Section 2 Glycogen depletion during weight training

The 3-Week Ketogenic Diet

Cyclical Ketogenic Diets Review

Get Instant Access

Having looked at glycogen levels under various conditions, we can now examine the rates of glycogen depletion during weight training and use those values to make estimations of how much training can and should be done for both the TKD and CKD.

Very few studies have examined glycogen depletion rates during weight training. One early study found a very low rate of glycogen depletion of about 2 mmol/kg/set during 20 sets of leg exercise (11). In contrast, two later studies both found glycogen depletion levels of approximately 7-7.5 mmol/kg/set (8,9). As the difference between these studies cannot be adequately explained, we will assume a glycogen depletion rate of 7.5 mmol/kg/set.

Examining the data of these two studies further, we can estimate glycogen utilization relative to how long each set lasts. At 70% of maximum weight, both studies found a glycogen depletion rate of roughly 1.3 mmol/kg/repetition or 0.35 mmol/kg/second of work performed (8,9). This makes it possible to estimate the amount of glycogen which is depleted for a set of lasting a given amount of time (table 2).

Summary

Glycogen levels in muscle vary depending on a number of factors including diet and training status. While there is a small amount of glycogen resynthesized following exercise even if no carbohydrates are consumed, the amount is insignificant and will not be able to sustain exercise performance for more than a few workouts.

Since high-intensity activity such as weight training can only use carbohydrate as fuel, a SKD will not be able to sustain high-intensity exercise performance. This mandates that carbohydrate be introduced into the SKD without disrupting the effects of ketosis. The two primary ways to introduce carbohydrate to the SKD are the CKD, which allows a period of high carbohydrate consumption lasting from 24-48 hours every week, or the TKD where the dieter consumes carbohydrates around training.

References Cited

1. Ivy J. Muscle glycogen synthesis before and after exercise. Sports Medicine (1991) 11: 6-19.

2. Phinney SD et. al. The human metabolic response to chronic ketosis without caloric restriction:

physical and biochemical adaptations. Metabolism (1983) 32: 757-768.

3. Phinney SD et. al. The human metabolic response to chronic ketosis without caloric restriction:

preservation of submaximal exercise capacity with reduced carbohydrate oxidation. Metabolism (1983) 32: 769-776.

4. Lemon PR and Mullin JP. Effect of initial muscle glycogen level on protein catabolism during exercise. J Appl Physiol (1980) 48: 624-629.

5. Zachweija JJ et. al. Influence of muscle glycogen depletion on the rate of resynthesis. Med Sci

Sports Exerc (1991) 23: 44-48.

6. Price TB et. al. Human muscle glycogen resynthesis after exercise: insulin-dependent and -

independent phases. J Appl Physiol (1994) 76: 104-111.

7. Yan Z et. al. Effect of low glycogen on glycogen synthase during and after exercise. Acta

Physiol Scand (1992) 145: 345-352.

8. Pascoe DD and Gladden LB. Muscle glycogen resynthesis after short term, high intensity exercise and resistance exercise. Sports Med (1996) 21: 98-118.

9. Robergs RA et. al. Muscle glycogenolysis during different intensities of weight-resistance exercise. J Appl Physiol (1991) 70: 1700-1706.

10. Conley M and Stone M. Carbohydrate ingestion/supplementation for resistance exercise and training. Sports Med (1996) 21: 7-17.

11. Tesch PA et. al. Muscle metabolism during intense, heavy resistance exercise. Eur J Appl

Physiol (1986) 55: 362-366.

Was this article helpful?

0 0
Weight Loss Enigma

Weight Loss Enigma

Finally Revealed The Revolutionary & Miraculous Weight Loss Secrets! Discover How to Command Those Unwanted Pounds To Take A Hike, So That You Can Get Into Shape & Lose Weight Easily Just Like You Dream Of In Just A Matter Of Weeks! You're About to Discover The Insider's Fat Burning Diet Tips to Easily Shed Off Those Extra Pounds And Obtain a Lovable Shape In No Time Flat!

Get My Free Ebook


Post a comment