To replace the glycogen stores in your body quickly and effectively, eat a snack that contains both protein and carbohydrates. This will provide both fast-acting and sustainable energy to your body. Try to eat a snack within two hours of exercising, but wait a minimum of 15 minutes after exercising before you eat.Bring a snack along to the gym with you, so you can eat as soon as your workout is over.o replace the glycogen stores in your body quickly and effectively, eat a snack that contains both protein and carbohydrates. This will provide both fast-acting and sustainable energy to your body. Try to eat a snack within two hours of exercising, but wait a minimum of 15 minutes after exercising before you eat.