When you ask most people if sleep is important, the majority will confidently reply that it is. Despite this, in the 2012 Great British Sleep Survey, the average score for participants was 5.1 out of a possible 10, meaning most people were down on their recommended amount of sleep by almost 50%.
And it’s getting worse.
In another study in 2013, researchers found that a third of the population (33%) get by on five to six hours’ sleep a night compared to 27% in 2010, with the average Briton going to bed after 11pm. Not only that, but in the same study, they found that almost 8 million people were turning to alcohol in the hopes of it helping them to sleep.
So our sleep is getting worse, but how big of a deal is it?
When it comes to optimum health, it’s a REALLY big deal. Poor sleep can contribute to increased fat storage.
Ghrelin, the hunger hormone, is increased after shortened periods of sleep. Not only that, but leptin (the hormone that tells you to stop eating) levels drop too. That means that as well as wanting to eat more if you’re not getting enough sleep, you’ll also find it takes longer for you to feel full and to stop eating once you start.
In fact, according to a 2004 study, people who regularly sleep for less than six hours a day were almost 30% more likely to become obese than those who regularly sleep for seven to nine hours.
What about if you just eat ‘clean’ or ‘healthy’ foods? If you have willpower forged of iron, maybe you’ll be OK, but numerous studies show a correlation between a lack of sleep and increased cravings for high-fat and high-carbohydrate foods. The theory for this is that they stimulate the pleasure centres of the brain, which may offset some of the negative feelings associated with a lack of sleep.
The upshot of this is that if you’re coming up short on the sleep front, not only are you failing to recover as effectively as possible, you’re probably going to gain weight too.
But what about the recovery itself; how badly is that affected?
There are literally hundreds of studies, if not thousands, that show that a lack of sleep increases recovery time in all areas, from wound healing to DOMS. One key area that’s often overlooked, however, is the link between sleep and testosterone.
Whilst many people recognise on some level that a lack of sleep can lower your sex drive (“Not tonight honey, I’m tired”), very few realise the potential implications of this.
A study published in the Journal of Clinical Endocrinology & Metabolism in 2002 suggests that many men with sleep apnoea also have lowered testosterone levels. In the study, nearly half of the men who suffered from severe sleep apnoea also secreted abnormally low levels of testosterone during the night. Research on women at this point is scarce, but there is no reason to believe that their androgen levels would be impaired any differently.
Testosterone is the main androgen responsible for the recovery and adaptation of muscle to stress, typically that imposed during exercise. Lowered ‘T’ levels would therefore mean a slower recovery time, which would mean slower progress, which in turn would mean an increased likelihood of dropout for those trying to get in better shape. The worst case scenario may even mean that minimal levels of testosterone are insufficient to allow any adaptation and that exercise is therefore actually causing more problems than it fixes.
And all of the above don’t even account for the serious health problems we know to be affected by a lack of sleep:
- Heart disease
- Heart attack
- Irregular heartbeat
- High blood pressure
So what can we do?
The following are the top five tips for improving your sleep and therefore your recovery time:
- Get to bed before 10pm. Our circadian rhythms (our biological clocks that determine when we wake and when we sleep) operate in fairly strict 24-hour cycles. Assuming a typical exposure to light throughout the day, most people’s bodies will be prepared for sleep between 9–10pm. Delaying going to bed will interfere with the timing of our biological clocks and begin to cause ongoing issues with our natural sleep patterns.
- Minimise your exposure to light after 8pm. Whilst this is harder during the summer months, dark curtains or blackout blinds can really help. Also limit your use of light-emitting electrical devices such as mobile phones, tablets and laptops, as the blue light they emit can affect sleep quality.
- Create a sequence of pre-bed habits. Just like Pavlov’s dogs, we are creatures of habit. Therefore, doing the same or similar things every night before we go to bed helps our bodies to prepare for sleep.
- Get out in the sun during the day. Vitamin D, also known as the sunshine vitamin, is produced by our bodies in response to sunlight. Low levels of vitamin D are associated not only with poor sleep, but also daytime sleepiness or fatigue. If for whatever reason you can’t get out in the sun, consider chatting to your GP or healthcare practitioner about supplementing with vitamin D. Just remember though, it’s a daytime vitamin, so you shouldn’t be taking it in the late afternoon or evening.
- Keep your bedroom as cool as possible. Whilst our lifestyles have evolved significantly from our Palaeolithic days, our needs have not. By keeping our rooms cold, we help to trigger certain hibernation-like responses that help our sleep.
One final point to note is that most of what’s been covered above is concerned primarily with sleep quantity. If you’re regularly getting at least seven hours of sleep a night and still don’t feel great, then sleep quality might be your issue. Assuming you’ve implemented the five tips above and have still not seen any improvement, this is something you may want to discuss with your GP, as there are numerous physiological as well as psychological factors that can affect how well you sleep.