Some bodybuilders over-train, which can stress critical organ systems such as kidneys. EDIT: Rest/Recovery is necessary. Specifically, it's important not to in

Some bodybuilders over-train, which can stress critical organ systems such as kidneys. EDIT: Rest/Recovery is necessary. Specifically, it's important not to increase the amount of metabolic requirements you stress yourself with too rapidly before the body has time to adapt. The body can adapt to stress and become stronger (hormesis) but it takes time, rest, and nutrition.