Prevalence of sleep disorders and sleep problems in an elite super rugby union team

Sleep Behaviors and Nutritional Knowledge in Amateur and Professional Combat Sport Athletes

ABSTRACT

Dunican, IC, Galpin, A, Turner, M, and Reale, R. Sleep behaviors and nutritional knowledge in amateur and professional combat sport athletes. J Strength Cond Res 38(9): 1627-1634, 2024-Combat sports is a term applied to various competitive contact sports involving 2 competitors engaging in a bout or contest under a specific ruleset. Little is known about combat sports athletes' sleep and nutritional knowledge. This study aimed to assess (a) sleep behaviors, (b) alcohol and shiftwork disorders, and (c) the nutritional knowledge of combat sports athletes. Subjects completed various demographic questions and estimations of their weight management practices and validated surveys, including the Athlete Sleep Behavior Questionnaire, Shiftwork Disorder (SWD) Screening Questionnaire, Alcohol Use Disorders Identification Test, and the Abridged Nutrition for Sports Knowledge Questionnaire. A total of 844 combat sports athletes completed the survey, 79% male, height of 177 ± 10 (cm), and body mass of 79 ± 15 (kg). Subjects were categorized into their specific combat sport type (e.g., boxing or Brazilian jiu-jitsu [BJJ]) and by their level (professional or amateur). Sleep quality was average for all combat sport types and risk prevalence of shiftwork disorder at 11%. Mann-Whitney U tests revealed that amateurs, compared with professional strikers ( p = 0.046, CLES = 0.80), boxers ( p = 0.01, CLES = 0.78), and BJJ ( p = 0.046, CLES = 0.61) athletes, consumed significantly more alcohol. A Friedman test showed significant ( p < 0.001, W = 0.51) differences in weight between time points, with most combat sports athletes reducing weight for competition. An overall nutritional knowledge average of 55% was reported. This study highlights a critical gap in the knowledge and practices of combat sports athletes in relation to sleep behaviors and disorders, alcohol consumption, and nutritional knowledge, emphasizing the need for targeted educational interventions.

Sleep and cardiovascular disease

This review centres around the recent evidence in examining the intersection of sleep and cardiovascular disease (CVD). Sleep in this review will be further subdivided to consider both sleep quantity and quality along and will also consider some of the more common sleep disorders, such as insomnia and obstructive sleep apnoea, in the context of CVD. Sleep disorders have been further explored in several specific populations which are both at risk of sleep disorders and CVD. Secondly, the review will present some of the risk factors for CVD that are affected by sleep and sleep disorders which include hypertension, diabetes, and obesity. It will also examine the potential underlying mechanisms including inflammation, appetite control, endocrine, and genetic processes that are affected by sleep and sleep disorders leading to increased risk of CVD development. In addition, we will consider the observed bi-directional relationships between sleep and cardiovascular risk factors. For example, obesity, a risk factor for CVD can be affected by sleep, but in turn can increase the risk of certain sleep disorder development which disrupts sleep, leading to further risk of obesity development and increased CVD risk. Finally, the review will explore emerging evidence around lifestyle interventions that have included a sleep component and how it impacts the management of CVD risk factor. The need for increased awareness of the health effects of poor sleep and sleep disorders will be discussed alongside the need for policy intervention to improve sleep to facilitate better health and well-being.

Daytime naps improve afternoon power and perceptual measures in elite rugby union athletes-a randomized cross-over trial

Daytime naps are used by elite athletes in both training and match-day settings. Currently, there are limited interventional studies on the efficacy of napping on physical performance in elite team-sport athletes. Therefore, the objective was to investigate the effect of a daytime nap (<1 hour) on afternoon performance of peak power, reaction time, self-reported wellness, and aerobic performance in professional rugby union athletes. A randomized cross-over design was carried out among 15 professional rugby union athletes. Athletes performed nap (NAP) and no nap (CON) conditions on two occasions, separated by 1 week. Baseline testing of reaction time, self-reported wellness, and a 6-second peak power test on a cycle ergometer were completed in the morning, followed by 2 × 45-minute training sessions, after which athletes completed the NAP or CON condition at 1200 hours. Following the nap period, baseline measures were retested in addition to a 30-minute fixed-intensity interval cycle and a 4-minute maximal effort cycling test. A significant group × time interaction was determined for 6-second peak power output (+157.6 W, p < 0.01, d = 1.53), perceived fatigue (-0.2 AU, p = 0.01, d = 0.37), and muscle soreness (-0.1 AU, p = 0.04, d = 0.75) in favor of the NAP condition. A significantly lower perceived exertion rating (-1.2 AU, p < 0.01, d = 1.72) was recorded for the fixed-intensity session in favor of NAP. This study highlights that utilizing daytime naps between training sessions on the same day improved afternoon peak power and lowered perceptions of fatigue, soreness, and exertion during afternoon training in professional rugby union athletes.

