How Does Your Diet Affect Your Recovery?

I am interested in learning more about the interaction between diet and recovery from either training or racing. Specifically, I would like to know how important consuming carbohydrates is compared to fat intake.
Thanks, David

Dear David,
Thanks for the interesting question. Early studies on post-exercise glycogen re-synthesis suggested that the optimum amount of carbohydrate to consume after exercise is about 1 g/kg body weight, beginning immediately after exercise and continuing at two-hour intervals until the next meal.

Carbohydrates that stimulate a large insulin response, as a consequence of increased blood glucose concentration (high glycemic index carbohydrates), are preferable to those that evoke only a low glycemic response. When the recovery period lasts two to three days rather than a day or less, the nature of the carbohydrate is not as important as the amount of carbohydrate.

When the recovery period is only 24 hours, the amount of carbohydrate consumed must be about 9—10 g/kg body mass in order to replace glycogen stores. Carbohydrate can be provided in liquid or solid form during the first five hours of recovery with equal benefit.

Although there is good evidence to support the recommendation that a high-carbohydrate diet during the 24 hours following prolonged heavy exercise will restore muscle glycogen to normal values, there is relatively less information on whether or not exercise capacity is restored when these dietary recommendations are implemented. Nevertheless, there are at least two running studies which show that eating a high-carbohydrate diet (9-10 g/kg body weight) following prolonged heavy exercise restores exercise capacity during continuous sub-maximal running (1) and following prolonged intermittent high-intensity running (2). Eating the high-carbohydrate recovery diet not only restored endurance capacity during the intermittent high-intensity exercise but also improved on the previous day’s performance.

During prolonged exercise, intramuscular triglycerides appear to contribute to fat metabolism and may even make up for a shortfall in the delivery of fatty acids from fat (adipose) tissue to muscle. However, not all authors agree that intramuscular triglycerides play an active role as substrate for energy production during prolonged exercise. For example, Kiens and Richter (3) reported that, whereas intramuscular triglycerides were not used during prolonged exercise, they were used during recovery, contributing to energy production while muscle glycogen re-synthesis progressed to completion.

REFERENCES
1. Fallowfield, J. and Williams, C. (1993). Carbohydrate intake and recovery from prolonged exercise. Int J Sports Med, 3, 150-164.
2. Nicholas, C., Green, P., Hawkins, R. and Williams, C. (1997). Int J Sports Med, 7, 251-60.
3. Kiens, B. and Richter, E. (1998). Utilization of skeletal muscle triacylglycerol during post-exercise recovery in humans. Am J Physiol, 275, E332-7.

FILED UNDER: Features / Nutrition TAGS: carbohydrate / eating / exercise / fat / food / glucose / glycemic-response / insulin / Race / Racing / recovery / Training

Paul Moore

Paul Moore is the Online Editor for Triathlete Europe. When not glued to a computer he can be found writing books - most recently Ultimate Triathlon: A complete training guide for long-distance triathletes which you can buy on Amazon

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