sleep deprivation

I'm about as mentally sharp right now as a hammer, so please forgive gratuitous errors. I recently returned from France (great fun!) and have been running a sleep deficit. The time change, the long travel time, and two weeks of limited sleep have all taken their toll on me.

I've been curious about sleep deprivation for a couple of years. I've noticed that cramming for a test is a sure way to failure, but anxious insomnia has had little effect on physical activity. When I first started cycle racing I came across an article at pezcycling that caught my interest. In it Dr. Stephen Cheung describes military studies on sleep deprivation and performance.

The military is a perfect laboratory for this kind of research. Soldiers are routinely subjected to strenuous mock combat exercises for days at a time. During these exercises doctors and officers can monitor decision making ability and physical performance. Dr Cheung summarizes the results well by noting that while sleep deprivation affects both judgement and physical performance, dedicated training can minimize the losses. This type of training shows similar benefits to ultra endurance athletes. I don't think they need it though. Nothing can stop a century runner!

I found that medical papers on the subject are somewhat fascinating, but less practical. It seems intuitive that prolonged wakefulness leads to death in lab animals. Also medical tests on humans usually involve stationary people with acoustic stimulation. This is hardly a real life test. Records held in sleep deprivation are also staged for limited activity to increase wakefulness. Although I find it amazing that the record is for 11 days of constant consciousness. Most of the knowledge about sleep deprivation is over significant amounts of time and the concept of a "sleep debt" is highly debated. I guess you can't or don't have to make up for lost sleep.

I also have some friends that experiment with their sleep cycles. I don't know much about it, but its something I want to investigate further.

All of this leads to the fundamental question, why do we sleep? In the papers and articles I've read sleep seems to do quite a lot of good things for us. Sleep does things like refresh our ability to think and help our cells stay healthy. I know from my own work that coupled systems often have no single solution.

I'm only recovering from two days of almost total wakefulness. I did sleep for about an hour on the first plane. Also the 4 hour mark seems to be the critical amount in medical tests. So my two weeks of 5 hours a night should be just fine although I don't plan on making a habit of it. I value my sleep. Also the time change of 10 hours probably has something to do with my sleep habits and recovery time. So I guess my jet lag is just that. We'll see if I feel any smarter tomorrow!