Cardio articles....

[Pump_30]

For all you guys who love to do cardio on an empty stomach.....this is for you

http://www.bodybuilding.com/fun/topicoftheweek34.htm

[Giantz11]

You're kidding right, as if there aren't enough threads that address this.

[Giantz11]

Optimizing fat oxidation through exercise and diet.

Achten J, Jeukendrup AE.

School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom. [email protected]

Interventions aimed at increasing fat metabolism could potentially reduce the symptoms of metabolic diseases such as obesity and type 2 diabetes and may have tremendous clinical relevance. Hence, an understanding of the factors that increase or decrease fat oxidation is important. Exercise intensity and duration are important determinants of fat oxidation. Fat oxidation rates increase from low to moderate intensities and then decrease when the intensity becomes high. Maximal rates of fat oxidation have been shown to be reached at intensities between 59% and 64% of maximum oxygen consumption in trained individuals and between 47% and 52% of maximum oxygen consumption in a large sample of the general population. The mode of exercise can also affect fat oxidation, with fat oxidation being higher during running than cycling. Endurance training induces a multitude of adaptations that result in increased fat oxidation. The duration and intensity of exercise training required to induce changes in fat oxidation is currently unknown. Ingestion of carbohydrate in the hours before or on commencement of exercise reduces the rate of fat oxidation significantly compared with fasted conditions, whereas fasting longer than 6 h optimizes fat oxidation. Fat oxidation rates have been shown to decrease after ingestion of high-fat diets, partly as a result of decreased glycogen stores and partly because of adaptations at the muscle level.

[Giantz11]

Maximal fat oxidation during exercise in trained men.

Achten J, Jeukendrup AE.

School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

Fat oxidation increases from low to moderate exercise intensities and decreases from moderate to high exercise intensities. Recently, a protocol has been developed to determine the exercise intensity, which elicits maximal fat oxidation rates (Fat(max)). The main aim of the present study was to establish the reliability of the estimation of Fat(max) using this protocol (n = 10). An additional aim was to determine Fat(max) in a large group of endurance-trained individuals (n = 55). For the assessment of reliability, subjects performed three graded exercise tests to exhaustion on a cycle ergometer. Tests were performed after an overnight fast and diet and exercise regime on the day before all tests were similar. Fifty-five male subjects performed the graded exercise test on one occasion. The typical error (root mean square error and CV) for Fat(max) and Fat(min) was 0.23 and 0.33 l O(2) x min(-1) and 9.6 and 9.4 % respectively. Maximal fat oxidation rates of 0.52 +/- 0.15 g x min(-1) were reached at 62.5 +/- 9.8 % VO(2)max, while Fat(min) was located at 86.1 +/- 6.8 % VO(2)max. When the subjects were divided in two groups according to their VO(2)max, the large spread in Fat(max) and maximal fat oxidation rates remained present. The CV of the estimation of Fat(max) and Fa(min) is 9.0 - 9.5 %. In the present study the average intensity of maximal fat oxidation was located at 63 % VO(2)max. Even within a homogeneous group of subjects, there was a relatively large inter-individual variation in Fat(max) and the rate of maximal fat oxidation

[Giantz11]

Impact of exercise on adipose tissue metabolism in humans.

Arner P.

Department of Medicine, Karolinska Institute, Huddinge University Hospital, Sweden.

Mobilization of lipids from adipose tissue during prolonged exercise is of key importance for the supply of energy to the working muscle. During exercise lipid mobilization is mainly stimulated by increased catecholamine production leading to acceleration of the beta-adrenoceptor mediated lipolysis rate in fat cells. This causes breakdown of triglycerides in fat cells to glycerol and free fatty acids, which then are delivered to the blood stream. Decreased insulin production, enhanced adipose tissue blood flow and decreased reesterification of free fatty acids in fat cells contribute to the enhancement of lipid mobilization during strenuous and long-term light exercise. Several additional factors modulate the lipolytic response to exercise as well. Endurance training increases the lipolytic action of catecholamine whereas the opposite occurs during ageing. These alterations are at least in part mediated by changes in the function of the final step in lipolysis activation, the protein kinase-hormone sensitive lipase complex. There are also gender and regional differences in the lipolytic response to exercise. Women mobilize more lipids from the subcutaneous abdominal area than men, whereas a low rate of lipid mobilization from the peripheral subcutaneous areas is observed in either sex. In pathophysiological states, which are associated with catabolism such as fasting and insulin dependent diabetes, there is an enhanced lipolytic response to exercise, because of increased beta-adrenoceptor function.

[Giantz11]

The combined effects of exercise and food intake on adipose tissue and splanchnic metabolism.

Enevoldsen LH, Simonsen L, Macdonald IA, Bulow J.

Department of Clinical Physiology, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark.