Effects of sociodemographic and player characteristics on baseline cognitive performance in 1000 rugby players: A retrospective 8-year follow-up study

OBJECTIVES

To analyze the effects of sociodemographic and player characteristics on the Sport Concussion Assessment Tool and neuropsychological scores over 8 years in a large sample of rugby players.

DESIGN

An 8-year retrospective study of preseason clinical assessments of professional rugby players and players enrolled in training academies at professional clubs.

METHODS

The Sport Concussion Assessment Tool-3 or -5, Trail Making Test and Digit Symbol Substitution Test were administered prior to the start of the competition season for each player. Statistical analyses included: (i) descriptive analyses of sociodemographic, player and neuropsychological characteristics; (ii) multivariate models to identify factors influencing cognitive scores at the first visit; and (iii) linear mixed models to assess the evolution of the scores over the years.

RESULTS

One thousand players were included (mean age: 22.8, males: 92 %). Twenty-two percent of the athletes reported baseline symptoms. A higher level of education was associated with better cognitive scores at the first visit and over the years. Forwards had poorer processing speed performances compared to backs at the first visit and over repeated assessments. Finally, the number of examinations was associated with improved cognitive scores showing a practice effect on all the neuropsychological tests, except for the Standardized Assessment of Concussion 5th edition.

CONCLUSIONS

Results from this retrospective study could help to improve the management of athletes and return-to-play decision-making in collision sports.

Athlete Sleep Behavior Questionnaire in Japanese (ASBQ-J): An Adaptation and Validation Study

Purpose

The Athlete Sleep Behavior Questionnaire (ASBQ) is an 18-item self-reported questionnaire that can be used to screen for sleep disorders in athletes and assess environmental, behavioral, and sports-related factors along with sleep disorders. This study aimed to analyze the reliability and validity of the ASBQ translated into Japanese (ASBQ-J).

Patients and Methods

111 female collegiate athletes completed both the initial test and retest. Independent variables were what kind of sports they perform, level as an athlete, grade (freshman, sophomore, junior, senior), and age. The reliability of the survey was assessed using Cronbach's alpha and intraclass correlation, and Pearson's correlation coefficient was calculated to determine the correlation between the total ASBQ scores and three components which were routine/environmental, behavioral, and sports factors.

Results

A total of 37.8% of athletes had ASBQ scores equal or less than 36 indicating good sleep. However, 19.8% of athletes scored more than 42, indicating poor sleep. Cronbach alpha was 0.62 and 0.65 for test and retest, respectively. Intraclass correlation was 0.78 (P < 0.01), indicating sufficient internal consistency and test-retest validity. Mean ASBQ scores were 38.5 ± 5.0 and 37.0 ± 6.5 for test and retest, respectively, and it was not significantly different between the two groups (P = 0.37). The correlation coefficients between the ASBQ-J and component scores were all statistically significant (all P < 0.01).

Conclusion

ASBQ-J is a reliable questionnaire for assessing sleep disorders in athletes whose primary language is Japanese.

Comparing Perceived Sleep Quality, Practices, and Behaviors of Male and Female Elite Rugby Union Athletes with the Use of Sleep Questionnaires

Objective  To evaluate the differences in subjective sleep quality, quantity, and behaviors among male and female elite rugby union athletes through two common sleep questionnaires. Materials and Methods  A sample of 38 male and 27 female elite rugby union athletes filled out the Athlete Sleep Behavior Questionnaire (ASBQ) and the Pittsburgh Sleep Quality Index (PSQI). Global scores and individual items for each questionnaire were compared to assess differences between sexes. Results  Male athletes reported significantly longer sleep duration (7 h 50 m ± 50 m versus 7h 12 m ± 58 m respectively; p ≤ 0.01; d  = 0.70) and higher habitual sleep efficiency (88% versus 83% respectively; p  < 0.05; d  = 0.54) when compared with female athletes. Individual items of the ASBQ revealed significant differences between male and female athletes for five questions. Male athletes displayed higher instances of taking stimulants before training or competition and consuming alcohol within 4 hours of going to bed. Conversely, female athletes expressed greater thought or worry while in bed and a higher instance of training late at night. Discussion  Male athletes displayed better self-reported sleep quality and quantity than female athletes; however, the present study highlighted that male and female elite rugby union athletes face specific challenges that differ. It appears that the differences observed between male and female elite rugby union athletes may be due to differing levels of professionalism or differences in training or competition schedules.

