Although not yet fully understood, the role of sleep is essential to our proper functioning, both physiologically and psychologically. Sleep is important for energy conservation, nervous system recovery, host-defense mechanisms and maintaining optimal sports performance. The minimum amount of sleep required to maintain these functions is therefore a central issue for high performance sport.
The US National Sleep Foundation recommends 8-10 hours of sleep per night for adolescents (14-17 years), 7-9 hours of sleep per night for young adults (18-25 years) and 7-8 hours of sleep for other adults (26-64 years). Various studies have already observed that the amount of sleep in elite athletes is often insufficient in relation to these recommendations. However, these guidelines are very broad and do not take into account the inter-individual differences in sleep requirements of each athlete and the impact that sleep deprivation can have on performance, with some athletes coping better than others. What is the reality?
To find out more, Australian researchers studied the sleep patterns of 175 elite athletes (30 women and 145 men) from 12 sports (Australian football, basketball, cricket, kayaking, race walking, mountain biking, road cycling, rugby union, football, swimming, track cycling and triathlon). All athletes were members of their respective national teams. The athletes who participated in this study were volunteers, as the request often came from the technical staff wanting to know more about sleep optimisation for their athletes. Of these athletes, 11 were considered adolescents, 128 were young adults and 26 were adults.
The researchers studied the athletes' sleep over a minimum of 4 consecutive nights using a combination of 2 methods: 1) a simple paper and pencil method to record each night the time the athlete lies down to sleep and the time the athlete gets up from bed. And 2) with an activity monitor (Actiwatch-64 and Actical Z-series, Philips) worn on the wrist, the start of sleep, the end of sleep and the number of hours of sleep were recorded. These bracelets have been scientifically validated in comparison with polysomnography (laboratory sleep study).
In addition to these recordings, the scientists asked each athlete to answer a few questions:
Finally, the athletes were followed for an average of 12 ± 4 nights and the main results show that on average, the duration of sleep per night was 6.7 ± 0.8 hours, and that it was significantly lower than the duration that the athletes themselves considered necessary (8.3 ± 0.9 hours). The general recommendations of 7 to 9 hours of sleep per night are not met here, with individual needs to be assessed. In terms of maximum values, one athlete stated that he needed only 5.5 hours of sleep, while two others needed 11 hours.
Figure 1. Relative frequency of athletes habitual sleep duration.
On average, the athletes fell asleep around 23:24 ± 0:42 and woke up around 7:18 ± 0:48. Regarding their satisfaction with the amount of sleep obtained, the athletes rated 6.8 ± 1.6 / 10. Regarding the quality of their sleep, they gave a score of 3.9 ± 0.9 /6. Only 3% of the athletes got the amount of sleep they wanted, and 71% of the athletes slept at least 1 hour less than they would have liked. The average sleep debt (i.e. the difference between the amount of sleep desired and the amount actually slept) was 96 ± 60.6 minutes.
Individual athletes fell asleep earlier and woke up earlier than team athletes. Nevertheless, individual athletes slept for less time. Triathletes slept the least and rugby players the most. But there were no differences in ideal sleep requirement, sleep quality or satisfaction with the amount of sleep obtained. Finally, no difference was observed between women and men.
These results are interesting because they show the discrepancy between the amount of sleep athletes would like to get and the hours they actually sleep during a normal period of their sporting career. Of course, even though the bracelets have been validated against polysomnography, there is still a difference in the measurements observed. The authors of the study indicate that these bracelets may overestimate sleep by 18 ± 52 minutes and underestimate it by 54 ± 36 minutes. It is therefore important to take these levels of accuracy into account when interpreting the results and especially to couple these measurements with sleep quality questionnaires. Another point to note is that this study did not take into account whether athletes took naps during the day (which is generally a good way to increase sleep capital), and therefore potentially underestimated sleep duration. However, other studies have shown that the frequency of napping is low in elite athletes and does not sufficiently increase total sleeping time.
Studies have shown that one to two nights with 3-5 hours of sleep negatively impacts sports performance. But what is the impact of a light sleep deficit in long term? Studies in sedentary people have shown that 7 nights of 5 and 7 hours of sleep decreased response time by 23% and 12%, respectively, compared to nights of 9 hours of sleep. And 14 nights of 6 hours of sleep increased the rate of errors in a response time task by 177% compared to nights of 8 hours of sleep. In this study, 71% of the athletes did not get the amount of sleep they desired and 38% of the athletes slept less than 6.5 hours during 12 ± 4 nights. This could have an impact on cognitive and physical performance, but unfortunately this is only a guess as we will have to wait for randomised controlled studies over longer periods of time to see the impact of sleep optimisation on sports performance.
Several strategies are then possible to increase sleep time: 1) delay morning training sessions if possible, 2) define with the athlete a time window to fall asleep between 10pm and 10.30pm, for example. And in this case, if possible, a reorganisation of training sessions at the end of the day can be envisaged. All of this is of course theoretical and should be adapted according to the athlete's personal needs, the sport discipline, the availability of training facilities, etc.
We remind you that you can quote articles by limiting your quotation to 200 words maximum and you must include a nominative link to this one. Any other use, especially copying in full on forum, website or any other content, is strictly prohibited. In doubt, contact us.
Copyright © 2011-2024 - www.sci-sport.com - All rights reserved