HOW IMPORTANT IS SLEEP?
Now I don’t think it’s any secret that sleep is good for us, if you’re getting an adequate amount each night, you’d be spending at least a third of the life in bed. Although There is still a lot which we do not know about sleep we do know that this is a time when the brain processes, sorts and stores newly gathered information, it is where hormones and emotions are regulated, additional cellular repair takes place throughout all areas of the body and the list goes on… But how does sleep help you when it comes to strength, body composition and athletic performance?
Well firstly, lets dive into the different stages of sleep, so that you have a better understanding of sleep itself.
SLEEP STAGES
Hypnagogic Stage (*Stage 1)
This is also known as the period in which you transition from wakefulness to sleep the pattern of electrical activity in your brain changes once you close your eyes and change from relatively high frequency waves also known as ‘beta waves’ to lower frequency waves also known as ‘Alpha waves.’
Stage 1 NREM (*Stage 2)
Alpha waves are replaced by low frequency Theta waves; your heart rate Begins to noticeably decrease and your muscles also start to relax. you are easily waking up during this stage and this stage of sleep is typical of the 20 minute nap.
Stage 2 NREM (*Stage 3)
This is where something known as sleep spindles begin to occur on an EEG study this is characterised by one to two seconds long bursts of neural activity. you are still easily woken when in this stage of sleep.
Stage 3 NREM (*Stage 4)
This sleep stage is where you begin to become less responsive to external stimuli and thus you become harder to wake up.
Stage 4 NREM (*Stage 5)
When you reach this stage of sleep Delta waves will dominate your brain activity. it takes roughly half an hour to reach this stage of sleep from the time you begun stage 1. Due to the Delta waves now dominating your brain, you become even more difficult to wake. From this stage you actually begin cycling back up and through the earlier stages of sleep, however Instead of re entering this stage of sleep once you leave stage 4 (Stage 3 NREM) You instead enter Stage 6 sleep or REM sleep.
REM (*Stage 6)
Commonly known as active sleep, REM is when the brain is as active as when you’re awake during the day. It is characterised by the eyes moving whilst the rest of the body is paralysed, hence why it is also coined the rapid eye movement stage of sleep.
SOMETHING IMPORTANT TO KEEP IN MIND…
When it comes to sleep, there is still quite a bit of debate as to what the all the purposes of sleep are…if sleep was solely about conserving energy (which it’s not), then we would not experience a REM sleep stage, seeing as during this stage of sleep we actually expend as many calories as we would while awake.
HOW DOES SLEEP AFFECT TRAINING?
Like I mentioned at the beginning of this article; sleep plays a vital role when it comes to strengthening neural pathways within your brain, this plays a major role in reinforcing habits and new skills that you’ve learnt. Better neural pathways and better connections in short, will equate to an improved ability to execute various tasks… e.g. in a lifters instance; a squat, for example. The degree to which sleep is beneficial for strength, isn’t as great, when compared to its benefits toward improving body composition or athletic performance/endurance, although it is still worth being noted.
A 2018 review of several studies over five (5) different databases, found that sleep deprivation over multiple consecutive nights of, resulted in a notable reduction in maximal force output (thus strength) in multi-joint exercises. The same wasn’t noted for single joint auxiliary exercises, which leads me to believe that this has to do with the negative impact that sleep deprivation has on solidifying new neural pathways within the brain; therefore new skills. E.g. learning to squat under load or to make improvements to pre-existing technique.
HOW DOES SLEEP AFFECT BODY COMPOSITION?
When you sleep, hormones are regulated, in particular insulin sensitivity is heavily impacted by sleep quality and quantity overtime. Other hormones such as Ghrelin and leptin (which are responsible for satiety and hunger) are also influenced. So in short, better insulin sensitivity and better regulation of appetite positively influence your body composition, whether or not you’re in a dieting phase or not; by improving general health/wellbeing as well as nutrient partitioning (a term essentially referring to the way in which your body chooses which nutrients to store and which ones to oxidise or allocate for synthesising new tissue/body). Favourable nutrient partitioning is synonymous with storage of glucose for energy in the form of glycogen, storing less energy in the form of adipose tissue, prioritisation of energy used to synthesise new tissue and in general downregulation of metabolic efficiency (which equates to you having a higher energy expenditure). *During prolonged periods of dieting/food scarcity, you’ll typically notice an increase in metabolic efficiency.
A 2010 study by Arlet V. Nedeltcheva, looked at the influence of sleep on different groups of individuals and found that when comparing 5.5 hours sleep/night to 8.5 hours/night that individuals lost 55% less bodyfat over the course of their dedicated dieting period. Muscle retention was also observed and noted to be lower in the 5.5 hours’ sleep/night group.
How Does Sleep Improve Your Performance?
When it comes to sleep and athletic performance and endurance there are quite a few pieces of literature out there now which stress the importance of sleep. A 2015 study observed the serving accuracy of college varsity tennis players and found that serving accuracy improved by 14% when sleep was extended from roughly 7 hours per night to roughly 9 hours per night.
How Much Sleep Do You Need?
Now although there is going to be some variability in this the general recommendations seem to be anywhere from 7 to 10 hours of sleep a night… closer to the seven hour per night if you are an ‘average Joe’ just looking to improve your results and closer to 10 hours a night if you are an elite athlete, adolescent athlete or would just like to take your progress very seriously.
To Wrap Up!
So there you have it! Now I hope you take sleeping a little more seriously from here on out now. If you do have strength, body composition or athletic performance-related goals, then adequate sleep plays a pivotal role in helping you achieve to achieve them. Typically in most cases, the more sleep you can fit in, the better.