The Impact of Kiwifruit Consumption on the Sleep and Recovery of Elite Athletes

BACKGROUND

Poor sleep and resultant under-recovery can negatively impact training adaptations, increase the risk of injury and reduce subsequent performance. Due to the 'food first' approach adopted by many athletes, there is scope for investigation of 'functional food' based interventions (i.e., kiwifruit contains melatonin which plays a role in circadian rhythm regulation) designed to promote athlete recovery and/or enhance sleep quality and quantity.

METHODS

Following the baseline assessment (Week 1) all subjects began the intervention (Weeks 2-5). During the 4-week intervention, participants were asked to consume 2 medium-sized green kiwifruit (Actinidia Deliciosa) an hour before bed. Participants completed a questionnaire battery at baseline and post-intervention, and a daily sleep dairy for the duration of the study.

RESULTS

The results demonstrated a positive impact of kiwifruit consumption on key aspects of sleep and recovery in elite athletes. From baseline to post-intervention, there were clinically significant improvements in sleep quality (i.e., improved PSQI global scores and sleep quality component scores) and improvements in recovery stress balance (reduced general stress and sports stress scales). Moreover, the intervention improved sleep as evidenced by significant increases in total sleep time and sleep efficiency % and significant reductions in number of awakenings and wake after sleep onset.

CONCLUSION

The findings broadly suggested that kiwifruit does impact positively on sleep and recovery in elite athletes.

Pyjamas, Polysomnography and Professional Athletes: The Role of Sleep Tracking Technology in Sport

Technological advances in sleep monitoring have seen an explosion of devices used to gather important sleep metrics. These devices range from instrumented 'smart pyjamas' through to at-home polysomnography devices. Alongside these developments in sleep technologies, there have been concomitant increases in sleep monitoring in athletic populations, both in the research and in practical settings. The increase in sleep monitoring in sport is likely due to the increased knowledge of the importance of sleep in the recovery process and performance of an athlete, as well as the well-reported challenges that athletes can face with their sleep. This narrative review will discuss: (1) the importance of sleep to athletes; (2) the various wearable tools and technologies being used to monitor sleep in the sport setting; (3) the role that sleep tracking devices may play in gathering information about sleep; (4) the reliability and validity of sleep tracking devices; (5) the limitations and cautions associated with sleep trackers; and, (6) the use of sleep trackers to guide behaviour change in athletes. We also provide some practical recommendations for practitioners working with athletes to ensure that the selection of such devices and technology will meet the goals and requirements of the athlete.

Mandibular Advancement Device Therapy in Japanese Rugby Athletes with Poor Sleep Quality and Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) may contribute to poor sleep quality. This study assessed subjective sleep quality, the Respiratory Event Index (REI), reaction times, and the therapeutic effects of a custom-made mandibular advancement device (MAD) in male Japanese elite rugby athletes. The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and level III sleep test (REI and minimum oxygen saturation [SpO2 min]) were used to evaluate sleep quality. MAD therapy was used daily for 3 weeks. A telephone-based reaction time test of kinetic vision (the ability to identify moving objects) was recorded within 15 min of waking and over 5 days of pre- and post-MAD therapy. Differences in variables were evaluated using paired t-tests. Of the 42 players (mean age, 26.3 ± 3.7 years; mean body mass index, 28.7 ± 3.2 kg/m2) included in this study, 29 (69.0%) had poor sleep quality (PSQI > 5.5), and 27 were diagnosed with OSA (64.3%) (mild = 16/moderate = 9/severe = 2). Six were treated with MAD therapy, which significantly improved the REI (p < 0.01), SpO2 min (p < 0.001), ESS score (p < 0.001), reaction times (p < 0.01), and sleep quality. A significant reduction in reaction times suggests that OSA treatment can improve kinetic vision. Future studies should systematically evaluate the impact of sleep-disordered breathing on kinetic vision in athletes.

Sleep and Athletic Performance: Impacts on Physical Performance, Mental Performance, Injury Risk and Recovery, and Mental Health: An Update

Sleep health is an important consideration for athletic performance. Athletes are at high risk of insufficient sleep duration, poor sleep quality, daytime sleepiness and fatigue, suboptimal sleep schedules, irregular sleep schedules, and sleep and circadian disorders. These issues likely have an impact on athletic performance via several domains. Sleep loss and/or poor sleep quality can impair muscular strength, speed, and other aspects of physical performance. Sleep issues can also increase risk of concussions and other injuries and impair recovery after injury. Cognitive performance is also impacted in several domains, including vigilance, learning and memory, decision making, and creativity.

