The relationship between objective measures of sleep and training load across different phases of the season in American collegiate football players

ABSTRACT Purpose: Despite the perceived importance of sleep for American collegiate football (ACF) players, particularly given the schooling and athletic expectations for these players, descriptions of the duration and quality of sleep are limited. Thus, this study investigated the relationship between objective measures of sleep and training load across different phases of the ACF season. Methods: 23 ACF players’ (21.1 ± 1.2 years; 108.0 ± 20.0 kg). sleep/wake behaviour and daily external training load were assessed using wristwatch actigraphy and accelerometry (PlayerLoadTM [PL]), respectively, for a minimum of 3 nights/days in each phase (Off-season, Camp [Pre-season], In-Season and School). The relationships between each sleep metric and both season phase and external training load were assessed using linear mixed models. Results: Overall, total sleep time was very likely shorter in Camp (−41 ± 13 min, effect size [ES 0.68 ± 0.36[), almost certainly shorter In-Season (−56 ± 14 min, ES 0.93 ± 0.39) and likely shorter in School (−28 ± 15 min, ES 0.46 ± 0.42) compared to the Off-season phase. There was almost certainly a difference in sleep latency during the school phase (ES = 4.67 ± 2.03). Conclusion: These data suggest sleep time is reduced during periods of intensified training in ACF players. Of further concern are the demands placed upon student-athletes during the School phase, where aspects of sleep can be compromised.