Why does fasted cardio work better?
Anabolic Member
Why does fasted cardio work better?
Senior Member
theory behind it is that you have lil to no glycogen/food stores to burn through first so you are burning pure bodyfat throughtout entire cardio session...... I have a very hard time believing that you are not burning muscel too tho.
VET
Because your body has been starved of glucose (the preferred energy source) all night during sleep, so your body must find an alternative source of fuel - hopefully fat.
Doing types of high intensity cardio AM fasted is not a good idea though because the body can convert muscle stores into glucose through a process called gluconeogenesis as fat is not an efficient energy source for higher intensity cardio workouts.
AR's Diet Pimp! ~HOF~
It hasn't been proven beyond a doubt that fasted cardio works 'better' or is more beneficial than fed state cardio. Personally, it makes sense to me so long as intensity is kept relatively low, but fed state intervals/higher intensity cardio is great as well.Originally Posted by Dr Pepper
I believe it comes down to personal preference and schedule. i.e. if am cardio is the only time you can do it and you aren't going to weight train during that window, fasted makes sense IMO.
9/11/2001~343 Never Forget!~E-HOF~RETIRED
Per Chris Aceto
Cardio is a good fat burner. However, cardio can be a great fat burner if we look for ways to maximize the amount of body fat burned during cardio sessions. One of the easiest ways to encourage maximal fat burning is to do your cardio in the morning on a completely empty stomach, soon after rising and before eating. The reason is simple, in a “fasting” state (Ex. not having eaten for probably close to 10 hours), glucose – the basic energy component found on carbohydrates – circulates within the bloodstream at its lowest levels of the day. When this occurs, the body is more likely to turn to stored fuel – body fat – as energy. Upon the introduction of cardio, the body begins to look for fuel. If there are no significant amounts of glucose, the body responds by immediately digging into body fat stores for energy. Bingo.
The body will not utilize deep fat stores for energy during cardio if you have eaten before performing cardio. Instead, it will first take a look at what has recently been ingested – what you have eaten – and try to use that first before starting to utilize stores of body fat. Even a small meal, or a small carbohydrate snack, can inhibit fat burning by slowing the rate at which your body begins its search for stored body fat. Carbohydrates quickly digest into glucose, which alters the speed at which the body burns fat. In essence, food consumed before cardio exercise acts as a slowing agent, altering the body’s ability to burn body fat. On the other hand, with no food, there is no slowing effect and the body can quickly start burning body fat. Glucose, the digested form of carbohydrates, plays a big role in determining your fat burning status. With low levels, fat burning increases. With high levels of glucose, fat burning dramatically slows. To ensure you are burning as much body fat as possible, schedule your aerobic sessions in the morning, without food, to keep glucose levels flat.
The second reason to avoid eating before cardio exercise has to do with our pesky little friends, hormones. With a lack of food in the body, the prevailing hormones that kick into play immediately upon aerobic exercise are catecholamines and glucagon (try saying that five times fast). Catecholamines are tiny messengers released from the adrenal glands that are dumped into the blood with exercise. Their job is to target fat cells, helping them to open up, allowing fat to be liberated and burned as fuel. However, when you eat food, specifically carbohydrates, catecholamines become less effective at doing what you want them to do – help breakdown body fat. Glucagon is the second fat burning stimulus that increases upon exercise, especially when there is a lack of food in the body. Glucagon is a major player in fat burning as it helps kick start the entire fat burning process. Glucagon helps tear down fat cells and upgrade the enzymes that use body fat as energy. Specifically, glucagon supports the production of hormone sensitive lipase, (HSL) a gatekeeper on fat cells that helps determine the flow of fat. When HSL is active, it allows more fatty acids from body fat to flow into the blood where they can be burned as fuel. On the other hand, when HSL falls, the flow of fatty acids out of fat cells becomes greatly impaired. In addition, glucagon suppresses the activity of Malonyl CoA and supports Carnitine Palmityl Transferase 1 (CPT-1). Malonyl CoA influences the liver’s ability to start the fat building or fat storing process. As Malonyl CoA activity rises, fat storage increases and as it drops – by avoiding food before cardio- fat burning increases. CPT-1 is another enzyme that supports the burning of body fat by dragging fatty acids –from body fat – into muscle cells, where they are burned. When you avoid eating before cardio and allow the maximum production of glucagon, you’ll experience greater CPT-1 activity which facilitates the burning of body fat. On the other hand, when you eat before cardio, all these mechanisms are compromised; less potent catecholamine activity with negligible glucagon production translating into less active fat burning.
