It is widely accepted that carbohydrates are a critical fuel source during exercise and also play a major role in promoting recovery after exercise. However, the importance of protein is less understood.
There is no doubt that protein ingestion helps athletes recover from exercise, but questions remain regarding the optimal amount, type and timing of protein needed in order to optimize training-induced adaptations in skeletal muscle.
How much protein do athletes need?
The current dietary reference intake (DRI) for protein for persons over 18 years of age, irrespective of physical activity status, is 0.8 g per kilogram of body weight per day (i.e., 80 g of protein for a 220-pound person).
However, many sports nutrition experts have concluded that protein requirements are higher for athletes (American College of Sports Medicine, American Dietetic Association, and Dietitians of Canada (2000). Joint Position Statement: Nutrition and athletic performance. Med. Sci. Sports Exerc. 32:2130-2145).
The additional protein may be needed in order to promote muscle adaptation during recovery from exercise in several ways:
- Aiding in the repair of exercise-induced damage to muscle fibers.
- Promoting training-induced adaptations in muscle fibers (e.g., synthesis of new proteins that are involved in energy production and/or force generation).
- Facilitating the replenishment of depleted energy stores.
The American College of Sports Medicine (ACSM), American Dietetic Association (ADA) and Dieticians of Canada (DC) recommend that (see reference above):
- Protein recommendations for endurance athletes are 1.2 to 1.4 g per kilogram of body weight per day, whereas those for resistance and strength-trained athletes may be as high as 1.6 to 1.7 g per kilogram of body weight per day.
These recommended protein intakes can generally be met through diet alone, without the use of protein or amino acid supplements, if energy intake is adequate to maintain body weight.