Cannabis and Athletic Performance

Cannabis is widely used for both recreational and medicinal purposes on a global scale. There is accumulating interest in the use of cannabis and its constituents for athletic recovery, and in some instances, performance. Amidst speculation of potential beneficial applications, the effects of cannabis and its two most abundant constituents, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), remain largely un-investigated. The purpose of this review is to critically evaluate the literature describing the effects of whole cannabis, THC, and CBD, on athletic performance and recovery. While investigations of whole cannabis and THC have generally shown either null or detrimental effects on exercise performance in strength and aerobic-type activities, studies of sufficient rigor and validity to conclusively declare ergogenic or ergolytic potential in athletes are lacking. The ability of cannabis and THC to perturb cardiovascular homeostasis warrants further investigation regarding mechanisms by which performance may be affected across different exercise modalities and energetic demands. In contrast to cannabis and THC, CBD has largely been scrutinized for its potential to aid in recovery. The beneficial effects of CBD on sleep quality, pain, and mild traumatic brain injury may be of particular interest to certain athletes. However, research in each of these respective areas has yet to be thoroughly investigated in athletic populations. Elucidating the effects of whole cannabis, THC, and CBD is pertinent for both researchers and practitioners given the widespread use of these products, and their potential to interact with athletes' performance and recovery.

Deconstructing athletes' sleep: A systematic review of the influence of age, sex, athletic expertise, sport type, and season on sleep characteristics

PURPOSE

This systematic review aimed to describe objective sleep parameters for athletes under different conditions and address potential sleep issues in this specific population.

METHODS

PubMed and Scopus were searched from inception to April 2019. Included studies measured sleep only via objective evaluation tools such as polysomnography or actigraphy. The modified version of the Newcastle-Ottawa Scale was used for the quality assessment of the studies.

RESULTS

Eighty-one studies were included, of which 56 were classified as medium quality, 5 studies as low quality, and 20 studies as high quality. A total of 1830 athletes were monitored over 18,958 nights. Average values for sleep-related parameters were calculated for all athletes according to sex, age, athletic expertise level, training season, and type of sport. Athletes slept on average 7.2 ± 1.1 h/night (mean ± SD), with 86.3% ± 6.8% sleep efficiency (SE). In all datasets, the athletes' mean total sleep time was <8 h. SE was low for young athletes (80.3% ± 8.8%). Reduced SE was attributed to high wake after sleep onset rather than sleep onset latency. During heavy training periods, sleep duration and SE were on average 36 min and 0.8% less compared to pre-season and 42 min and 3.0% less compared to in-season training periods, respectively.

CONCLUSION

Athletes' sleep duration was found to be short with low SE, in comparison to the general consensus for non-athlete healthy adults. Notable sleep issues were revealed in young athletes. Sleep quality and architecture tend to change across different training periods.

Around the world in 16 days: the effect of long-distance transmeridian travel on the sleep habits and behaviours of a professional Super Rugby team

There is a scarcity of research examining the effects of long-distance transmeridian travel (LDTT) on the sleep and match performance of team sport players. To address this, 37 elite male rugby union players from a Super Rugby team undertaking LDTT were recruited. The participants completed validated sleep questionnaires and wore a wrist-worn activity monitor (Readiband™) during a Super Rugby season (including during periods of LDTT crossing 5, 6, and 13 time-zones) to ascertain objective measures of sleep. Sleep measures were compared using mixed model analysis to ascertain the effects of competition and LDTT on sleep. Total sleep time (TST) increased in the days prior to matches, and decreased following matches (accompanied by a later time at sleep onset), particularly when next-day early-morning flights were required. TST was decreased when sleep was attempted during LDTT, except for in the last travel bout where players napped in addition to achieving night-time sleep. TST was also reduced for the night immediately following LDTT, except for in Condition 3 where players delayed wake time and also achieved naps. This study exemplifies the challenges that team-sport athletes face in obtaining regular sleep when LDTT is required.

Complete sleep evaluation of top professional cross-country mountain bikers athletes

BACKGROUND

Despite growing interest in athletes' sleep, few studies have focused on professional athletes, especially in individual sports. Moreover, limited investigations included female athletes. This study aims to evaluate sleep chronotype, as well as objective and subjective sleep characteristics in male and female professional cross-country mountain bikers.

