It seemed straightforward enough: get up earlier to make use of the "best part of the day" and, hopefully, become more productive and energised.

I know that if there is one thing that demonstrates you are not the boss of your own body, it is sleep. Start messing with your circadian cycle and before long ruthless neurotransmitters are making you drowsy. Still, endeavouring to wake up a few hours earlier didn't appear too ambitious.

Self-improvement guides on the web were bursting with tips on managing sleep - apparently life's winners are out of bed before the dawn chorus has uttered a note. I ignored other research that suggested early risers are stressed and more susceptible to illness.

My modest aim was to get up two hours earlier than usual, at 6am. Next morning, when the radio came on, I thought the presenter was part of a dream. Even as my brain groped around for reality, it was falling back to sleep. I forced myself up, but spent the rest of the morning in a stupor, drinking black coffee.

It got easier, or less terrible, as the week went on. I found the trick was to get up and do something - a walk through the park was ideal for clearing the mind and energising the body. Then I would start work. By 9am, I had often achieved what it would usually take a whole morning to do. I began to think the self-improvement gurus were right.

But the cracks were showing by week two. The problem was going to bed. After a busy day, I would fall asleep in the early evening and then find it difficult to drop off at bedtime. Nights out also upset the routine. I wasn't getting my eight hours. I was living in a permanent state of jet lag. Daytime naps became deep sleeps. My concentration was shot to pieces. By the fourth week I was sleeping late and my new life lay in tatters. But I like the idea of giving it another try - perhaps if I give up my social life or become a dairy farmer.