EARLY to bed and early to rise makes a man healthy, wealthy and wise ...

acording to Benjamin Franklin. And that's it. I could stop right here and say no more.

A huge part of good health is sleep and plenty of it. End of.

However, you know me better than that, and true to form I will examine this crucial topic.

Back in the old days, and I am talking from prehistoric all the way up to our electric age, the vast majority of the population got plenty of sleep - they had hardly any practical option.

The cost and availability of night light was on a range from impractical to non-existent, and there was little in the way of social or practical activity that could be better carried out in the hours of darkness than during the daylight hours.

Now, too many people have too little rest for their bodies, and health suffers.

I am no sociologist, but I identify the disruption of classic sleep routines as being caused almost single-handedly by the television, and then absolutely locked in by the internet. And electric light has a primary role.

Indeed Benjamin Franklin and his 18th-Century electrical experiments with the kite are lurking at the back of our dependence on the bulb.

The availability of cheap, safe, easy-to-operate lighting that can turn a period of dark into an environment of useable light for working, reading, socialising, did just that.

Then television gave people a reason to stay up for longer and longer on dark evenings.

Remember Clem Ashby signing off at the end of the broadcasting evening for STV?

Now TV just continues through the night, and you can sit slumped, hopping a plethora of channels showing any old rubbish, into the small hours.

And most recently the internet has provided a platform for everyone - though it seems to be mostly the young - to stay awake, surfing and chatting on social media for as long as they want.

Add computer games to the mix. Such is the seductive effect of these that players - again mainly young - are hooked to their consoles and computers for hours on end to the exclusion of normal human interaction as well as missing hours of sleep.

Slumber is not an optional extra. If you miss out on this essential recovery period, you never get it back. It is a third of our daily cycle.

Human bodies are conditioned by millions of years of evolution to a certain rhythm that reflects the movement of sun and planet.

We exercise because that makes us fit for work and life.

We work as that produces the means of nourishing ourselves. We must nourish our- selves because that keeps us alive and ready to exercise.

And we sleep, because life is like a bank account and needs something put back in as well as something taken out. If you only, you will first get into overdraft, then go bust.

I am no killjoy. There is nothing wrong with a late night, even when there is an early start the next day.

Sitting with friends at a party or in your own home chatting, eating and drinking, singing, dancing, into the wee hours - all fun, and excellent for the soul.

But like anything else, too much of a good thing becomes a bad thing, and disruption of the pattern of sleep bears an increasing risk of damage and even disease.

Worse still is to become accustomed to getting too little of that necessary sleep.

Mrs Thatcher was said never to have more than four hours a night. If true, she ran a big risk - and I for one don't think that it was any badge of honour.

Just like the proverbial junior doctor trying to decide on drugs for a patient having had only three hours sleep in the last 36, letting a prime minister decide on war or peace after an all-nighter at the desk in Downing Street is not my idea of good government.

Whether we have a high-pressure job or not, cutting back on sleep is a false economy. Those who do are sluggish, irritable, and likely to be less productive at home and work.

A good kip is frankly a marvellous and utterly satisfying exercise. I use the word advisedly, as this column is all about how we exercise our bodies and minds to their best level.

Sleep is as much an exercise, or part of an exercise regime, as running or swimming.

So I am off for my afternoon siesta. Now, where are those Batman pyjamas?