Seven young, healthy male subjects were each studied in two separate experiments. (1) Subjects exercised for 60 min at 55% of peak oxygen consumption in the fasted state ending 30 min before a meal (60% of energy as carbohydrate, and 20% of energy as lipid and protein each) comprising 25% of the total daily energy intake, and were then studied for another 150 min postprandially during rest (E-->M). (2) One hour after a similar meal, subjects exercised for 60 min and were then studied for another 180 min postexercise during rest (M-->E). Regional adipose tissue and splanchnic tissue metabolism were measured by Fick's Principle. Food intake before exercise reduced whole-body lipid combustion during exercise to about 50% of the combustion rate found during exercise in the fasted state. The increase in subcutaneous, abdominal adipose tissue lipolysis during exercise was not influenced by preexercise food intake, while the fatty acid mobilization was increased by only 1.5-fold during postprandial exercise compared to a fourfold increase during exercise in the fasted state. During exercise, catecholamine concentrations increased similarly in the fasted and the postprandial state, while the insulin concentration was twofold higher postprandially. These results indicate that the increase in catecholamine concentrations during exercise is a more important determinant of the adipose tissue lipolytic rate than the decrease in insulin concentration. Furthermore, food intake either 30 min after or 1 h before exercise prevents the postexercise increase in adipose tissue glycerol and fatty acid release which normally takes place in fasting subjects at least up to 2.5 h postprandially. Postprandial exercise led to a faster increase in postprandial lipaemia. This could not be accounted for by changes in the regional splanchnic tissue or adipose tissue triacylglycerol metabolism. Exercise was able to increase hepatic glucose production irrespective of food intake before exercise. It is concluded that exercise performed in the fasted state shortly before a meal leads to a more favourable lipid metabolism during and after exercise than exercise performed shortly after a meal.

[Giantz11]

Effect of exercise training at different intensities on fat metabolism of obese men.

van Aggel-Leijssen DP, Saris WH, Wagenmakers AJ, Senden JM, van Baak MA.

Department of Human Biology, Nutrition, Toxicology, and Environmental Research Institute, Maastricht University, 6200 MD Maastricht, The Netherlands.

The present study investigated the effect of exercise training at different intensities on fat oxidation in obese men. Twenty-four healthy male obese subjects were randomly divided in either a low- [40% maximal oxygen consumption (VO(2 max))] or high-intensity exercise training program (70% VO(2 max)) for 12 wk, or a non-exercising control group. Before and after the intervention, measurements of fat metabolism at rest and during exercise were performed by using indirect calorimetry, [U-(13)C]palmitate, and [1,2-(13)C]acetate. Furthermore, body composition and maximal aerobic capacity were measured. Total fat oxidation did not change at rest in any group. During exercise, after low-intensity exercise training, fat oxidation was increased by 40% (P < 0.05) because of an increased non-plasma fatty acid oxidation (P < 0.05). High-intensity exercise training did not affect total fat oxidation during exercise. Changes in fat oxidation were not significantly different among groups. It was concluded that low-intensity exercise training in obese subjects seemed to increase fat oxidation during exercise but not at rest. No effect of high-intensity exercise training on fat oxidation could be shown.

[Giantz11]

Before posting some retarded BB.com article, please post some studies or your opinoin as to why AM cardio is bad.

[The Dynasty]

Owned.

[Pump_30]

Just food for thought Doctor numbnuts......

[Giantz11]

Don't get me wrong, there's always room for a little debate...However it seems as if everyday someone is trying to say that Morning Cardio is catabolic....Its just plain old stupid, and then there will be a 100 posts with people saying I thought morning cardio was good and no you say its bad. That is that both HIIT and LI cardio work, through different mechanism's. For HITT a nutrtional stategy also needs to be employed which is often over looked as well. If someone thinks that after being asleep for 8 hours they are extremly catabolic and muscle is literally wasting away they need to do a whole lot more reading, cause it take way longer than that.

[IronFreakX]

-Low intensity cardio does burn fatty acids....BUT.....total amount of calorie burned is not that much

-low intensity cardio is for the purely cosmetic bodybuilder(wanting nothing but looks)..and it works gr8 for them!!

-low intensity cardio does not eat muscle mass



-High intensity cardio burns alot more calories but will burn some protein with it

-high intensity is not for the bodybuilder but more for the strengh/powerliter/athlete type

high intesity , low intensity , E cardio , cardio after consuming carbs and pro are ALL good

its just that some people need different kinds of cardio....

depending on wut ur goals are choose the rite kind....

[Giantz11]

good point! Only thing I would say is that even though LI cardio is yes Low Intensity you are still elevating you rHR for 30-45 min, which is beneficial cardiovascular wise, not as much as higher intensity but certainly better than nothing.

[IronFreakX]

good point! Only thing I would say is that even though LI cardio is yes Low Intensity you are still elevating you rHR for 30-45 min, which is beneficial cardiovascular wise, not as much as higher intensity but certainly better than nothing.

elevating for 65-75%....which is not really that low.....

good for u guys(bodybuilders)...but i train for different things (strength , speed , endurance , fighting skills , atheltic abilities in general , pain tolerance and finally low bf% cuz if ur not gonna be huge @ least have a nice set of abs

[Giantz11]

No doubt.