Sleep

Of all the methods of recovery to help mitigate cumulative fatigue, sleep trumps them all. Lack of sleep will inevitably lead to a decrease in performance and an increase in cortisol, and a decrease in testosterone. Sub-optimal sleep also leads to fat gain and weight loss (in the form of muscle)! Most athletes generally need 8 hours of quality sleep/night; however, everyone is different, and some people do just fine with 6, while others need 10. You should sleep the appropriate amount to where you feel rested and able to train again; you will not always feel pumped to go to the gym.