Sleep is not just something that athletes should "make an effort" to do—it speeds up recovery after workouts. And research shows that getting adequate sleep reduces the risk of serious health issues such as obesity, cancer, heart disease, heart attacks, high blood pressure and diabetes, and prevents a general impairment of our immune system.
Does endurance training improve sleep quality?
We sleep in four stages, alternating between non-rapid eye movement and rapid eye movement. Each sleep cycle takes about 90 minutes and has a different function. Anabolism (the repair of damaged muscle tissues) takes place mainly in stages 3 and 4, when we are in deep sleep and growth hormone activity is high, and physical processes such as heartbeat and breathing are slowed down.
People who exercise claim they fall asleep faster, have deeper sleep, wake up less often and feel less tired during the day. Scientists have shown that people who exercise regularly and intensely spend more time in stage 3 and 4 slow-wave sleep, a window of prime physical recuperation. A study published in Psychophysiology found that fit runners who average 45 miles per week spend 18 percent longer in stage 4 sleep than deconditioned people.
One study in the Journal of Aging and Physical Activity concluded that physically active older men and women slept longer and took less time to fall asleep. Several other studies show that when individuals first take up endurance training such as swimming, cycling or running, their sleep quality is improved, and that exercising longer than one hour further improves sleep quality.
When is the best time of day to train to ensure good sleep?There is much debate over this question. Running intensely for 20 to 30 minutes raises your body temperature at least 2 degrees. Doing this immediately before sleep will delay your transition to deeper sleep because it takes four to five hours to cool back down. For this reason, it's recommended that you exercise at least three or four hours before bedtime, and some coaches even say six hours before. Exercise scientists also think that running too close to bedtime leaves the sympathetic nervous system overstimulated for several hours, making sleep more difficult. But like most things in triathlon, trial and error will likely be the best way to find out what works for you as an athlete.
Does sleep loss impair triathlon performance?
Sleep loss has been shown to cause a cascade of undesirable effects ranging from impaired endocrine and immune system function to reductions in memory and concentration. Despite this—good news for triathletes continuous sleep loss ranging from four to 60 hours does not impair performance in short-term, low-coordination endurance activities such as running and swimming. The adrenaline rush of competition aka "arousal" overrides any negative physical consequences of sleep deprivation.
Additionally, sleep-deprived endurance athletes often complain that subjectively, their races feel much harder than usual—so don't expect to feel good during or after the race. Another disadvantage of sleep deprivation for endurance athletes is that it takes longer to recover from races due to elevated stress hormone levels: Several studies show that catecholamine and cortisol are increased with the combination of sleep deprivation and exercise.
How much sleep do we need?
Adults need between 7.5 and eight hours of sleep per night. Most Americans average only seven hours of sleep, with one-third averaging six hours or fewer per night.
Bedtime tips—how to sleep well
• Maintain a regular bed and wake time schedule, including on weekends.
• Establish a regular, relaxing bedtime routine, such as reading in bed, relaxing in a hot bath one to two hours before bedtime, meditation or breathing exercises.
• Skip watching the news before bedtime if you find that it causes you to feel stressed. Likewise avoid activities such as eating, planning or problem solving while in bed.
People tend to fall asleep if their bodies are relaxed and their minds are not focused on anything stimulating.
• Avoid caffeine, nicotine and alcohol close to bedtime—some say avoid them anytime after noon. This includes coffee, tea, soft drinks and chocolate.
• Avoid heavy meals close to bedtime.
• Exercise regularly, but avoid exercising heavily within three hours of bedtime.
Perhaps it's time you evaluated your sleep habits to see whether you are allowing yourself enough sleep for maximum triathlon performance. Remember that the constant cycle of overload, followed by adaptation and recovery is what improves your training, week by week and month by month. It's critical that you give yourself enough sleep to recover from your training and racing.
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Roy Stevenson has written more than ZOO articles on running, triathlon training and sports and fitness published in more than 50 magazines in the U.S., Canada, England, Scotland, Ireland, South Africa, Australia and New Zealand.
source: Triathlete_Magazine_May2011
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