Another point on eating before cardio is that food, especially carbohydrates, increase insulin levels. Generally, insulin is known as a fat storing hormone. It makes catecholamines less effective at triggering the breakdown of body fat and it also suppresses the release of glucagon. Remember, our little friend glucagon is the chief hormone that sets in place fat burning and support (Glucagon sounds like a Transformer). Surprisingly, it does not take a lot of food to increase insulin levels and to block the maximal fat burning effects of aerobic exercise. Even a small piece of toast is enough in to trigger sufficient insulin production to set in motion a hormonal change to mildly interrupt or slow the fat burning effects of a hard 30-40 minute cardio session. In the world of maximizing fat loss, it’s just not a good idea to eat before cardio.
A lot of bodybuilders argue adding cardio to the end of a weight training session will exert the same effect as doing cardio in the morning on an empty stomach. The idea: weight training depletes the body of sugar in the blood, (glucose) which is akin to a fasting state. In other words, the hard training empties fuel from the bloodstream and when this occurs, it’s a great time to do cardio. They’re half right. Hardcore training does burn through glucose in the blood and it even lowers muscle glycogen stores. Both can favor the burning of body fat. If you jump on the treadmill after training, you might expect catecholamines, already floating about as a result of training, to target fat cells. In addition, with low glucose levels, you might also expect glucagon levels to be elevated. These two points can be considered true. However, the problem is duration. When training sessions become too long – be it cardio or weight training, catabolism (muscle breakdown!) sets in. Cortisol – a hormone that causes muscle breakdown – can rise too high as a result. When cardio is done after a weight training session, cortisol – one of the chief muscle wasting hormones – rises to unreasonable levels. Studies have shown cortisol to lower testosterone levels and trigger a rapid spike in free radicals. Free radicals ignite muscle inflammation, thereby knocking out the immune system and paralyzing muscle recovery. When you follow up your weight training sessions with cardio, you push the body over the edge into a quasi overtraining state. In this state, hormones like testosterone and other anabolic hormones in the body decline. As a result, it becomes very difficult to retain muscle mass.
Testosterone levels. They are the other reason that I am a huge “cardio in the morning advocate. Some studies indicate testosterone levels are higher in the morning and decline from there, only to experience a late afternoon surge. Doing cardio in the morning makes sense as it is scheduled at a time where one of the most anabolic hormones – testosterone – is at its peak. The higher testosterone level can act as an anti-catabolic, preserving muscle mass. By definition, aerobics is a potentially catabolic event. It does not “build the body up” but rather “tears it down.” We always hope that we are tearing down body fat to be used as fuel. Still, with a poor nutrition strategy or if you are borderline overtrained, aerobics can become truly catabolic. It can lower testosterone levels causing a loss of metabolic supporting muscle mass! Having a hormonal profile that is higher in testosterone levels will help spare the body from eating away at its own muscle. Crushing your cardio in the morning is the best way to ensure you can burn fat without sacrificing muscle mass.
Anabolic Member
very good read, thanks fireguy... do you think something as small as a coffee before cardio in the am could have an effect on glucose levels?
9/11/2001~343 Never Forget!~E-HOF~RETIRED
I would think coffee would be just fine as long as you dont decorate it with a bunch of sugar.
Pissing Excellence!
fireguy, thanks for the read. twist has me doing fasted cardio and i am loving it! is there a breaking point to where your body will go into breaking down protein for energy? i am getting to about 250cals burning, when my stomach just aches with hunger pains. i stay doing the workout until i reach 350cals. i will be trying some BCAA's to see if this helps some. what are your thoughts on taking vit c before doing AM fasted cardio?
Knowledgeable Member
My coach suggest some small protein source such as a small chicken breast. Her theory is that it feeds the muscle (the protein) and wont be used during the fasted cardio session. Any thoughts?
Anabolic Member
How long is your fasted cardio session going for?
