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The Ultra-Marathoner’s Secret Weapon: Sleep

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Amy is a Registered Dietitian and avid Ultra-Marathon runner. She mixes her love of science, nutrition and athletics to enhance performance

If you strive to be successful in rigorous and challenging endurance races such as marathons or ultra-marathons, you are likely a bit of an obsessive-compulsive type. You like challenges, planning, and focusing on details to push yourself to meet your goals. Typically this means articulately drawing out training plans and scrutinizing every morsel you eat, but often one factor is left out of the equation. Adequate sleep can make or break your next high-level endurance competition.

There is no shortage of research linking adequate sleep to performance in endurance athletes. Understanding the implications of adequate sleep can be a game changer and motivate you to make necessary changes to improve your pre-race sleep.


3 Research-Driven Facts About Sleep and Athletic Performance

A scientific review published in the Clinical Journal of Sports Medicine evaluated the results from 113 separately published research articles. Here are the three main identified themes that the literature review holds in common.

  • Sleep deprivation is negatively associated with athletic performance.
  • Sleep extension appears to improve athletic performance.
  • De-synchronization of Circadian Rhythm (Disconnect of sleep-wake rhythm and light-darkness cycle) has no conclusive effect on endurance athletes.

These three themes have practical applications for endurance athletes and can explain how different sleeping patterns can have different effects on performance.


Sleep Deprivation Will Hurt Your Endurance Performance

This is due to several reasons. First, research shows that sleep deprivation has negative effects on mental performance. Endurance races are hugely mental, so a handicap in this area can be a big game changer.

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Second, tests of self-reported exhaustion show a strong correlation to sleep deprivation in endurance events. Time to exhaustion-is a commonly used phrase or parameter researchers use to evaluate the level of fatigue reported by athletes. When runners with sleep deprivation rate their ‘Time to exhaustion’, it shows their exhaustion comes much earlier in the race. There is a physiological explanation for this. Metabolic parameters and hormonal function play a large role in keeping fatigue at bay. In a sleep-deprived athlete, hormonal disturbances and metabolic changes occur. Primarily, insulin resistance increases and glucose tolerance decreases. These changes decrease the efficiency of glucose delivery to the muscle. When glucose is not efficiently delivered to muscles, fatigue sets in and hunger hormones become more prominent. This is a lose-lose cycle for an endurance athlete.

Sleeping More Pays Off

Getting adequate sleep can really pay off prior to an endurance event. According to the Mayo Clinic, adults require 7-9 hours of sleep daily for optimal function. As discussed above, sleep improves mental function. Keeping your wits about you and staying mentally strong during a race can be directly related to the sleep you had the night before. Additionally, your hormones function more optimally with good sleep. While insulin resistance and decreased glucose tolerance occur with sleep deprivation, the opposite is true with adequate sleep. Adequate sleep allows hormone function to be restored and glucose to be readily delivered to your muscle cells for energy.


De-Synchronization of Circadian Rhythm

If you’re a shift worker, night worker, or have difficulty sleeping at the same time every night, you may have a de-synchronized circadian rhythm. This can be defined as a disconnect of the sleep-wake rhythm and changes in the light-darkness cycle. This is different from sleep deprivation as the assumption is: you are getting adequate sleep, just at variable times daily. Don’t worry; this is not the end of your athletic career. With the rise of longer athletic events (24-hour races, 100-mile races etc.) athletes are faced with the challenge of performing all day and all night. While this brings up the problematic challenge of sleep deprivation, the transition and de-synchronization of the circadian rhythm appears to have little effect on athlete’s performance. Additionally, research suggests that the adaptability in shift or night workers may give them an edge in performing longer events at variable times of the day.

5-Ways to Decrease Pre-Race Jitters and Improve Sleep and Performance

Now that you know how important it is to sleep well before an endurance race or event, how do you set yourself up for success? Most athletes report nervousness and difficulty sleeping before big athletic events. These 5 tips can help you avoid the pre-race jitters and get more sleep before racing.

  • Don’t procrastinate on learning all the fine details of the race (course map, aid stations, supplies to bring, clothes to wear). If you are visiting a new destination for the race, go for a little walk on the actual course the day before. This can calm your mind about the terrain and provide a realistic expectation of what the race day course will look like.
  • Leave yourself some free time to visualize your preparations for the race. Visualize yourself getting dressed and ready in the morning, eating, and packing up to go. Considering all your preparations will give your mind a second level of reassurance.
  • Keep a paper and pencil by your bed. If you wake up in the night thinking of something you forgot, write it down. This can stop the repetitive thoughts from circulating in your brain and keeping you from going back to sleep.
  • Avoid or limit stimulants like coffee the day before the race. You may feel extra tired because your body is use to the caffeine, but the hormone-effect of nerves coupled with caffeine can be a bad combination for restfulness.
  • If you are having difficulty falling asleep, visualize success in your race. See yourself running your best race, fully rested moving fast and strong.


Carskadon M. A. (2005). Sleep and circadian rhythms in children and adolescents: relevance for athletic performance of young people. Clin. Sports Med. 24, 319–328. 10.1016/j.csm.2004.12.001

Reilly T, Edwards B. Altered sleep–wake cycles and physical performance in athletes. Physiol Behav. 2007;90(2–3):274–284. doi: 10.1016/j.physbeh.2006.09.017

VanHelder T, Radomski MW. Sleep deprivation and the effect on exercise performance. Sports Med. 1989;7:235–47.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

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