Recovery Nutrition
Ellen Coleman, RD, MA, MPH © 2004

The restoration of muscle and liver glycogen stores is important for recovery following strenuous training. An adequate intake of carbohydrate and energy will optimize muscle glycogen storage during consecutive days of hard workouts.

Consuming carbohydrate shortly after exercise enhances the rate of muscle glycogen synthesis. Ivy et al (1) evaluated glycogen repletion following 2 hours of hard cycling exercise that depleted muscle glycogen. When 2 g of carbohydrate/kg was consumed immediately after exercise, muscle glycogen synthesis was 15.4 mmol/kg 2 hours after exercise. When the same carbohydrate feeding was delayed for 2 hours, muscle glycogen synthesis was cut by 66% to 5.0 mmol/kg 2 hours after exercise. By 4 hours after exercise, total muscle glycogen synthesis for the delayed feeding was still 45% less (13.2 mmol/kg) than for the feeding given immediately after exercise (24.0 mmol/kg).

Providing liquid or solid carbohydrate with equal carbohydrate contents after exercise produces similar rates of glycogen repletion. Reed et al (2) evaluated the effect of the carbohydrate form on glycogen repletion following exercise. The researchers provided 3 g of carbohydrate/kg in liquid or solid form following 2 hours of cycling exercise at 60% to 75% of VO2max. The subjects received half of the feeding immediately after exercise and half at 2 hours following exercise. There was no difference in muscle glycogen storage rates between the liquid and solid feedings at 2 hours postexercise or at 4 hours postexercise.

Delaying carbohydrate intake after exercise may reduce muscle glycogen storage and impair recovery. Rapid repletion of muscle glycogen is beneficial for athletes who train hard several times per day (they get the most out of their second workout) and crucial for athletes in events like the Tour de France (they don't have 24 hours to replenish muscle glycogen stores).

Athletes who exercise hard for >90 minutes daily should consume 1.5 g of carbohydrate/kg immediately after exercise, followed by an additional 1.5 g of carbohydrate/kg feeding 2 hours later (3). Athletes who are not hungry right after exercising can consume a high-carbohydrate drink (eg, sports drink, fruit juice, or a commercial high-carbohydrate beverage), which will also promote rehydration. The following feeding can be a high-carbohydrate meal.

Next: "Part 2"