Anabolic Member
I guess that's correct to keep your body from becoming catabolic. But I just take a couple amino acid tablets when I get up.
Ron Paul Nuthugger
I think this topic will forever be argued but I personally know what AM cardio can do. Back in August 2004 when I found this site and began reading up and started training. I did my cardio in the AM and weights in PM. I went from around 258lbs to 196lbs..I just know for me it works.
***No source checks!!!***
AR's Diet Pimp! ~HOF~
There are a few factors to consider here. I don't think you need to worry about your body dipping into dietary protein or LBM for energy if:
> intensity is kept relatively low when doing cardio in a fasted state
> you aren't running a severe calorie restricted diet (i'm talking < 1300-ish calories/day)
> your body has adequate fat stores and has no 'need' to use protein/LBM for energy
If you want to rest easy, go with some BCAA's about 15 mins before fasted cardio, and immediately after unless you have your first meal at that time.
Pissing Excellence!
usually about 25-35 minutes.
Pissing Excellence!
damn P, that is an awesome transformation! i am doing it for the first time and loving it!
Pissing Excellence!
thanks GB. i am looking into getting some purple wraath for that reason. i have a protein shake immediately after, 30g whey protein and a banana. first meal about 20 min after that. and yes, my body has plenty of fat to feed off of!
AR's Diet Pimp! ~HOF~
I think you'll be fine. Take note of your energy levels and strength throughout the weeks, as well as your appearance. This will give you a true indication on what's happening with your body.
Purple Wraath is awesome - it's what I used while running my IF diet and training after a 16 hour fast - and I definitely lost no LBM, strength was through the roof in fact. I'd consider complex carbs in that post-cardio meal, vs. the banana.
Pissing Excellence!
well i usually have some sweet potato hash in the mornings with my eggs. i am not using any oats/grains or touching any dairy products. energy level is thru the roof!
~Knowledgeable Female Extraordinaire~
Fasted cardio sure helped me. Low intensity for 25 minutes.
Put on my shoes and went straight out the door.
Life is too short, so kiss slowly, laugh insanely, love truly and forgive quickly.Author Unknown
New Member
FWIW- we do fasted cario in the Army a LOT. There's no way you won't lose weight. Without proper supporting nutrition there MAY be some LBM loss, but if you keep lean protein and amino acids in proper balance you'll be fine, I think.
I've tried doing cardio after weight training sessions and simply could not gain any mass or strength. Stayed fairly lean but there was no forward progress.
Anabolic Member
Hey bro that's awesome stats. What was your body fat before and after? And how long did it take?
New Member
Cardio helps much in every regards and have the much better one affects on the health and fitness...
I think that if some one really wants to have the best workout than he/she will really got the amazing results....
Ron Paul Nuthugger
I honestly couldn't tell you. This was done August 2004-March 2005...I think I was 209 in March and as I kept going my lowest was 196 then slowly got my weight to around 210 as I continued to learn how to train. I went from 213 to 227 in 2007 and around 2008 pretty much started fading and now I am just trying to get back into it. Just got in from training actually.
***No source checks!!!***
Pissing Excellence!
glad to hear that you are back at it!
AR's Diet Pimp! ~HOF~
Great job bro!!!
Ron Paul Nuthugger
Yeah, this was my first week back and it's tough. I disgust myself to be honest but i'm fighting through it, this needs to become my lifestyle again as it once was. I will never be a bodybuilder and actually have no desire to be. I just want to be fit and feel good. Feeling good physically also helps us feel good mentally. It's also important to stay positive and be around positive people and this board use to really shine at that. I don't know I just don't get the same vibes anymore then again it could be me in this disgusting state? haha
***No source checks!!!***
Anabolic Member
Yeah your definatly right bro. im injured at the moment and cant do any upper body. When i first got the injury I kept training through it because i didnt want to stop training and lose any size, training/dieting is my life... anyway eventually i had to stop because it was to painfull. I stopped going to the gym all together got really depressed lost about 20lbs got a little belly. Now im still injured and cant train any upper body but i still go to the gym 5 days a week and just train legs, abs and cardio. Iv never felt better, im not depressed anymore in a happy state of mind! i still miss the size but i know il build back upto it when im better. So as you said "Feeling good physically also helps us feel good mentally" is very very true...
Goodluck anyway
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