Sleep Extension and Recovery in Rugby Union Players
Sleep is an important factor that has recently become of interest in the sporting arena. The benefits of sleep include memory consolidation and metabolism regulation, as well as aiding immune function, mood and recovery. Rugby Union has been “professional” since 1996 and, with the increased focus on success throughout the world, coaches, athletes and practitioners are investing time and resource into “small gains” in preparation, recovery and performance. Therefore, the purpose of this thesis was to quantify the quality and quantity of sleep in rugby union players and examine the effect of sleep extension on players’ perceptions of recovery, physical performance and skill acquisition.
In part one, sixty-one professional and semi-professional rugby union players (mean age ± SD; 23.2 ± 3.9 years) completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire, which assesses sleep quality over a one month period. Twenty (33%) scored greater than five indicating poor sleep, while 41 (67%) scored less than five indicating good sleep. The ethnic group with the highest mean PSQI score (5.64 1.96) and therefore the poorest sleep was Maori (n=11). When related to training phase, those in the off-season reported the highest score (5.45 ± 1.82) indicating poor sleep. Further investigation is needed to understand the contributing factors to sleep quality in rugby union players.
Part two was a repeated measures design with participants undertaking a three-week habitual sleeping period to establish a baseline for normal sleeping behaviour and then a five-week period of extended sleep. Fifteen rugby players at a professional and semi-professional provincial level with no previous sleep issues participated in the study. Peak velocity (m/s), mean power (W) for squat jump, body weight (kg), sum of 8 skin folds (mm) and time in bed (mins), self-reported sleep quality, fatigue, muscle soreness and passing accuracy were measured before and after the three week sleep extension phase. After sleep extension, the players had a small increase (ES = 0.46 ± 0.47) in time in bed from post-baseline. Sleep was only extended by an average of 22 minutes per night. There were no significant or meaningful changes in any performance related variables following the sleep extension. Sleep extension was only partially achieved during the season with these players and may explain minimal changes in variables measured, therefore promoting sleep extension to a meaningful level in-season was not achieved.
In conclusion, 33% of players were found to not sleep well (part 1). However, an intervention to try to extend sleep through basic education and monitoring did not appear to extend sleep sufficiently. Therefore, methods to help rugby players extend, as well as improve the quality of their sleep, in-season and therefore realise ‘potential’ benefits requires more careful consideration and research.