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Sleeping Like It's Our Job!
"Vitamin S" for Athletes
posted on November 24, 2003
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Sleep is vital to physical and mental performance. While sleeping, our bodies filter waste, rebuild muscle and bone, as well as process the experiences of the day from short-term memory into long-term memory. Sleep deficit diminishes peak power and time-to-exhaustion, it also compromises immune response, memory, and learning. By slowing glucose metabolism, sleep deficit depresses maximum energy levels and performance. (For coxswains and lightweight rowers, slowed glucose metabolism translates into 'harder to work off weight'.) Getting proper amounts, and the right kind, of sleep should be considered part of an athlete's training regimen.
We sleep in stages, and research shows that the full cycle -- not just total time -- is crucial.
There are two main stages, as measured by electroencephalograph (EEG) patterns: slow wave (deep sleep) and Rapid Eye Movement (REM) sleep, which is when we dream. During slow wave sleep, the pituitary gland secretes growth hormone, which rebuilds muscle cells broken down during physical workouts.
The first hour of sleep is slow-wave, followed by alternating periods of REM and slow-wave sleep. Beginning with periods of approximately 10 minutes, REM periods gradually lengthen, eventually extending to about an hour. Research on sleep subjects suggests that it is the full complement of REM sleep which truly makes us feel well-rested. Sleep subjects who are deliberately wakened at the onset of each REM cycle (thus prevented from dreaming), require more REM sleep later to catch up. They also show the effects of sleeplessness more: difficulty in concentrating, irritability, and -- in extreme cases -- hallucinations as the body desperately attempts to 'dream' even while physically awake. The last hour of sleep may be the most important of all. (Um, this may be difficult to reconcile with rowing being a sport of early morning practices and getting up early to travel to regattas.)
Animals who are predators dream more than animals who are prey. Dream sleep is (paradoxically) more difficult to wake from than 'deep' sleep (as anyone who has tried to wake someone who is having a nightmare has experienced). Thus, dream sleep is dangerous for prey animals, whose survival depends on being able to wake quickly. Evolution probably weeded out prey animals who dreamt too deeply. Dreaming is a luxury only animals at the top of their respective food chains can afford.
Caffeine disturbs sleep rhythms, not only when we want it to. The cycle of caffeine in the morning to jolt us into activity may contribute to a downward spiral, causing us to sleep less naturally that night, thus feel groggier and need even more caffeine to get going on subsequent mornings. Even confining caffeine intake to the early part of the day will affect sleep patterns. The metabolic half-life of caffeine ranges from 2.5 to 7 hours (meaning that, after 7 hours, half the caffeine is still present). It requires approximately 30 hours for 97% of it to clear the bloodstream; traces can remain in the body for up to a week. The coffee or tea you may have had in the morning, plus a soda at lunch or during the afternoon, will still be playing havoc with your sleep pattern for the next night, possibly two.
The best way to be bright-eyed and energetic in the morning is to get off the caffeine merry-go-round entirely. Not easy to do, but if you can, it is tremendously worth the shift. Fortunately, vitamin E (which is also good for increasing the contractive strength of muscle tissue, as well as improving the body's metabolism of oxygen and nutrients) seems to promote natural sleep. Athletes who must travel across time zones to competitions, vitamin E is your best friend. This is doubly true when traveling to compete at higher elevations.
Many coaches through the years have said -- and experience seems to bear this out -- that getting a good night's sleep two nights before a race is even more important than the sleep the night before. (I would be interested to hear from readers whether they know of any scientific studies which have measured this.) Play it safe, and get the sleep you need every night.
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| row2k author |
| Rob Colburn |
Rob Colburn coxed for St. Andrew's School and for Columbia University, and currently coxes for the masters rowing program at Carnegie Lake Rowing Association. He is still 3 lbs. under his college coxing weight.
Send Rob Email! Also, check out his new novel The Sultan's Helmsman |
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