Effect Of Sleep Efficiency On Relative External Workload In Collegiate Division 1 Soccer Players

PURPOSE: Increased sleep quality has been associated with increased performance, increased competitive success and reduced risk of injury in athletes. However, it is unclear how sleep quality from the previous night affects the execution of the allocated workload of the session, be it training or competition. Thus, the purpose of this study was to explore the association between sleep efficiency and external workload metrics in NCAA Division 1 soccer players. METHODS: Twenty NCAA Division I male soccer players (mean ± SD; age, 21 ± 2y; mass, 75.1 ± 6.0 kg; height, 178.0 ± 6.9 cm; body fat, 7.1 ± 3.7%; VO2max, 50.9 ± 1.6 ml·kg-1·min-1) competing in the 2018 season participated in this study. Participants wore a GPS and heart rate monitor for all training and competitions (Total observations: n = 502, Competition: n = 187, and Training: n = 315) to collect workload metrics and completed a daily sleep diary to assess sleep efficiency. Pearson correlation was used to explore any associations that may exist between sleep efficiency and workload metrics. RESULTS: As sleep efficiency increased there was a significant decline (r(500) = -0.106, p = 0.017) in the number of decelerations occurring in zone 4 (<-3.00 ms-2 ). However there were no significant associations when comparing sleep efficiency to average heart rate during a session (r(500) = -0.049, p = 0.271), total distance covered during a session (r(500) = -0.017, p = 0.698), number of accelerations in acceleration zones 1-4 (p = 0.057 - 0.826), number of decelerations in deceleration zone 1-3 (p = 0.500 - 0.977). CONCLUSION: While sleep efficiency the night before a training session/competition was associated with the number of decelerations occurring in zone 4, the highest rate of deceleration, there was no influence of sleep efficiency on other external workload measures during a Division I collegiate soccer season. Exploring the bidirectional relation between sleep and workload in collegiate athletes may yield additional insights into the impact of sleep on performance.