How much sleep is enough sleep? And what about how Daylight Savings Time affects us?

Most people don’t really know how much sleep they should be getting per night. Studies are showing that getting the ‘right’ amount of sleep is super important to our overall health^{1, 2, 3, 5, 6, 7}. Many things can impact our sleeping routines; for example the change in the clocks (Sunday 25^th October if you’ve forgotten!), arguments or stressful situations, and having aches or pains. All of this can reduce the hours or quality of the sleep were getting.

At this time of the year, as we seem to ‘gain’ an hour, most people assume that means we get that extra hour as sleep. Research^1,2 shows that this does not make any difference to the amount of hours snoozing we get!

Actually, a study from 2009¹ showed that in the weeks after the clocks change, we actually get less sleep (on average 40 minutes a night!). As our body clocks are programmed to wake up at a certain ‘time’, internally we still wake up at this ‘time’ regardless of the changing of the clocks. The same study showed that as a consequence, people were having slightly more injuries at work, and therefore time off work¹. Who would have thought it!

But what does too little sleep actually do to our bodies? Reduced sleep over the long-term increases our appetite, which can lead to an increase in our body mass index³ (BMI). Furthermore, two studies from 2009 and 2007 showed that less sleep (for example Jet Lag or working shifts) can contribute to cardiac issues and diabetes^5,6.

An interesting fact shown in 2012⁷ was that too much sleep can also be detrimental to our health. This study found that too little or too much sleep could cause the development of chronic disease⁷! So how much sleep should we get per night?

The average adult in the UK needs 8 hours per night, but this is an average! The best way to tell if you’re getting enough (and that it’s good quality) is all about how you feel in the morning. When your alarm goes off, do you feel ready to attack the day, or do you want to hit the snooze button? If you’re the latter, you’re probably not getting either enough sleep, or enough QUALITY sleep.

What affects the quality of our sleep, I hear you ask? Have a think about what your night time routine is. Are you switching off your phone a few hours before bed? Or are you surfing Facebook or watching TV right before bed? We now know that the blue light from most devices (tablets and TV’s) are stimulating our brains, therefore as we sleep, our mind is more active. This distracts from processing the day’s events, and restoring and regenerating the body. So go to bed earlier, switch off the TV, have read of a (real) paper book, and chill out before bedtime. This will help you get a better quality and a more restful night’s sleep.

1. Barnes CM. & Wagner DT., (2009) Changing to Daylight Saving Time cuts into sleep and increases workplace injuries. Journal of Applied Psychology. 94 (5), 1305-1317
2. Harrison Y. (2013) The impact of Daylight Saving Time on sleep and related behaviour. Sleep Med Rev. Aug: 7(4): 285-292
3. Shahrad T., Lin L., Austin D. et al. (2004) Short sleep duration is associated with reduced leptin, elevated ghrelin and increased body mass index. PLoS Med 1(3): e62
4. Murphy PJ., Badia P., Myers BL. Et al (1994) Non-steroidal anti-inflammatory drugs affect normal sleep patterns in humans. Physiology and Behaviour. 55(6): 1063-1066
5. Knutson KL., Spiegel K., Penev P. et al. (2007) The metabolic consequences of sleep deprivation. Sleep Med Rev. 11(3): 163-178
6. Scheer FAJL., Hilton MF, Mantzoros CS. Et al (2009) Adverse metabolic and cardiovascular consequences of circadian misalignment. Proceedings of the National Academy of Sciences. 106(11): 4453-4458
7. Von Ruesten A., Weikert C., Fietze I. et al (2012) Association of sleep duration with chronic diseases in the European prospective investigation into cancer and nutrition (EPIC) – Potsdam Study. PLoS ONE 7(1):e30972