Sleep and Muscle Growth: Everything You Should Know In the internationally bestselling book Sleep Smarter, Shawn Stevenson explains that being awake is catabolic (breaks you down), and being asleep is anabolic (builds you up). Sleep is an elevated anabolic state, optimizing the skeletal, immune, and muscle systems’ rejuvenation and growth. Sleep balances your hormones, boosts your metabolism, keeps your immune […]