Dr Gill Macleod at the Rood Lane Health Centre in East London suggests that the optimally functioning human being requires eight to 10 hours' sleep every night. Yet the average investment banker probably achieves nearer to six.
In a recent study, the 2000 Reuters Survey, it was shown that more than 55% of analysts work between 61 and 80 hours a week. The sad truth is that for these analysts and others, 12 hours in the office, three hours' travelling and a few hours in bed, leave little time for any of life's pleasures.
But while sacrificing sleep may seem easy at first, there are some hard truths in store later.
Inadequate sleep means exposure to a litany of problems. Some are mortally imperilling - tiredness is a major cause of road accidents. Others are more insidious.
Organs come under strain the heart, in particular, suffers. The sleep deprived age prematurely. Every investment bank houses 35-year-olds who look eligible for retirement.
According to James B Maas, author of the book Miracle Sleep Cure, sleep "fulfills an essential need of the body to restore energy for future performance." Increased blood supply to the muscles and a reduced metabolic rate enables the body to repair itself. It also helps to boost the immune system.
In The Promise of Sleep (Macmillan, 1999), veteran sleep researcher Dr William C Dement says that insufficient Rapid Eye Movement (REM) sleep leads to a "sleep debt", which must be repaid, hour for hour. Dement says that the average person is indebted to their sleep bank by 25 hours. REM sleep is crucial to memory, learning and new performance. Maas agrees: "Without it we would literally be lost, mentally."
Managing sleep involves managing this debt. Making up for lost sleep is crucial to curbing daytime tiredness. But compensation should be made in the form of early nights, not late mornings.
Sleeping late at the weekend only makes it worse when it comes to an early start on Monday, effectively leaving you jet-lagged.
As the Spanish and their Mediterranean counterparts have long known, sleep debt makes its presence felt most acutely in the early afternoon. Nevertheless, corporate Spain has been quick to disown the traditional nap - to its detriment.
Dr Dement says: "It seems nature definitely intended that adults should nap in the middle of the day." Maas claims that people who nap are substantially more alert than those who don't.
Richard Branson is propagating napping at Virgin. But investment banks seem unlikely to join in. "We didn't get to the top in the league tables for M&A and equity underwriting by sleeping in the afternoon," says a spokesman at Goldman Sachs.
Rules for managing sleep
- Sleep for at least eight hours every night. When you sleep less, compensate for lost sleep by going to bed early, as opposed to lying in late
- Sleep for continuous periods
- Establish a routine for going to sleep
- Exercise: this releases endorphins, which will help you to sleep better
- Cut down on coffee
- Don't drink alcohol within three hours of going to bed
- When daytime tiredness becomes irrepressible, try sleeping for a period of 10 to 15 minutes - but don't let your boss catch you
Finally, a study in 1998 conducted by Dr Chris Idzikowski of the Sleep Assessment and Advisory Service concluded that a better night's sleep is often possible simply by buying a new bed, rather than by taking sleeping pills.
The study found that people still using their worn-out and uncomfortable beds slept nearly one hour less than those who reposed on a comfortable bed.