Much is always made about the importance of sleep. Not only for general health and wellbeing but also for the prevention of disease and even obesity. In regards to weight training sleep is considered to be even more crucial. The three-sided paradigm of the successful athlete or serious trainee of the discipline of iron includes a rigorous regimen that involves plenty of heavy lifting, a diet that is rich in high quality macros and abundant in calories, and lastly and often considered the most important element: sleep. Plenty of sleep is what is suggested by anyone who knows anything to those who want to take his or her muscle-building or fat loss dreams to the next level.
It can safely be assumed that getting enough sleep is always a good idea as a general rule. Of that there is no doubt, but what are the real facts though? What really happens when we don’t get enough sleep? Is it the end of our muscle mass aquisition and the equivalent of slamming the proverbial brakes in reference to fat loss? That may be the case but like everything when it comes to what goes on inside of our body, there is more to the story.
First let’s look at insulin sensitivity. When insulin sensitivity is high the body is more likely to store energy in muscle cells where it is readily available to be used as energy during physical exercise. When insulin sensitivity is low the energy that we take in from foods is more likely to be stored as body fat and is not as readily available to the body as an energy source. When we don’t get enough sleep we can very quickly decrease insulin sensitivity. This is part of the correlation between obesity and lack of sleep. Fortunately all this can be corrected as easily as getting one good night’s sleep as insulin sensitivity then normalizes to baseline levels.
Another important hormonal consideration for those of who train seriously is testosterone. Testosterone is the king of all muscle-building hormones and also plays an important role in muscle retention during a fat loss phase and even indirectly to fat loss itself. When calories are under maintenance during fat loss then the risk of losing muscle is very high. Throw in a night of poor sleep and that will only serve to exacerbate the problem. Just like insulin sensitivity, a lack of sleep will quickly cause levels of testosterone to drop. Fortunately, also just like insulin sensitivity, all that is required to restore levels to normal is a good night of rest as levels will once again normalize to baseline.
Something else worth our concern is performance. With regards to muscle growth, hard training is not an easy task to undertake and in order to correctly stimulate the production of new proteins, one must train at a level that is extremely high. When fat loss is the main goal then physical performance is almost more so of precedence. The training becomes harder due to the lack of energy from the restricted caloric intake and there is often much more activity. Some of it is of the high intensity interval variety to further expediate fat utilization. Believe it or not, lack of sleep has not been shown to impair performance. It can safely be assumed that it does not enhance performance but getting a bad night sleep on occasion has no impact on the quality of your workout. The same is not true if the lack of sleep continues, however, as being in a state of exhaustion is not going to help matters in the gym whatsoever.
Another puzzling fact is that lack of sleep has the opposite effect on weight gain than you would think. It actually decreases it. There is a fairly large caveat and that is due to the fact that because you’re tired you are also less likely to move around as much and will use fewer calories in the process. This will negate any positive that you may have received from not sleeping well.
Chronic lack of sleep will most certainly negatively impact body composition, especially as ghrelin levels will rise increasing hunger and leptin levels will fall decreasing the utilization of body fat for energy. Your performance will certainly suffer and your lowered testosterone levels will decrease your muscle gains and also cause the loss of muscle tissue when calories are restricted. The lowered insulin sensitivity will lead to increased body fat as well and all of these factors add up to a disaster as far as physical fitness is concerned.
The only good news we can take from this is that short-term sleep deprivation will have little to no long term negative consequences. It is always advised that you get a good night sleep and these facts don’t change that message at all. Just like what was stated at the beginning of this piece, train hard, eat clean and sleep well and your fitness dreams are within your reach.