If there's one thing people always overlook in their physical fitness programs, it's sleep. It's common to see guys (and gals) dial in their nutrition and training, only to sabotage their results by sleeping just four or five hours per night. This amounts to a huge waste of effort in the kitchen and the gym! If you think you can get away with poor sleeping habits, think again. Here are a few reasons why plenty of sleep is critical for reaching your goals.

Sleep is Anabolic

Most guys in the gym think that they grow WHILE they lift weights, but nothing could be further from the truth. Heavy resistance training actually breaks down your muscle tissue, which is part of the reason you become more fatigued as your workouts progress. It's only when you leave the gym, eat, and sleep that you finally grow.

In fact, deep sleep causes your body to release one of the most important hormones for muscle building - growth hormone. This is the stuff that makes babies grow at astonish rates during their first few years. That's why they sleep so much - to get bigger!

Proper sleep will also have indirect effects on your muscle-building endeavors. The better rested you are, the stronger and more energized you'll be in the gym. If you've ever done a hard workout with little sleep, you know how hard it is be at your best when you're tired.

Deprivation Makes You Fat

A common misconception among both fitness buffs and couch surfers is that insomnia and leanness are somehow related. Utter nonsense! Sleep deprivation has been proven time and again to increase insulin resistance - a common cause of obesity and diabetes.

When your body can't use insulin properly, it becomes alarmingly efficient at storing food as body fat. When this happens, you stay hungry after eating because those calories aren't actually available for energy. You become trapped in a horrible cycle of low energy, hunger, and fat gain.

On the flipside, getting a good night's sleep can actually increase your body's insulin sensitivity - a good thing for anyone interested in getting leaner. Your body can properly use carbs for energy when you do eat them, and it becomes more efficient at burning its fat stores when you don't.

Dealing with Life

Time and stress management are crucial aspects of physical fitness, but sleep deprivation will cause both to suffer. Most people believe they're too busy to sleep, but the reality is that being constantly tired is a serious drain on productivity. It's impossible to deal with work, school, family time, food prep, and training when you can hardly stay awake!

A lack of sleep also causes a rise in cortisol - the body's primary stress hormone. We need a little bit of cortisol, but a lot will cause the body to horde its fat stores like crazy. It'll also make it far more difficult to deal with your daily frustrations. If you want to be lean, muscular, and clear-headed - get some more sleep!