Running and the Importance of Sleep

Original Editor - Kapil Narale

Top Contributors - Kapil Narale  

Introduction

It is essential to get an adequate amount of sleep every night for human health. This would equate to 6-8 hours of sleep. Accumulating this much daily sleep has restorative effects on the immune system, function of the endocrine system, and cognitive performance , thus recovery from daily physical activity and exercise. There are many important factors that are considered with good sleep health, including tiredness, sleep duration, sleep efficacy, sleep quality, and time to fall asleep (sleep latency). It is seen that poot sleep quality results in bad sleep. Restful and good sleep can help indicate a good sleep quality. Minimal tiredness the next day, a high sleep efficacy, and a low time to fall asleep can help indicate a restful sleep.

Sleep is also very important for athletes, as it plays an important role in physical, physiological, and cognitive performance. Sleep is essential for athletic and sport performance, which has a positive impact on illness, injury, metabolism, cognition, memory, learning, and mood. However, athletes are seen to obtain less rest due early rising times, possible injuries, and anxiety during heavy training periods and before competition. The restorative function of slow wave sleep ma help explain the benefits of sleep on performance, serving as a recovery from previous active hours. Less rest could also be caused by occupational, academic, social, and familial obligations.

It is seen that middle aged adults claim poorer sleep heath than younger adults, however younger adults experience a longer time to fall asleep, especially with the exposure to electronic devices before bedtime. The use of electronic devices, such as TVs, computers, tablets, and smartphones, can result in poor sleep quality, disturbed sleep, and a lower sleep duration. Further information on the effect of electronic devices can be found on the Blue light and the Effect on Sleep page.

Marathon Runners

In a study by Cook et al (2023), analysing a sample of marathon runners from the 2016 London marathon, generally the age group of 18-39, it was found that marathoners had sleep durations between 6-8 hours, had a time to fall asleep of less than 15 minutes, mostly remained asleep throughout the night, had a quality of sleep that was 'somewhat or very satisfying', and had no sleep-related medication use. The use of sleep tracking devices was uncommon, as was a high alcohol consumption (within 14 drinks per week, most had within 7 drinks per week). Most individuals also reported having within 2 caffeinated drinks per day. In addition, the majority of individuals claimed to use electronic devices within 1 hour of sleeping everyday.

It was seem that males reported a lower sleep duration than females, while females had a higher use of sleep-related medications.

There were significant differences noticed between young adult (18-39 years) and middle (40-64 years) age groups for many sleep health qualities. Middle aged adults had higher overall sleep problems, which seems to have been caused by a higher total sleep time duration, poor sleep satisfaction, and more issues remaining asleep throughout the night. In the middle-aged adults, it was noted that they may have increased stress or medical problems contributing to their disturbed sleep. Younger adults experienced a longer time to fall asleep, which may be a contribution of differing lifestyle factors such as the use of caffeine, alcohol, and technology such as electronic devices and sleep trackers.

Runners who completed the marathon with a slower pace than predicted had a significantly more disturbed or discontinuous sleep throughout the night. There was a significant difference in maintaining continual sleep between males and females, although females did experience more sleep related issues.

It is seen that marathoners who have a slower marathon finish time are associated with a longer time to fall asleep. It is also seen that marathoners with a shorter sleep duration and a more pronounced difficulty with sleep had a longer marathon completion time.

It is interesting to note that elite athletes, in general, experience poorer sleep quality and sleep duration due to times of the day for training, stress and anxiety related to competing, muscle soreness, caffeine use, and travel. Other factors such as nutritional status, environmental aspects, varying time-zones, and general stress, can all contribute to athletic performance, and therefore sleep.

It is noted that an increased strenuous training and competing in endurance events, such as marathon races, can lead to a high risk of infections such as an upper respiratory tract infection.

When considering marathon runners, or even ultramarathon runners, the longer the distance of the race, the more important it is to have an optimal sleep for an improved race performance.

Ultramarathon Runners

An ultramarathon would have a wide range of definitions, since it encompasses anything more than 42km or 6 hours.

In a study by Bianchi et al, comparing sleep of ultramarathoners before, during, and after the race days of a 200mile race, it was found that there was more importance put on sleep during and after the race periods. However, there was less than the 8 hours of recommended sleep prior to and after the race period. In another study by Milner et al, which explored sleep/wake cycles before, during, and after ultramarathon races lasting more than 161km. It was found that there was no sleep taken during these races. However races more than 322km, had more sessions of sleep with a longer duration per session. Thus it was seen that at distances shorter than 161km, consistent running proved more effective than taking sleep episodes. For distances longer than 322km, it may be essential that runners would need periods of sleep for them to successfully move forward in the race. As the race duration increases, the sleep requirement is seen to be higher.

Optimal Conditions

Infections can be reduced if marathoners receive sufficient sleep, good nutrition, rest between vigorous training sessions, and preventing contact with ill individuals. Getting sufficient sleep also has an impact with the prevention of musculoskeletal injuries.

