To make the most of your exercise efforts, you’ll want to properly fuel your body. Consuming the proper foods at the proper times will boost your immune system rather than drain it, and build muscle rather than break it down.
Before exercise: Eat a small (100-200 calories) high-carb snack about an hour before exercise. Good picks: fruit, or bread with jam. Do drink at least 8 ounces of water before your workout.
During exercise: No need to eat unless your workout exceeds an hour; then, a small snack such as a power bar. Stay hydrated by drinking 6–8 ounces of water per 15 minutes, or a sports drink if you exercise more than an hour.
After exercise: Include protein to rebuild muscle, at a carb-to-protein ratio of 3:1 (eg: peanut butter and an apple; yogurt and fruit; turkey on whole wheat bread). And rehydrate within an hour with 16-24 ounces of water.