It’s important to understand how sleep impacts your performance in the gym. Have you ever felt that your exercise schedule or circuit training has not gone as well as you expected it to? Have you been feeling tired or has exhaustion come on earlier than you expected it to? There is a lot of published information available on the effect of sleep deprivation on athletic performance, although the results and conclusions of these studies are ambivalent and somewhat unclear.
Common Effects of Sleep Deprivation
The effects of sleep deprivation on athletic performance do not directly relate to your performance in the gym. Many studies, some of which are discussed below, have concluded that lack of sleep, or sleep disturbance, has a negative impact on the performance of athletes and other sportspersons, particularly on the night or two before competition. The effective word here is ‘performance’ which is not the same as training in the gym! However, there are some results which may directly be applied to gym training and exercise.
Many people are unaware of the importance of adequate sleep other than that alack of it makes them tired. Few are aware of the psychological or metabolic effects of sleep deprivation, or how it may affect their training performance so they get less benefit in the gym than they should. Here are a few effects of sleep deprivation not directly connected with your performance in the gym, but that could ultimately have an effect on fitness – and on your life. We shall explain later how it is possible for people to be fooled into believing they have over-trained.
Effect of Sleep Deprivation on Exercise Performance
A 1989 report by VanHelder and Radomski in Sports Med on the effect of sleep deprivation on exercise performance points to the effect of a lack of sleep on human metabolism. Various studies on deprivation of sleep of 30 to 72 hours show no effect on cardiovascular and respiratory responses to exercise or on the capability of individuals to carry out aerobic and anaerobic exercise and training. Also unaffected are muscle strength and electromechanical responses.
Time to exhaustion, however, is decreased by a lack of sleep. Although ratings of perceived exertion always increased during exercise in sleep-deprived (30 to 60 hours) subjects compared with normal sleep, this is not a reliable assessment of a subject’s ability to perform physical work. That is because the ratings of perceived exertion are dissociated from any cardiovascular changes in sleep deprivation.
Effect of Napping on Performance and Subjective Factors
Another study, published in the February 2019 issue of ACSM, was carried out on the effects of napping on the alertness, cognition and performance of 13 male karate athletes proficient to national level. The 13 were split between a reference normal night and a partial sleep-deprived night, and also a 30-minute nap and no-nap conditions. The results showed the nap to have no effect on physical performance or subjective fatigue in the reference (no deprivation) group, but to improve alertness and cognition.
The effect of the nap on the sleep-deprived group was to restore subjective alertness back to normal and also performance loss caused by the sleep loss. However, the nap had no effect on subjective fatigue. This tends to support the results of a previous study published in the December 2013 edition of the Journal of the American College of Sports Medicine (ACSM).
This study concluded that self-reported measures were negatively affected and not improved by napping. It looks like sleep deprivation could lead to an imbalance in the autonomic nervous system. This, in turn, could simulate symptoms of the overtraining syndrome, where the body is pushed beyond its ability to recover. The overtraining syndrome can in turn lead to insomnia and a vicious circle.
Being Fooled by an Autonomic Nervous System Imbalance
The autonomic nervous system is part of your nervous system that controls certain bodily functions that you do not consciously control yourself. This includes respiration rate and your heartbeat. Check out this 2015 Sports Med abstract published by NCBI which explains how it is possible for the autonomic nervous system imbalance to fool athletes by simulating symptoms of the overtraining syndrome. If an athlete believes he or she has overtrained, then that could be placed squarely at the feet of sleep deprivation. It may then be a matter of perception rather than a genuine loss of stamina or increased fatigue in the gym.
The evidence largely supports the view that good quality sleep is needed for maximum athletic performance; the more sleep the better. However, the view that lack of sleep has a significant effect on your performance while training in the gym is equivocal. It may be just your impression of inadequate performance and increased fatigue brought on by sleep deprivation. Further research is needed in order to improve our knowledge of how sleep impacts your performance in the gym – or your overall athletic performance.