How Running Affects Sleep (and Vice Versa)
Adequate Regenerative Sleep is Critical for Good Running and Health
By Roy Stevenson
Dedicated distance runners leave no stone unturned in their eternal quest for improvement, showing discipline far beyond what one would expect from most recreational athletes. They slog long miles on sore legs in nasty weather, sprint around the track doing interval workouts, buy the best high tech running shoes, and drink protein laced sports drinks after training.
Despite this extraordinary dedication, most runners grossly neglect an aspect of training and recovery that would seem to be commonsense: sleep. Getting adequate sleep is one component of the training and recovery cycle that is indispensable. One of the fundamental rules of recovery is getting enough sleep to allow the body to repair itself. Yet, over half the people in westernized countries have difficulty sleeping at least a few nights each week, or have sleep disorders of varying severity.
Most running books written by the “experts” completely neglect to mention the restorative powers of sleep, or pay only lip service to its importance, with the standard banal “make an effort to get adequate sleep” comment. And none of the several dozen running books I examined based their superficial recommendations for sleep on any research.
Sleep is not just something that we should “make an effort” to do, but speeds our recovery from running workouts. And many medical research papers show that getting adequate sleep reduces our chances of contracting diseases like obesity, cancer, heart disease, heart attacks, high blood pressure, and diabetes, and prevents a general impairment of our immune system.
What then, does the research tell us about running and sleep? In particular, runners are curious as to whether running improves their sleep, and concerned about whether sleep loss affects their running performance? We’ll take a look at these questions and finish up by reviewing how much sleep we need and some bedtime tips on how to sleep better and deeper.
Does Running Improve Sleep Quality?
People who exercise claim they fall asleep faster, have deeper sleep, wake up less often, and feel less tired during the day. Although these claims are difficult to verify, scientists have shown that people who exercise regularly and intensely spend more time in stage 3 and 4 slow-wave sleep. A research paper by Trinder, for example, found that fit runners, who average 45 miles/week, spend 87 minutes in slow wave sleep, 13 minutes or 18% longer than deconditioned people.
Brassington concluded that physically active older men and women slept longer, took less time to fall asleep, and were more alert during the day than sedentary older people. Sherrill’s study of 722 adults showed that men and women who exercised regularly had fewer sleep disorders. G. Passoss in her presentation at the 2008 Annual Meeting of Associated Professional Sleep Societies stated that patients with chronic insomnia who did moderate aerobic exercise drifted off to sleep 54% faster than other groups, and slept 37% longer.
Several other studies show that when we first take up running, our sleep quality is improved, and that exercising longer than 1 hour further improves sleep quality. Shapiro’s study of army recruits found their sleep quality improved during 18 weeks of basic training, with most positive effects occurring in the first 9 weeks. A caveat here though; severe and prolonged exercise such as that experienced in ultrarunning and marathon events actually disrupts sleep.
What effects does exercise intensity have on sleep?
A few research papers discovered that higher intensity exercise that causes sweating promotes a better quality of sleep than low-intensity exercise. This is because sweating causes the body to cool rapidly, which bring us closer to the lower temperatures we experience during slow wave sleep. Thus the cooling effect transitions us into slow wave sleep quicker.
When is the best time of day to run to ensure good sleep?
There is debate over this issue. Running intensely for 20-30 minutes raises your body temperature at least 2 degrees. Doing this immediately before sleep will delay your transition to deeper sleep because it takes 4-5 hours to cool back down. For this reason, it’s recommended that you exercise no closer than 3-4 hours before bedtime, some coaches even saying 6 hours before. This is good advice when you consider that exercise scientists think that running too close to bedtime leaves the sympathetic nervous system stimulated for several hours, making it harder for us to get to sleep.
A study conducted by the Fred Hutchinson Cancer Research Center in Seattle found that an hour of walking every morning relieves many sleep problems in older women (50-75 years). The women averaging 3.5 to 4 hours a week of morning exercise got to sleep earlier and did not experience as many sleep problems, as the evening exercise group. Morning exercise appears to set our circadian rhythms to stay awake during the day, and causes sleepiness at night.
Where does all this research leave us? The overall message is clear. A comprehensive meta-analysis of sleep and exercise research by Kubitz concluded that exercisers fall asleep faster, and sleep longer and deeper than non-exercisers. As for whether you should work out in the morning, afternoon, or evening, you will need to find what works best for you by trial and error.
How Does Sleep Repair the Body? We sleep in 4 stages, alternating between non-rapid eye movement (NREM) and rapid eye movement (REM). Each sleep cycle takes about 90 minutes. The average adult sleeps about 7.5 hours, or five full cycles, with 20% of that time in REM. Anabolism (repair) takes place during the four stages of sleep shown below, but particularly in stages 3 and 4.
Does Sleep Loss Impair Running 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, concentration and cognitive performance. Social consequences of sleeplessness appear to be irritability and inability to enjoy family and social relationships. But what happens when we lose sleep the night before a race? Will this adversely affect our running performance?
Researchers of sleep deprivation have looked at its effects on VO2 max, treadmill running and walking to exhaustion, respiration levels, maximal heart rate and other parameters of endurance exercise. Generally, the data shows that sleep loss ranging from 4-60 hours does not impair performance in short term, unskilled endurance activities like running, rowing and swimming. The adrenalin rush of competition (aka “arousal”) appears to override any negative physical consequences of sleep deprivation.
