LACKING SLEEP – How it impacts exercise and body composition

Posted on: Apr 27th, 2017 by The Physio Movement | Categories: Sports Medicine & Nutrition

Regular and quality sleep is an important part of a healthy life, but many find this a hard thing to come by, be it the perceived lack of time, a condition that disrupts sleep (sleep apnoea) or just high levels of anxiety and stress.

Diet and Sleep

A lack of sleep has been proven to cause an increased caloric intake and lower levels of physical activity with higher prevalence of cardiovascular disease, diabetes, weight gain and all-cause mortality. The hours of sleep per night considered to be of most benefit is anywhere from 6-9 varying for the individual as factors such as age and gender. Not enough time spent on the pillows also has a detrimental impact on cognitive function, reaction times and motivation.

Diet and Exercise

The associated weight gain and prevalence of diabetes is due to sleep being an important factor for the release and regulation of growth hormone, cortisol, leptin and ghrelin. It also impairs glucose tolerance and insulin release. Leptin and ghrelin are hormones associated with appetite, inhibited levels of these hormones leads to increased hunger and less feeling of satiation, and the inhabitation of the body’s release of insulin is the main pathway to the cause of diabetes type 2

Whilst there is many studies completed on sleep and its direct impact on exercise, there is still a few grey areas because finding sound empirical evidence showing a direct impact of sleep on exercise is difficult as there are many confounding variables, such as double-blinding – the inability to have two groups unaware of what intervention they are receiving.

For those who are more interested in strength there has been some well documented hormonal changes with chronic lack of sleep causing a catabolic environment within the body, higher levels of cortisol and lower testosterone, leading to the theory that chronic lack of sleep will impede on protein synthesis, causing both impaired muscle growth and even an environment favoring muscle breakdown.

In regards to the more aerobic/anaerobic based exercises, the only consistent finding has been a significant impact of the time to exhaustion variable which has also been thought due to the catabolic environment that the body is under with lack of sleep disturbing the glycogen that is stored. Some of the other studies that have shown an impact between the sleep and non-sleep groups were more related to perceived exertion rather than any other physiological associated by-products of fatigue.

While there is a lot of grey area in how sleep directly affects performance itself, the indirect effects such as lowering of the immune function, increasing the likelihood of becoming sick, and the increased perception of effort and lower energy levels are the ways in where a lack of sleep affects those attempting to get consistent training

Adequate sleep can even be seen to be of more importance for those who are intensely training, which may seem like common sense, but as one begins to training at higher and higher intensities there is an increased susceptibility to get a Upper respiratory tract infection, couple this with chronic lack of sleep and it’s a recipe for a bout of the flu or a sore throat.

Whilst we don’t need science to tell us what most of us have known, that adequate sleep equals a happier and healthier you, having an understanding as to where that lack of motivation may have come from or that run down feeling, can lead you in the right direction to changing your habits to more beneficial ones.

Physiotherapy Townsville - The Physio Movement


     517 Flinders Street
Townsville City Qld 4810
     1300 TPM FIT or 4740 4516
Book Now
Book Now