Here is a video which indicates the normal sleeping duration, and ways to increase your sleep time:

Effects of Sleep Loss

Sleep loss can have a negative effect on athletes' physical performance. It has been noted that total sleep deprivation has lead to a decrease in endurance performance. Partial Sleep Deprivation (PSD) has shown a reduced time to exhaustion. There are differing views and results obtained from studies regarding the effect of PSD. Some studies have shown there running to exhaustion was not affected by PSD.

The loss of sleep has negative effects such as a heightened perceptual effort, and decreased emotional and cognitive function. The reduced cognitive function can be accompanied with a reduced psychomotor performance, via decreased vigilance, accuracy, and alertness. There can be a changed state of mood, which can be involved in a reduced endurance performance. Rating of perceived exertion can also be heightened in the presence of PSD or TSD.

The study comparing runners with PSD and a control condition of runners getting 8 hours of sleep found that the controls were able to run a further distance, and at a greater speed compared to the PSD condition. There was a significant effect for the control condition when considering parameters such as HR, VE, and VO2. There was no significant effect of sleep on the lactate produced during the runs between the control and PSD conditions. The PSD condition had an overall lower oral temperature at rest, compared to the control condition. Sleepiness, stress, and fatigue were higher in the PSD condition. There were no significant effects of either sleep condition on muscle soreness. The RPE scores were significantly higher in the PSD condition than the control condition. Motivation had no significant difference between the two groups. When considering mood, it was shown that depression, confusion, fatigue, and anxiety were increased, with a decrease in vigor after the PSD condition, at rest and after exercise. Reaction time is seen to be lower in the control group after exercise compared to the PSD condition.

The study indicated that pacing and endurance performance was greatly affected after the PSD condition. It was observed that mentally fatiguing conditions and an increased perceived exertion negatively impacted physical performance. This was seen in the PSD condition, with a decrease in the distance run, and the pacing characteristic of the runner. Cognitive processes were also affected with PSD. There was a deficit in attentional abilities with the PSD condition receiving only 4 hours of sleep. Decision making during rest and after self-paced exercise was also affected in the PSD condition.

A study by Montgomery et al (1985), where the conditions of no exercise, a 90 minute run, and a marathon were compared in non-elite marathon runners, showed that there was a sleep disorder which consisted of a decrease in REM sleep with a reduced sleep duration after a marathon race, which could have been caused by stress from increased cortisol levels. Sleep quality was unaffected with the 90 minutes of running training.

In addition, when runners travel to different time zones for marathon races, depending on the distance, it is possible that they may suffer from sleep loss, due to fatigue from changes in their circadian rhythm.

Caffeine

An increased daily intake of caffeine was related to a lower total sleep duration. However, daily caffeine intake (and weekly alcohol intake) led to a faster marathon completion time.

Effects on Cardiorespiratory Health

Sleep deprivation, even for only one night, does have effects on cardiorespiratory health. Functions such as heart rate (HR), minute ventilation (VE), oxygen consumption (VO2), decreased within the duration of exercise to exhaustion. However, measurements remained unchanged with submaximal exercise to exhaustion.

Blue-light and the effect on sleep

To read about the overall effects of blue-light on sleep, see the page Blue Light and the Effect on Sleep.

As mentioned on this page, blue light may have a positive effect on performance, such as cognitive performance, alertness, reaction times, accuracy, daytime dysfunction, heart rate response, and handgrip strength. In general, this would be beneficial for athletes.

However, with the increased use of electronic devices and the poor effect of blue light on sleep, athletes would need to be more cautious and cognisant of the amount and duration of exposure to blue light, especially before sleeping. The exposure to blue-light and poor sleep can lead to increased fatigue, therefore poor performance. This should ideally be minimised in the athletic training or competing populations.

In marathon runners, the use of electronic devices before bedtime led to a longer time to fall asleep, and a longer marathon completion time. A longer time to fall asleep in turn led to a longer marathon completion time.

More frequent use of electronic devices in the hour before sleeping led to a longer time to fall asleep. Those marathoners who used electronic devices within an hour before falling asleep also had a longer marathon finish time. These factors were significantly associated with a poorer marathon completion time. However, it is noted that differing types of electronic devices may have varying effects on time to fall asleep.

Sleep Trackers

In addition to blue-light from electronic devices being used before bed-time, the use of sleep trackers can have a significant negative effect on sleep health in marathon runners. Runners who used a sleep tracker had a lower sleep satisfaction rating.

Orthosomnia can be quite prevalent in the sleep health of those marathoners using sleep trackers. This may be displayed as individuals focusing more on their sleep quality, and therefore resulting in a disturbed sleep. Marathon runners, or even endurance athletes, may be leaning towards orthosomnia, due to the likelihood of them paying more attention to the details of training, sleep, and lifestyle factors. The sleep trackers could also be providing inaccurate data to the users, giving them the perception of worse sleep quality.