How much Sleep do you need?

I’ve been busy recently and the combination of working late and getting up earlier to fit in an early morning workout session has left me with less sleep than I have ever had before.

The question that has really been troubling me recently is how much sleep do you need?

and given my habit of burning the candle at both ends I really need an answer.

The issue of how much sleep do you need is particularly topical, given the recent publication by Cambridge University of a prospective sleep study where researchers followed nearly 10,000 people between the ages of 42 and 81 for nine and a half years, the aim of study was to investigate the relationship between sleep and heart health, one of the findings agree with the commonly held view that too much of anything can be bad for you because the study found that consistently having over 8 hours of sleep actually increases your relative risk of having a stroke.

Luckily for me there’s absolutely no chance of me having over eight hours a night so I’m pretty safe to this extent, but this doesn’t answer the question of how much sleep do I really need?

What I do know is that too little sleep it’s not too good for us either, in another research study (this time from the University of Chicago) students were limited to 4 hours of sleep for six consecutive days, they developed higher blood pressure, higher levels of stress hormones (particularly cortisol) and produced only half their expected antibody response when their immune system was challenged.

Particularly worrying was the fact that these sleep deprived subjects also developed signs of insulin resistance which is only a step away from diabetes, combine all of these physiological responses and we can understand why lack of sleep can predispose us to weight gain, diabetes heart disease and stroke.
Luckily in the Chicago study these physiological responses reversed when subjects ‘re-payed any sleep debt’ they had built up.

From personal experience lack of sleep makes me irritable, I loose concentration and I don’t function as well, but how much sleep is enough?
In the short term I want to avoid feeling tired and irritable, in the long term I also want to avoid any increased physiological risk that lack or too much sleep could cause.

Current consensus says that 7-9 hours of sleep is adequate for an adult under 64, with the elderly needing a little less, so given the current research a little under 8 hours is ideal and given the research from Cambridge University, I’m only going to sleep more than 8 hours unless if I’m repaying a sleep debt.

The golden rule is to listen too your body, if you are irritable and knackered your probably not getting enough down time so go to bed a little and get up a little later tomorrow, but remember too much of anything including sleep is not a good thing.