

[Sgt. Hartman]

********

[jimmyinkedup]

Here is how your body works in simple terms so every person can understand:

first 10 sec energy source used: ATP-CP (stored in your muscle)

10 seconds to 2 mins: Glycogen & blood glucose are used to make ATP

2 mins plus: aerobic system kicks in and oxygen + glycogen/glucose or fat is used for energy.

What does this mean?

To me it means the body is a beautiful and amazing complex organism (which is even simplified in your example) which merely proves to me that selling it short by buying into "nutrient timing" theories does it a grave disservice. I do not see one thing you posted that shows repelinshing glycogen faster is in any way beneficial or results in more muscle. One must compare the overall cost from a health perspective before considering the ingestion of 100g of pure sugar all at once - then factor in does it ultimately equal more muscle or make any difference in results- before partaking in an abviously nutritionally (from a health perspective) foolish endeavor. The logic of "i do it , others do it , you should do it too" doesnt fly with me. Also if you ask any top bodybuilder that question you should preface it with how many iu's of insulin are you injecting prioer to this massive ingestion of sugar. Also I dont belive that contention of "all top trainers , atheletes and bodybuilders do it". I think that is false. To each his own and i post this strictly with the intention of expressing my opinion and fostering good debate - not demeaning anyone elses opinion.

[awms]

To me it means the body is a beautiful and amazing complex organism (which is even simplified in your example) which merely proves to me that selling it short by buying into "nutrient timing" theories does it a grave disservice. I do not see one thing you posted that shows repelinshing glycogen faster is in any way beneficial or results in more muscle. One must compare the overall cost from a health perspective before considering the ingestion of 100g of pure sugar all at once - then factor in does it ultimately equal more muscle or make any difference in results- before partaking in an abviously nutritionally (from a health perspective) foolish endeavor. The logic of "i do it , others do it , you should do it too" doesnt fly with me. Also if you ask any top bodybuilder that question you should preface it with how many iu's of insulin are you injecting prioer to this massive ingestion of sugar. Also I dont belive that contention of "all top trainers , atheletes and bodybuilders do it". I think that is false. To each his own and i post this strictly with the intention of expressing my opinion and fostering good debate - not demeaning anyone elses opinion.

there are many benefits taking carbs post workout! Yes to much sugar in a persons diet can affect their health but its all about timing!

Carbs post workout:

Lowers cortisol levels: Cortisol peaks during/post workout and has damaging effects on the body and muscle

Spikes insulin : Insulin drives nutrients like glucose, amino acids and even creatine into muscle cells

Replenishes glycogen stores: Without glyogen in the muscle the body will break down amino acids or muscle for fuel

The only time when I would say taking in carbs post workout would hinder you is if you were trying to loose fat...in this case protein and amino acids would be fine.

[awms]

The bottom line is this. If you want to get max results you need to take in post workout carbs! yes you can make gains without them but the body works better with them and thats been proven over and over....you can say "the body isnt meant to have large amounts of carbs" which is true for the avg person but we are not the avg. person! we lift alot more, put out bodies threw alot more! the body also is not meant to lift large objects for hours at a time....so our diet plan is going to differ from the average joe walking down the street.

[Times Roman]

OK, so I must ask you experienced members to rate this website
http://www.jissn.com/
it is the international society of sports nutrition

is this organization biased towards those that supplement athletes? they say not, and the articles are peer reviewed. I may start a thread on this to raise the visibility of this question. With so many conflicting studies, it is extremely difficult to determine which is right. I am interested in GB's data he mentioned above.

So please take a look at the website (not trying to become a spammer or sponsor in any way), and look at it to see if you feel it is biased or not.

I'd appreciate it

Thanks

[DIESELPWR]

Good read times.. The discussion I brought up, plus wrestling.. Looks good in my book.. I'm glad this subject made such an interesting debate.

[Times Roman]

bump for the evaluation of this website please?

http://www.jissn.com/

see frame #37 for detail

[jimmyinkedup]

^^ without a doubt a well respected source of data....