Effects of diet on muscle glycogen stores and endurance.

[Aeries]

In this experiment, six subjects maintained normal caloric intake for three days but consumed most calories as lipid and five percent or less as carbohydrate (high fat diet). In the second condition (normal diet), the three day diet contained the recommended daily percentages of carbohydrate, lipid and protein. The fird diet (high carbohydrate diet) provided eighty two percent of the calories as carbohydrates. the glycogen content of quadriceps femoris muscle, determined from needle biopsy specimens, averaged 0.63g of glycogen per 100g wet muscle with the high fat diet, 1.75g for the normal diet and 3.75g for the igh carbohydrate diet.

endurance capacity during cycling varied considerably, depending on what each person consumed 3 days before the exercise test. With the normal diet, exercise lasted an average of 114 minutes, whereas endurance averaged only 57 minutes with the high fat diet. The high carbohydrate diet improved endurance performance by more than three times the endurance on the high fat diet. Interestingly, the point of fatigue coincided with the same low level of muscle glycogen under the three diet conditions. This experiment demostrated conclusively the importance of muscle glycogen for sustaining high intensity exercise lasting more than an hour. The research emphasized the important role played by nutrition in establishing appropriate energy reserves for long term exercise and strenuous training.

a carbohydrate deficient diet rapidly depletes muscle and liver glycogen and negatively affects performance in short term, anerobic exercise and prolonged high intensity earobic activities. These observations relate particularly to individuals who modify their diets by reducing carbohydrate intake below recommended levels. Reliance on starvation diets or other potentially harmful diets (e.g high fat, low carbohydrate diets, "liquid protein" diets, or water diets), proves counterproductive for weight control, exercise performance, optimal nutrition, and good health. Low carbohydrate diets make it difficult from an energy supply standpoint to participate regularly in vigorous, longer duration physical activities.

I wrote this in a way I hope many of you will be able to understand. If anyone has any further questions message me and I will get back to you asap.

[VegasPumped]

Altough I already knew that.
Great read, thank you.

Low carb will affect gym performance.

[Aeries]

cheers for the reply.

[-KEN-]

Very nice and i like it how its not 10 pages long

[mshenoy]

In this experiment, six subjects maintained normal caloric intake for three days but consumed most calories as lipid and five percent or less as carbohydrate (high fat diet). In the second condition (normal diet), the three day diet contained the recommended daily percentages of carbohydrate, lipid and protein. The fird diet (high carbohydrate diet) provided eighty two percent of the calories as carbohydrates. the glycogen content of quadriceps femoris muscle, determined from needle biopsy specimens, averaged 0.63g of glycogen per 100g wet muscle with the high fat diet, 1.75g for the normal diet and 3.75g for the igh carbohydrate diet.

endurance capacity during cycling varied considerably, depending on what each person consumed 3 days before the exercise test. With the normal diet, exercise lasted an average of 114 minutes, whereas endurance averaged only 57 minutes with the high fat diet. The high carbohydrate diet improved endurance performance by more than three times the endurance on the high fat diet. Interestingly, the point of fatigue coincided with the same low level of muscle glycogen under the three diet conditions. This experiment demostrated conclusively the importance of muscle glycogen for sustaining high intensity exercise lasting more than an hour. The research emphasized the important role played by nutrition in establishing appropriate energy reserves for long term exercise and strenuous training.

a carbohydrate deficient diet rapidly depletes muscle and liver glycogen and negatively affects performance in short term, anerobic exercise and prolonged high intensity earobic activities. These observations relate particularly to individuals who modify their diets by reducing carbohydrate intake below recommended levels. Reliance on starvation diets or other potentially harmful diets (e.g high fat, low carbohydrate diets, "liquid protein" diets, or water diets), proves counterproductive for weight control, exercise performance, optimal nutrition, and good health. Low carbohydrate diets make it difficult from an energy supply standpoint to participate regularly in vigorous, longer duration physical activities.

I wrote this in a way I hope many of you will be able to understand. If anyone has any further questions message me and I will get back to you asap.

I agree but to some extent. I have done some reading and wont say Iam an expert on this matter. but you should also consider the fact that Carbohydrate intake is converted to fat storage as Insulin is increased in blood and basic property of insulin is fat storage not fat synthesis. So isnt that a drawback. There have been a number of studies on high carb diet. Depending on the level of each individuals activity carb intake may vary and the body and the brain can very well survive on about 100 or so gms of carbs per day. For longer and extensive workouts you certainly need more carbs but again a lot of factors count into daily carb requirement. I am against carbs as a primary source of energy but again thats just me. I do not mean to dispute but its just my thought. Let me know what you think of it.

[KurtyJ99]

Three days eh....stopped reading there.

[Aeries]

I agree but to some extent. I have done some reading and wont say Iam an expert on this matter. but you should also consider the fact that Carbohydrate intake is converted to fat storage as Insulin is increased in blood and basic property of insulin is fat storage not fat synthesis. So isnt that a drawback. There have been a number of studies on high carb diet. Depending on the level of each individuals activity carb intake may vary and the body and the brain can very well survive on about 100 or so gms of carbs per day. For longer and extensive workouts you certainly need more carbs but again a lot of factors count into daily carb requirement. I am against carbs as a primary source of energy but again thats just me. I do not mean to dispute but its just my thought. Let me know what you think of it.

The trick to not gaining weight in fat is to consume what you need. If you consume too many carbohydrates then yes some will get converted to fat. But as there are 4 kcal to a gram of carbohydrates and 9 kcal to a gram of fat, you need more than twice the carbohydrates for fat conversion to take place. Thats over twice the excess energy that you need. So naturally you should regulate how much you consume against energy expenditure.

A carbohydrate-deficient diet quickly depletes muscle and liver glycogen and profoundly affects both all-out, maximal exercise capacity as well as the ability to sustain high intensity, endurance exercise. Spmeone who trains intensely should consume between 60 and 70 percent of their daily kcal as carbohydrates, predominantly in complex form. 8-10g per kg of bodyweight should be sufficient. For an event you could consume 80 percent for possibly better results but I wouldn't recommend it in the long term as you also need a sufficient amount of protein and fat.

So yes, consuming a large amount of carbohydrates like 80 percent over a longer period of time could be a drawback, but in the short term if you were about to compete in the ironman then you will likely get better results, otherwise stick to 60-70 percent of carbohydrates.

[Sash]

Err i don't see a link to the study, can you provide one? Not that i don't believe you, but i'd like to read the full study to see if it answers some questions i have - the biggest one being, why was 3 days chosen as the length of the study, wouldn't it take longer for the body to begin efficiently using fat as its primary energy source. The second question, what fatty acid profile did you use, e.g. how much sat/unsat fat. Cheers.