But, there does appear to be great variability in individual response to sleep deprivation. Some people are highly susceptible to sleep loss, while others seem to be resistant to it. A study by Martin and associates highlighted this variability when they walked sleep-deprived subjects to exhaustion on a treadmill. Two sleep-deprived subjects actually increased their walking time to exhaustion, 4 showed no significant change, and 4 subjects showed a large decline in time to exhaustion! This is something you need to bear in mind if you anticipate running with little or no sleep. If you’re susceptible to sleep loss, expect to perform below your best.
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 distance runners is that it takes longer to recover from races due to elevated stress hormone levels. Several studies show that our stress hormones, catecholamine and cortisol, levels are increased with the combination of sleep deprivation and exercise.
Another concern is that our ability to dissipate heat may be affected by sleep loss. Dr. Michael Sawka at the U.S. Army Research and Development Center, Natick, Mass., believes that “sleep loss can depress the body’s thermoregulatory system by reducing our ability to sweat during exercise”—something of great concern to the endurance athlete.
Many studies have investigated the effects of sleep deprivation on non-endurance sports. It appears that sleep deprivation does impair sports that require high levels of motor skills and coordination. But these activities are of limited interest to runners unless you happen to do marathons while juggling or performing mathematical equations. So if you miss several hours’ sleep for a night or two before your race, your performance is not likely to be impacted unless you are particularly susceptible to sleep deprivation.
How Much Sleep Do We Need?
Adults need between 7.5 to 8 hours of sleep a night. Most of us average only 7 hours of sleep, with one third of us averaging 6 hours or less per night.
To Nap or Not to Nap
Another area of debate by scientists is the issue of napping. Should you take naps during the day or avoid them because they may keep you awake at night? One study found that 80% of people sleep worse after an afternoon nap, while only 20% sleep better. Most readers will know whether napping degrades your nighttime sleep or not.
A study by Waterhouse concluded that a post-lunch nap improves alertness and aspects of physical and mental performance following partial sleep loss, and thus may be of use to athletes who have lost sleep during training or before competition. But, if you must nap make sure you do this at the same time every day, and for no longer than one hour. Do not nap any later than 3 p.m.
Bedtime Tips—How to Sleep Well
Preparation for Sleep
· Maintain a regular bed and wake time schedule, including on weekends.
· Establish a regular, relaxing bedtime routine (e.g. reading in bed, relaxing in a hot bath 1-2 hours before bedtime, meditation, breathing exercises, etc).
· Skip watching the news before bedtime if you find that it causes you to feel uneasy or stress. Likewise avoid activities like watching TV, eating, planning or problem solving while in bed. We tend to fall asleep if our body is relaxed and our mind is not focused on anything exciting.
· Avoid caffeine and nicotine close to bedtime (some say from noon on). This includes coffee, tea, soft drinks, and chocolate.
· Avoid alcohol because it causes sleep disruption during the night.
· Avoid heavy meals close to bedtime.
· Exercise regularly, but avoid exercising heavily within 3 hours of bedtime.
Your Sleeping Environment
· Create an environment that encourages good sleep: dark room (use blackout shades), absolute quiet, cool comfortable temperature.
· Blue light, emitted from computers, televisions, digital clocks and DVD players interrupt your body clock, or circadian rhythms. Cover them at night.
Can’t Sleep?
· See your physician or sleep disorder specialist if you think you have a sleep disorder-there are clinics in Scotland that specialize in this.
· If you wake up, stay in bed, close your eyes and relax. If you still cannot sleep, read a book.
· Avoid oversleeping, as it causes shallow, disturbed sleep.
Good Bedding
A good mattress is essential for good sleep.
A German study in 2001 found that a medium-firm pillow significantly improves sleep. Your pillow must support your head without burying it.
Cover your nonallergenic foam pillow with a dust mite protective cover. Put your pillow into the dryer every few months to kill dust mites, and replace it every two years.
Light Therapy
People suffering from sleep deprivation have been found to respond well to full spectrum lights (10,000 lux fluorescent lights), for 30-minute sessions early in the morning. This helps them get to sleep earlier and stay asleep longer. Regular exposure to this light triggers the nighttime release of melatonin, a hormone that helps maintain your body’s internal clock, giving you that sleepy feeling in the evenings.
Conclusions
Perhaps it’s time you evaluated your sleep habits to see whether you are allowing yourself enough sleep for maximum running performance. Remember, the constant cycle of overload, followed by adaptation and recovery is what improves your running, week-by-week and month-by-month. It’s critical that you give yourself enough sleep to recover from your training and racing. For good sleep, you need at least 30 minutes of moderate aerobic exercise, five or more days each week, and running is a perfect mode for this.
Roy Stevenson has a master’s degree in exercise physiology and coaching from Ohio University. He teaches exercise science at Seattle University in Washington State and has coached hundreds of serious and recreational runners and triathletes in the Seattle area.
As a freelance writer, Roy has over 200 articles on running, triathlons, sports, fitness and health published in over forty regional, national and international magazines in the U.S.A, Canada, England, Scotland, Ireland, South Africa, Australia and New Zealand.To read some of Roy’s articles please go to his website at www.Roy-Stevenson.com
Formerly from New Zealand, Roy competed in NZ Championships on track, road, and cross-country. He held the NZ under-20 marathon record in 1974 when he ran his first marathon in 2:42:28.