Saturday 23 July 2016

Sleep and Performance

 In any sport, successful performance requires a planned approach to training and recovery. Whereas healthy adults are recommended 7-9 hours of sleep each night, some athletes, under circumstances of need, are taught to aim for 9-10 hours of sleep. Coaches and athletes rate sleep as critical to optimal performance, but the reality is that athletes are not getting it. Poor or inadequate sleep affects athletic performance, recovery, and may have systemic effects. The effects of sleep on athletes are complex due to multiple mechanisms of action, as well as individual variations to required or perceived need of sleep and resilience to sleep restriction. Many studies have evaluated sleep deprivation, a prolonged period of sleep loss such as a whole night or longer; however, sleep restriction, the partial disturbance of the sleep-wake cycle, is more akin to real world experiences of athletes. The following is a sample of the evidence of sleep restriction in athletes that can help decision-making regarding the use of sleep support habits and/ or agents.
The amount of sleep an elite athlete obtains is influenced by their training schedule. Seventy nationally ranked athletes from seven different sports were monitored using wrist activity monitors and asked to complete sleep/training diaries for 2 weeks during normal training. Fatigue levels were recorded prior to each training session using a 7-point scale. Athletes, on average, awoke at 6:48 am, fell asleep at 11:06 pm, spent 8 hours and 18 minutes in bed, and obtained 6 hours and 30 minutes of sleep per night. Of particular interest is that on nights prior to training days, time spent in bed was significantly shorter, sleep onset, as well as awakening times were significantly earlier, and the amount of sleep obtained was significantly less. It is not surprising that shorter sleep durations were associated with higher levels of pre-training fatigue. Timing of training also plays a role, in that, early morning training start times reduce sleep duration and increase pre-training fatigue levels. 
Athletes from individual sports went to bed earlier, woke up earlier, and obtained, on average, 30 minutes less sleep than athletes from team sports.The same research group followed 124 elite athletes from five individual sports and four team sports for 7-28 nights. Wrist activity monitor data and sleep diaries were assessed. Averages of sleep markers were similar to the previous study, but significant variances were seen in the individual sport athletes.Increasing intensity of training in elite athletes negatively affects sleep quality, mood, and performance. 
In one study 13 highly-trained male cyclists participated in two 9-day periods of intensified training. Sleep was measured each night via wristwatch actigraphy. Mood state questionnaires were completed daily. Performance was assessed with maximal oxygen uptake. Percentage sleep time fell during intensified training despite an increase in time in bed. Sleep efficiency decreased during intensified training. Mood disturbance increased during intensified training. Performance in the exercise protocol fell significantly with intensified training. 
Overtraining of trained endurance athletes leads to poor sleep and illness.  In one study, 27 trained male triathletes were either randomized into a 3 weeks period of “overload” training or normal training, both with a week of moderate training preceding the variable training and a two-week taper following the variable training. Researchers measured maximal aerobic power and oxygen uptake (VO2max) from incremental cycle ergometry. After each phase questionnaires measured mood states, and incidences of illness and sleep were monitored using wristwatch actigraphy. Half of the individuals in the overload group were categorized as functionally overreached. This group demonstrated decreases in sleep duration, sleep efficiency, immobile time, and a higher prevalence of upper respiratory tract incidences. 
Some athletes report trouble sleeping the night prior to a competition. 
 Competitive Sport and Sleep questionnaire and the Pittsburgh Sleep Quality Index were given to 283 elite Australian athletes. 64.0% of athletes indicated worse sleep on at least one occasion in the nights prior to an important competition over the past 12 months. 82.1% reported the main sleep problem was falling asleep. 83.5% attributed this problem to thoughts about the competition and 43.8% reported nervousness. 59.1% of team sport athletes reported having no strategy to overcome poor sleep. 32.7% of individual athletes reported the same. 
Elite athletes sleep less after a game. 
 Ten elite male rugby players were monitored over a twelve night period for sleep quantity and efficiency. There was a statistically significant difference in sleep quantity on game nights compared to non-game nights, with players sleeping less on game nights. Athletes went to sleep later on game nights.
Night games, in elite athletes, results in reduced sleep duration and perceived recovery. 
 Sixteen elite soccer players completed a subjective online questionnaire twice a day for 21 days during the season. Players were asked about sleep duration, how long it took to fall asleep, time that they fell asleep and awoke, and how long it took to fully wake up. Players were also asked about how they felt they were recovering, mood, and performance. Subjects reported, on average, 24 minutes less sleep per night after night games. Perceived recovery on a 7-point scale dropped by -2.6 points which were not seen in training days or in day matches. 
 Individual needs of athletes should be considered which makes guidelines and even team schedules difficult. While researchers seek to elucidate exact mechanisms of sleep and effects of sleep restriction in athletes, and are hesitant to provide practical recommendations, current athletes may benefit from the knowledge and web of evidence that has thus far been accumulated.
Bottom line: Lack of sleep affects everything. From your performance in the office to the field. In today’s crazy hectic world it is hard to get enough sleep . Make monitoring your sleep one of your priorities.  Sweet Dreams !  

No comments:

Post a Comment


Success Fitness Training

Professional Personal Fitness Trainer