Beaven, Christopher MartynDriller, Matthew W.Argus, Christos K.Gill, Nicholas D.Teece, Angus R.2026-05-252026-05-252026-05-21https://hdl.handle.net/10289/18296Sleep plays a vital role in daily functioning of biological, cognitive, and physical performance for humans. Additionally, sleep has been widely regarded by athletes to play an important role in recovery from training and competition. Despite the increasing amount of sleep research in athlete populations, elite team sport athletes are still underrepresented in the literature, specifically in collision-based sports, despite the unique challenges facing this population. Therefore, this PhD thesis aims to enhance the understanding of sleep habits of professional, male Rugby Union athletes in both training and competition environments. Finally, the thesis evaluates interventions that could improve sleep in the same population. Study One subjectively assessed the sleep habits of 224 Rugby Union athletes across multiple levels of competition in Rugby Union athletes (academy, semi-professional, and professional) who completed the Athlete Sleep Behaviour Questionnaire and the Pittsburgh Sleep Quality Index. The results highlighted that differences exist between different levels of competition for specific sleep behaviours; however, sleep behaviours could be improved for all levels of competition in Rugby Union athletes. Study Two assessed the differences in sleep quality, quantity, and behaviours between 38 elite male and 27 elite female Rugby Union athletes via the Athlete Sleep Behaviour Questionnaire and the Pittsburgh Sleep Quality Index. Male athletes reported significantly longer sleep duration and higher sleep efficiency. The study highlighted that differences existed between elite male and female Rugby Union athletes and that elite male and female athletes face specific sleep challenges. Study Three investigated nightly sleep duration during a three-week preseason training period in 29 professional Rugby Union athletes using wrist actigraphy. Aerobic capacity and body composition were assessed at Baseline, at Week 3, and at Week 5. Participants were split into two groups for analysis as less than 7 h 30 min per night or greater than 7 h 30 min per night. The results highlighted that longer sleep duration during a preseason phase may assist in enhancing physical qualities including aerobic capacity and body composition. Study Four assessed the sleep and wake variability of 23 professional Rugby Union athletes during a preseason period of training. Sleep was monitored via wrist actigraphy for three weeks and the athletes completed a daily wellness questionnaire. Athletes were split into two groups based on their calculated sleep regularity index (regular and irregular). The regular group displayed significantly longer sleep duration and greater sleep efficiency and less wake episodes. The results highlighted that minimising variability in sleep onset and offset is beneficial for increasing sleep duration. Study Five investigated the prevalence of naps on match day in 30 professional Rugby Union athletes and its subjective link to match performance across a 17-match season. Athletes were asked about their napping practices and their perceived performance during match play. Additionally, three team coaches evaluated match performance of each participant. The results highlighted that 86% of athletes used pre-match naps with a greater amount taken during away matches compared to home matches. Additionally, the odds of an athlete rating their performance as “good” was increased when they napped and won the match. Study Six investigated the effectiveness of daytime naps on afternoon physical performance in a randomized cross-over design with 15 professional Rugby Union athletes. Athletes performed a nap or no nap condition on two occasions, separated by one week. Baseline testing of reaction time, self-reported wellness, and a 6-second peak power test on a cycle ergometer was completed in the morning followed by 2 x 45-minute training sessions. Athletes completed nap or no nap condition at 1200 h. Baseline measures were retested in the afternoon in addition to a 30-mintue fixed intensity interval cycle and a 4-minute maximal effort cycling test. The study highlighted that utilising daytime naps between training sessions on the same day, improved afternoon peak power and lowered perception of fatigue, soreness and exertion during afternoon training. In summary the series of studies in this thesis provides a foundation for understanding sleep in elite Rugby Union athletes. Sleep challenges and disturbances are prevalent amongst Rugby Union athletes in both training and competition environments. Results show that methods such as consistency in sleep onset and offset, daytime naps, and extending sleep duration can have benefits for Rugby Union athletes. These studies provide valuable information on sleep habits of not only professional Rugby Union athletes but rugby athletes of all levels and codes, which can be used to inform sleep hygiene protocols to target aspects that are most relevant within a given population. Moreover, aspects such as allowance of daytime naps and consistency in schedule to allow for consistent sleep and wake times should be considered when designing recovery within training programs.enAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.sleeprecoveryperformancerugby unionsleep hygieneThesis