If you're on our mailing list or follow Victory on social media (Facebook or Twitter), you'll know that over the past week or so we've been asking you to send us your questions about the Foundation layer of our Health & Performance Pyramid, which encompasses sleep, stress, hydration and nutrition. It's been really interesting to read all the questions we've received, and I'm hoping the next few blog posts will start to answer them... this time, I'm focusing on sleep.
Why do we need sleep? Well, we tend to think of sleeping as being a period when the brain and body are in "idle mode", but research is increasingly showing that this just isn't the case. In fact, it's a period when we actively process our day, store memories, grow muscle, repair tissue and synthesize hormones.
What happens if we don't get enough sleep? I'm sure you know how you feel after a poor night's sleep. You tend to feel groggy and slow. You make mistakes at work. Your coordination is affected, you become less agile and your anticipation and reaction times become slower (hence the signs on the motorway which remind you not to drive when tired). Multiple that by lots of nights though, and it can become a real health risk, with studies showing correlation between chronic sleep deprivation and increased risk of obesity, diabetes and heart disease.
Does it matter when I sleep? Whether you're a night owl, or a lark, or a hummingbird (in the middle), the reason for it is partly genetic. In one study done at Stanford University, volunteers were given questionnaires to determine when they were most productive, and were then given blood tests to look at a particular gene called the clock gene which is known to affect biological rhythms. According to their questionnaires, owls preferred to do their activities and go to sleep between 10 and 44 minutes later than the larks; and there was a consistent difference in the makeup of their clock genes too. However, it isn't quite that simple, as in general, younger people tend towards the owl and older people are more likely to be larks.
What's the deal with sleep cycles? There are two main types of sleep: NREM (non-rapid eye movement) and REM (rapid eye movement) and we cycle through them in order. Over the three stages of NREM sleep (transition to sleep, light sleep and deep sleep), we gradually fall deeper and deeper asleep; and by the time we hit REM sleep (after around 70 minutes) we are ready to dream and are effectively paralyzed. A full sleep cycle takes around 90 minutes, and at the end of it, we return to light sleep again, which is the best time to wake. So if you want to wake up easily, think about your sleep in 90-minute chunks. If you want to sleep once a day, work back from the time you want to wake up, and try to go to sleep 7.5 hours (5 cycles) or 9 hours (6 cycles) before; or if you prefer to nap, try to arrange your sleeps in blocks of 90 minutes.
How much sleep do I need? This is the biggest question we hear, and the truth is that it varies from person to person so there's no one-size-fits-all solution. According to the National Sleep Foundation, most adults do best on around 7-9 hours of sleep per night, with teenagers needing up to 2 hours more, and over 65s an hour or so less. But this doesn't all have to be in one go: before the industrial revolution, many of our ancestors naturally gravitated towards a polyphasic sleeping pattern, where they would have two or more shorter sleeps during a 24 hour cycle. One such pattern is still quite commonly seen in the Mediterranean where afternoon siestas are the norm - or for other patterns, have a look at this website from the Polyphasic Society.
But how do I know if I'm getting enough? Probably the most important comment about sleep has to go to Jim Horne, from the Loughborough University Sleep Centre, who says "the amount of sleep we require is what we need not to be sleepy in the daytime.” However, if you're still not sure, popular psychologist Richard Wiseman has just written a fantastic book about sleep called Night School, and his website has a nice little self-test. And if you want to know how to sleep better... well, why not check out our Online Foundation Programme - or contact us to find out more about it?
