Getting adequate shut-eye is essential for optimal hormone production and the cellular functions of the body. When you don’t get enough sleep, your body responds with an increase in cortisol production and a reduction in testosterone and insulin-like growth factor-1 (IGF-1), which can collectively contribute to a highly catabolic state. Additionally, new studies have reported that sleep deprivation decreases the body’s level of protein synthesis and increases the activity of catabolic enzymes, favoring the loss of muscle mass and thus hindering the recovery that follows exercise-induced muscle damage. Making sure to get at least eight hours of sleep per night is a priority that should be at the top of every serious bodybuilder’s list.
REFERENCE: M. Dattilo et al., Med. Hypotheses, 2011, Aug;77(2):220–2.