Today's Featured Article is the first of a two part series on the relationship between sleep and running performance. Next week's article will examine how much sleep you really need, as well as how to improve both the duration and quality of your sleep.
Getting adequate sleep is not just "a good idea". It is critical in giving body the opportunity to regenerate, repair itself and to adapt to the stresses of training. More importantly, research shows that adequate sleep enhances immune system and reduces probability of contracting serious diseases such as cancer and diabetes or experiencing a heart attack.
Yet, sleep is an often neglected aspect of running's training and recovery cycles. Many training programs pay no more than lip service to this topic.
What does research say about the effect of running on sleep and vice versa?
Research conclusively shows that runners (and other regular exercisers) regularly fall asleep faster, have deeper sleep and feel less tired and more alert during daytime than sedentary people. For example, a 1985 Australian study showed that fit runners spend 18% longer in deep sleep (also known as slow-wave or delta sleep) then sedentary people. Protein synthesis, cell growth and tissue repair occur primarily during deep sleep. A 1997 American study showed that sleep quality improves when people first take up running and that exercising longer than one hour further improves sleep quality.
What is the best time of the day to run to promote a good night's sleep?
Research on this matter is inconclusive. We know that running intensely for 20-30 minutes raises body temperature 2 degrees or more. It often takes 4-5 hours for your body temperature to cool back down to normal. Therefore, it makes intuitive sense that exercising in the evening could inhibit your ability to fall asleep and enter deep sleep, both of which are enhanced by cooler internal and external temperature. A 2003 study at the Fred Hutchinson Cancer Research Centre in Seattle showed that exercising women aged 50-75 who exercised 3.5 – 4 hours a week in the morning fell asleep earlier and experienced better quality sleep than their counterparts who were evening exercisers. However, other studies showed that the time of day one exercised had little effect on length and quality of sleep.
The bottom line? If you run in the evening and experience sleep-related difficulty, experiment with running earlier in the day.
Will sleeping poorly the night before a race negatively impact your race times?
For most runners, the answer is (thankfully) "no". Most research indicates that sleep loss that is not chronic in nature does not impair short term performance in running.
Apparently, the adrenaline rush of competition overrides the negative effects of non-chronic sleep deprivation.
My own experience mirrors these findings. I ran my best half-marathon ever on 4 hours sleep. I've run good workouts on 4 hours sleep or less. However, even short-term sleep loss impairs your ability to perform activities that require mental acuity and/or fine motor skill (jogglers take note).
How does chronic sleep affect running?
Research on runners suffering from medium term or chronic sleep deprivation indicates that on average, they feel poorly during races or tough workouts, take longer to recover from training and get sick more often. This comes as no surprise, as sleep loss impairs endocrine and immune systems, elevates levels of stress hormones and compromises the immune system.
Interestingly, research shows a wide variation in an individual person's susceptibility to the potential negative effects of sleep loss. Tera Moody, who suffers from chronic sleep deprivation, is was one of the best American women marathoners 5 years ago. In the non-running arena, both former American President Bill Clinton and Donald Trump thrive on 5 hours sleep or less. Certain individuals are exceptions to the rule and can thrive despite getting less than adequate sleep on a continuous basis.
Does sleeping poorly affect your running? Can you run well on little sleep?
© 2014 Savvy Runner Inc.
Bennett Cohen and Gail Gould are the Founders and Presidents of the International Association of Women Runners. For access to resources to help you reach your goals for running and racing, visit www.IAWR-Connect.com..