Sleep
Getting at least eight hours of uninterrupted sleep each night is crucial to keeping your body healthy and legs happy. Just as important as what happens to your body when you sleep is what happens to your body when you don't sleep.
Sleep deprivation alters your body's cortisol, testosterone, human growth hormone and insulin levels, as well as weakens the immune system and contributes to weight gain. REM sleep (rarely found in interrupted bouts of sleep) is when your body gets to work and repairs the damage that is done to it during the day.
During the slow-wave stage of sleep, human growth hormone is released by the pituitary gland. This stimulates tissue repair and allows your body to heal damaged muscles. Without sleep, you increase your chance of injury as the miles begin to add up without proper recovery.
Don't rely on your weekends to catch up on sleep; getting six hours of sleep each night during the week and 10 on weekends isn't enough. Establish a routine and stick to it throughout the week, going to bed and waking up at the same time every day.
Take good care of your body and it will continue to reward you with consistent training and fast times.
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