No time to snooze: the athlete’s sleep paradox

The Athlete’s Sleep Paradox

Researchers at the University of British Columbia propose that the relationship between sleep quality and physical activity is an inverted U-shape based on the level of physical fitness (see figure 2)⁽¹³⁾. Researchers at the Boston University in the USA show that increasing physical activity can improve sleep⁽¹⁴⁾. However, as discussed above, too much physical activity can lead to overtraining. Thus, the complex balancing act provides athletes and clinicians with a conundrum. 

The inverted U-shape demonstrates that sleep quality suffers at the extremes of physical activity. However, an athlete’s physical fitness modulates the optimal midpoint. Therefore, as physical fitness increases, the optimal sleep quality midpoint also increases. Low physical activity is associated with poor sleep quality regardless of fitness level. However, the benefits of physical activity on sleep quality are positive until acute fatigue or overtraining occurs from too much physical activity. The ‘tipping point’ for acute fatigue and overtraining depends on an adult’s physical fitness level.

Assessing Sleep Quality and Quantity

The first step in understanding sleep disturbance is to measure the athlete’s sleep quality and quantity. Polysomnography, which records brain activity and oxygen levels, is the gold standard but is intrusive and difficult to use outside of a lab setting⁽¹⁾. Wearable activity monitors are more commonly used to track sleep; however, many are unreliable, with only 1 of 80 apps and devices validated in clinical trials⁽¹⁵⁾. In addition, when using wearables, it is important to remember that these devices often overestimate sleep duration and underestimate the number of awakenings⁽¹⁶⁾.

Subjective questionnaires, such as the Athlete Sleep Screening Questionnaire, are tools to identify sleep issues and develop solutions. These questionnaires are easy to complete and allow clinicians to address mild sleep problems by identifying areas of improvement for sleep. However, moderate to severe sleep problems may warrant a referral to a sleep specialist⁽¹⁾. 

Interventions

Sleep guidelines recommend seven to nine hours per night for adults and eight to ten hours for adolescents. However, athletes may need more than this to fully recover, especially during periods with high training loads^(17,18). Therefore, an individualized approach to address sleep issues is best for health and performance. Using sleep monitors or questionnaires, clinicians should strive to understand the specific needs of their athletes and provide education accordingly.

Coaches and clinicians can also mitigate sleep issues by tailoring training schedules. Avoiding early morning or late evening training times can help athletes get the necessary amount of continuous sleep. If training schedules do not allow for this, then daytime naps can supplement total sleep quantity. Sleep banking for at least one week before competition is another strategy to help when schedules impact sleep routines⁽¹⁾. Clinicians and athletes should use caution when using sleep monitors. Some athletes may become hyper-focused on the data, increasing cognitive arousal and resulting in worse sleep.

Tips for improving sleep hygiene⁽¹⁹⁾.

1. Go to sleep and wake up at a similar time each day to help set the natural biological clock.
2. Avoid eating, working, or watching TV in bed.
3. If you are unable to fall asleep within 20 minutes, leave your bed and return when sleepy.
4. Develop a bedtime routine which may include reading or meditating.
5. Avoid stimulating or stressful activities before bedtime.
6. Avoid moderate to vigorous exercise before bedtime when possible.
7. Avoid caffeine and alcohol for at least four hours before bedtime.
8. Avoid unprescribed and over-the-counter sleeping pills.
9. Make your sleeping environment comfortable and relaxing.
10. Remove excess light and noise. Consider using earplugs, light-blocking curtains, or an eye mask. 
11. Keep the temperature at a cool, comfortable level.
12. Stop using light-emitting electronics at least 30 minutes before bedtime, as blue light can disrupt melatonin production.

Conclusion

Inadequate sleep impairs sports performance and recovery. The physical activity-sleep relationship requires further investigation. Future research will need to reveal if and when a ‘tipping point’ exists and the amount of physical activity that negatively affects sleep. This is critical to understand the sleep recommendations for athletic success. Sleep disturbance is highly prevalent among athletes, and improvements in sleep quality and quantity will enhance performance. Clinicians should consider all factors when managing sleep behavior in athletes. 

References

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