Sleep deprivation athletic performance

Unfortunately, at least three research protocol features are needed to define the effects of sleep deprivation on athletic performance with any accuracy, (a) The research protocol should isolate the homeostatic from the circadian components as the two so frequently confound each other (3,4). (b) The protocol should include a meaningful competitive event to decrease the chance of motivational confounds and reduce the distortion inherent in extrapolating pieces to a whole (i.e., anaerobic capacity of the quadriceps muscle does not necessarily predict World Cup victory), (c) Finally, the protocol should effectively reduce the myr-... 

Athletic performance includes not only the competitive event itself, but also optimal training and avoidance of injuries prior to and during the event. Therefore, in addition to reviewing the effects of sleep deprivation on athletic performance measures, this chapter will also examine similar observations on athletic training and injuries. 

Relatively few studies have examined the effects of sleep deprivation on athletic performance in the field and even fewer are associated with a meaningful competitive event. Therefore, indirect evidence from military research and subjective reports from elite athletes participating in ultraendurance races will also be reviewed. 

The Race Across America (RAAM) is an all-out 2900-mile solo bicycle race across the United States. Unlike the Tour de France, there are no programmed stops or rest periods. The winner typically rides across the entire country in 8 days. Smith et al. (5) studied a total of seven athletes over 3 years and reported that the winners averaged approximately 2 hr of sleep per day. It was concluded that some athletes have the remarkable ability to perform and win ultraendurance races in the face of severe sleep deprivation. 

Ultraendurance races like RAAM and the Eco-Challenge exemplify the classic question in sleep deprivation research on athletes, At what point does sleep deprivation become detrimental to athletic performance It is a question of probability rather than possibility. For the moment, the answer appears to vary greatly. 

In conclusion, field studies are limited in number and precision. High variance in study design no doubt contributes to inconsistencies in findings. Perhaps the best evidence for athletic performance decrement secondary to significant sleep deprivation is the complete absence of any study that has deliberately deprived elite athletes of sleep prior to a meaningful competitive event. There have been ample opportunities, but apparently no volunteers. 

Endurance and time to exhaustion are also important components of athletic performance. Decreases in either measure were observed in several studies (19,21,38 12). Holland (38) noted a 10% reduction in work performed during all-out cycle ergometer exercise after 24 hr of sleep deprivation. Brodan and Kuhn (39) evaluated subjects (n = 7, sleep debt = 120 hr) with the Harvard step test (reflects cardiorespiratory endurance and recovery) and revealed adaptation during the test but impaired recovery. Martin (41) utilized treadmill testing at 80% V02 max and found decreased time to exhaustion, increased perceived exertion, and increased minute ventilation (n = 8, sleep debt = 36 hr). Martin and Chen (42) revealed a 20% reduction in time to exhaustion after 50 hr of sleep deprivation. Decreased time to exhaustion after 30 hr of sleep deprivation has been demonstrated even when subjects were allowed caffeine intake (21). 

Athletic injuries impair performance, prolong training and, at worst, end careers or even lives. Avoiding injury is critical to athletic performance, except in those extremely rare examples where the adversity of injury propels an athlete beyond even his/her own personal best. Sleep deprivation is commonly cited as a precipitating or causal factor in accidents and injuries (see Chaps. 10, 12, 14, and 15). It is therefore curious to discover that there is essentially no scientific research on sleep deprivation and athletic injury. Lund (75) followed 12 volleyball players over 61 hr of sleep deprivation. There were 29 minor injuries, which seemed elevated, but there was no control group for comparison. 

Illness is not considered injury, but it shares similar adverse effects on athletic training and performance. It is doubtful any athlete would choose to have the flu during competition. Sleep deprivation and human immune function has been extensively researched and reviewed (79). Significant detrimental effects on immune function have been demonstrated after both complete and partial sleep deprivation (56,79). The interactions are complex. Some sleep deprivation and strenuous exercise may even enhance certain aspects of immune function (80). This represents yet another area of much-anticipated research and potential impairment to athletic performance. 

In other studies of sleep deprivation the adverse effects on general human performance were dependent upon time-on-task. Duration of testing was often only a few minutes in the athletic performance tests reviewed. Cognitive performance is particularly sensitive to time-on-task testing after sleep deprivation. No study has directly examined cognitive athletic performance, let alone across various time frames. Results of Reilly and Piercy (37) suggest time-on-task is an important differentiator both physically and cognitively. 

Notwithstanding, sleep deprivation tends to have greater adverse effects on the older adult. With the exception of one protocol (40), all of these studies were limited to young adults, which creates potential inaccuracies when extrapolating to the youth soccer league or the aging baby boomer who runs marathons. Optimal performance is important to athletes of all ages and abilities. 

Both partial and complete sleep deprivation have plausible adverse effects on athletic performance, training, and injuries. Research conclusions range widely from no effects to very significant effects, with the absence of any study describing beneficial effects after sleep deprivation. Therefore, an optimal sleep strategy clearly represents a potential performance advantage for athletes. 

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