One of the most underutilized methods of recovery and regeneration is adequate sleep. In this blog post I will discuss some of the key reasons a good night's sleep is critical for optimal physical condition and mental performance!
The key driver behind our sleeping pattern is an internally controlled pattern called a ‘Circadian Rhythm’.
The Circadian Rhythm is a 24 hour cycle that regulates our internal systems, highly influenced by external factors  - primarily daylight exposure - to allow our body to adapt as best as possible to the world around us. In relation to sleep all the external stimuli that surround us at almost any time of the day with the artificial lights in our homes and on our smartphones has been shown to have a negative effect on sleeping patterns. The primary way in which this artificial light reduces the quality of your sleep is by suppressing the production of melatonin - a hormone triggered by exposure to dark/light and critical to your ability to sleep well.
Negative effects of Poor Sleeping Habits
There are several negative outcomes associated with poor sleeping habits, below are just a few!
Inhibits Weight Loss
Lack of sleep can affect your body in many ways but I will start with one of the ways in which a lack of sleep can interfere with the good work that you may be doing in the gym.
A lack of adequate sleep is linked to obesity and weight gain and there a number of reasons behind this.
Studies have shown that those who suffer from chronic sleep deprivation have altered levels of ‘hunger hormones’ leptin and ghrelin - compared to those who have a regular and sufficient sleep cycle. 
‘Ghrelin’ is the hormone that makes you feel hungry and ‘Leptin’ is the hormone that makes you feel full. When sleep decreases your body compensates by increasing ghrelin levels and decreasing leptin levels - making you feel hungrier and making it harder for you to resist the cravings for extra food and therefore, extra calories.
Insufficient sleep is also linked to increased levels of cortisol - this can lead to craving of high sugar, high fat foods that are highly palatable and easy to overconsume. 
Recovery and Regeneration
During resistance exercise our muscles break down and the process through which they grow back and repair is what makes them stronger.
Lack of adequate sleep can interfere with this process and lead to inadequate recovery from your gym sessions - meaning that you are not getting the full benefits and growth that could be possible.
What is the point of committing to come to the gym 3 or more times a week to get stronger and leaner, if your habits outside the gym are inhibiting your progress?
You need sufficient and deep sleep to allow your body to produce enough growth hormone to repair and regenerate your muscles, cells and tissues. A chronic lack of sleep will affect your body in that you will not recover adequately and you will be fatigued. This will increase your risk of injury and slow down your physical progress - both in terms of losing body fat and getting stronger. 
Studies have shown that sleep is important and directly linked to better physical and mental performance on both a general and elite level.
A study of elite athletes noted that when their sleep was extended over a prolonged period - their athletic capacity improved both in terms of their consistency of skill execution and their overall markers of athleticism such as speed. 
In a study of over 2,500 older women - those who slept poorer exhibited weaker grip strength (a very important and reliable predictor of health in older age) and walked slower as they went about their day. 
Another study showed that lack of sleep affected the cognitive performance of the brain as much as intoxication from alcohol - a consideration if you are in a job that requires you to maintain consistent focus and concentration as a prerequisite such as a driver or an operator of heavy machinery. 
New motor pathways are forged during sleep - so depriving your body of the rest it needs is going to hold back your ability to learn new processes.
If you are learning a new skill such as a language in school, serving in tennis or a deadlift in the gym - if you do not give your body time to sleep and forge these new mental pathways or consolidate your memories, the learning process will be slower than with adequate amounts of sleep.
The second way in which sleep deprivation can stunt mental growth is through the inability to focus and concentrate during your active hours - if you are sleep deprived the cognitive performance of your brain suffers and you will not be able to process and internalise information as well as if you were in a well-rested and refreshed state.