I've been noticing more and more lately that I often feel tired through the day, sometimes even as early as midday. In addition to feeling tired I sometimes struggle to maintain concentration for small periods of time which can be seriously demotivating. It's the cerebral equivalent of wading through deep water (if that makes sense). Everything takes a lot of effort and is generally very slow. I've not measured this (I have no way of measuring it) but I wouldn't be surprised if my bug count increased significantly when I feel like this. Sorry colleagues. Not everything is doom and gloom though. At other times, admitted less frequently, I feel sharp as a tack, full of motivation and as awake as a very awake person. Lately I've been wondering if these lapses can be attributed to sleep. 

How much sleep do you need?

All the information I can find on this suggests that the amount of sleep required varies by age and by person. Typically kids will need more sleep. For adults it's entirely subjective. Jimmy may be able to function on six hours sleep a night whereas his mate Ted will need nine hours. On average the figures I've seen suggest that between seven and a half and nine hours per night is fairly normal.

Sleep deprivation

Doing a bit of reading there are some pretty serious problems associated with sleep deprivation. Increased difficulty concentrating, making decisions and carrying out mental tasks; decreased motivation, decreased reaction times and creativity, to name but a few. I'm not saying I suffer from this kind of thing, not by a long shot. However one article I read suggested you could be sleep deprived even if you feel sluggish in the afternoon or feel sleepy in warm rooms. That's me all over. I'm practically a slug most afternoons. 

Sleep debt

Sleep debt is the accumulated amount of extra time you need to sleep to make up for missed sleep. This article suggests that if you feel drowsy after a large meal or in a warm room then you have sleep debt. As you can imagine having sleep debt isn't an unusual occurrence. Who hasn't missed a few hours sleep here and there? Clearly the effects of sleep debt won't be as pronounced as sleep deprivation but it can still lead to some reduction in productivity, excessive drowsiness and apathy amongst other things. 

So how to you reduce your sleep debt? The simple answer is sleep more, however some would suggest that sleep debt isn't as easy to recover from as you might expect. You can't just miss five hours and make up five hours the next night, it must be done slowly in one to two hour increments.

What can I do about my drowsiness?

I have never worried about the amount of sleep I get. If I'm tired I'll go to bed early. If I feel particularly awake or I'm working on something I'm more likely to stay up later. This means I don't get a regular amount of sleep and I've no idea how many hours of sleep I am actually getting. So, I decided to start recording what time I go to bed, what time I get up and how I feel throughout the day. In addition I thought it would be interesting to vary the amount of sleep I get which would hopefully give some indication of how much sleep I actually need and also help work out if my tiredness through the day was due to lack of sleep. 

I'm hoping it'll be as easy as six hours sleep = zombie, seven and a half hours sleep = Super Alert Man.

Not scientific you say?

I'm ignoring some pretty important factors which can affect how awake you feel, purely because they are difficult to measure. Primarily there's not necessarily any correlation between the number of hours you spend in bed and the number of hours sleep you get. Then add to that things like stress, busyness, alcohol, noise (say snoring or road works) and the possibility that it can take up to a week to adjust to a new sleeping pattern then I've potentially got some pretty unreliable results. Oh well, I did say it wasn't scientific. You want science? Go somewhere else! I'm really just interested in getting a general idea of how I feel after different amounts of sleep.

Tips

I've picked up a few tips to improve the quality of sleep, some of which are pretty obvious, others not quite so much. Here are some of the most useful ones:

• Go to bed and get up at regular times
• Take naps if tired but not too close to your usual bed time otherwise it might interfere will you normal sleep pattern
• Wind down before going to sleep. E.g. Read a book or take a bath. Coding till one in the morning then trying to go straight to sleep is a recipe for disaster
• Cut down on caffeine, particularly in the late afternoon/evening
• Staying up late to "fit more in" is counter intuitive. You may get more done in the short term, but in the long term you'll suffer

Conclusion

In an effort to quantify how sleepy I was feeling through the day I gave myself a rating from one to five every day for about two months. One being the most alertest thing since alertness was invented and five being practically narcoleptic. I also recorded other things which I thought might be pertinent such as staying up late for whatever reason or getting up early. 

My results seem to indicate, I would say with about 61% confidence (50% of all statistics are made up on the spot), that about eight hours to eight and a half hours sleep is ideal for me. I can survive on less sleep but after two or more nights with less than eight hours sleep there was often a noticeable increase in my tiredness.

Fairly obviously on days when there had been more activity and usual, travelling for instance, I was more tired. Also on days when I didn't wind down before bed it took me noticeably longer to get to sleep and I generally felt worse the following day.

You could say that that my conclusions are pretty obvious, and you would have a fair point. But still it was an interesting exercise and I learned some useful stuff. Time for a well deserved nap I think.