PROTEIN

Athletes need more protein because they put more stress on their bodies. The muscle growth and tissue repairs that accompany exercise require protein. And protein's amino acids are crucial to many physical processes involved in exercise. For example, some amino acids influence hormones and neurotransmitters that play a role in athletic fatigue and performance.  An athlete—or anyone else, for that matter—who doesn't eat enough high-quality protein will feel weak and lethargic and will be more susceptible to colds and other ailments.