The Importance of Rest and Sleep

One thing that's a huge problem for many people is not getting the proper amount of rest and sleep.  For me, being a college student means late nights of studying and then having to get up early the next morning to study some more or for an early class.  Rest and sleep is especially important for those who are more active.  Your body requires more oxygen, uses and requires more energy, and must use this energy for tissue repair.  If you don't get enough sleep, this can actually cause you to gain weight.  This is because ghrelin, the hunger hormone, will increase while leptin, the satiety hormone, will decrease.  This will cause you to be hungrier during the day.  Lack of sleep can also affect insulin sensitivity and cause your fat cells to be more likely to store energy as fat.  Sleep is probably the most important part of recovery for your muscles.  Your muscles are actually growing when you're sleeping--not when you're at the gym! You're tearing muscle tissue when you are working out, and proper nutrients from the food you eat repair this tissue.  However, this tissue won't start being repaired until you are resting for a long period of time.  So if you don't get enough sleep, you won't allow your muscles adequate time to repair and grow.  Human growth hormone is also produced when you sleep.  This hormone plays an important role in growth, cell reproduction, and regeneration.  High levels of this hormone play a role in increasing metabolism.  Another hormone that is affected by sleep levels is cortisol.  Sleep helps lower levels of this catabolic hormone.  High levels can decrease your metabolism and cause muscle breakdown.  For these reasons, rest days are important to incorporate into your workout schedule.  As for the amount of sleep you should get, I think everyone knows that at least 8 hours is the general rule.  It can be different for everyone though.  In my opinion, quality is better than quantity so at least make sure that when you are sleeping, make sure it is a deep sleep with no interruptions!