METHODS

Thirteen athletes (7 males and 6 females) of the French national team took part in this study. The Chronotype was assessed by the Horne and Östberg Morningness-Eveningness Questionnaire and sleep by actigraphy for one month, by ambulatory polysomnography (PSG) for one night and by the Pittsburgh Sleep Quality Index.

RESULTS

Most athletes (77 %) are classified as moderately morning type and a minority of athletes (23 %) are intermediate type. Athletes sleep on average 8 hours per night and during the night recorded by PSG, N3 and REM sleep stages represented 21.2 ± 3.4 % and 20.9 ± 3.1 % of the total sleep time, respectively. These good sleep parameters were confirmed by subjective data with 77 % good sleepers. Except the poorer subjective sleep quality in female athletes (5.7 ± 1.6) compared to male athletes (2.6 ± 1.7, p < 0.05), no significant sex difference was found for all characteristics evaluated.

CONCLUSIONS

The professional status of these athletes and the organization of mountain bike calendar may explain their good sleep characteristics.

Comparison of sleep between youth elite amateur athletes and professional athletes

Recent studies suggest that professional athletes seem to experience significant sleeping problems. However, little is still known about the occurrence of sleeping challenges at different stages of an athletic career. This descriptive study aimed to compare the sleep of professional athletes with younger elite amateur athletes. A total of 401 sportsmen, 173 youth elite amateur athletes and 228 professional athletes fulfilled a validated questionnaire. The self-estimated quality of sleep (on a linear scale 0–10) was significantly better in youth, being 7.9 compared to 7.4 (p < 0.001). The professional athletes had a significantly higher risk for sleeping problems, especially during the competitive season (OR = 7.3, 95% confidence interval 4.1–12.9) and they also used significantly more sleep medications (OR = 8.3, 95% confidence interval 1.7–4.1). Interestingly, majority of youth athletes (85.4%) had received adequate sleep counselling compared with professional athletes (58.1%), (p < 0.001). Furthermore, 75.8% of professional athletes considered that additional sleep counselling would improve their performance compared with only 45.6% of youth athletes (p < 0.001). Our study demonstrates that compared with the younger counterparts, professional athletes experience impaired sleep quality and significantly more sleeping problems. There may be various underlying factors to induce the problems. The early intervention with sleep counselling may play an important role in preventing these problems and, therefore, it is recommended to be integrated in athletes’ overall training process.

Sleep and Performance during a Preseason in Elite Rugby Union Athletes

Background: Preseason training optimises adaptations in the physical qualities required in rugby union athletes. Sleep can be compromised during periods of intensified training. Therefore, we investigated the relationship between sleep quantity and changes in physical performance over a preseason phase in professional rugby union athletes. Methods: Twenty-nine professional rugby union athletes (Mean ± SD, age: 23 ± 3 years) had their sleep duration monitored for 3 weeks using wrist actigraphy. Strength and speed were assessed at baseline and at week 3. Aerobic capacity and body composition were assessed at baseline, at week 3 and at week 5. Participants were stratified into 2 groups for analysis: <7 h 30 min sleep per night (LOW, n = 15) and >7 h 30 min sleep per night (HIGH, n = 14). Results: A significant group x time interaction was determined for aerobic capacity (p = 0.02, d = 1.25) at week 3 and for skinfolds at week 3 (p < 0.01, d = 0.58) and at week 5 (p = 0.02, d = 0.92), in favour of the HIGH sleep group. No differences were evident between groups for strength or speed measures (p ≥ 0.05). Conclusion: This study highlights that longer sleep duration during the preseason may assist in enhancing physical qualities including aerobic capacity and body composition in elite rugby union athletes.

The Sleep and Recovery Practices of Athletes

BACKGROUND

Athletes maintain a balance between stress and recovery and adopt recovery modalities that manage fatigue and enhance recovery and performance. Optimal TST is subject to individual variance. However, 7-9 h sleep is recommended for adults, while elite athletes may require more quality sleep than non-athletes.

METHODS

A total of 338 (elite n = 115, 74 males and 41 females, aged 23.44 ± 4.91 years; and sub-elite n = 223, 129 males and 94 females aged 25.71 ± 6.27) athletes were recruited from a variety of team and individual sports to complete a battery of previously validated and reliable widely used questionnaires assessing sleep, recovery and nutritional practices.

RESULTS

Poor sleep was reported by both the elite and sub-elite athlete groups (i.e., global PSQI score ≥5-elite 64% [n = 74]; sub-elite 65% [n = 146]) and there was a significant difference in sport-specific recovery practices (3.22 ± 0.90 vs. 2.91 ± 0.90; p < 0.001). Relatively high levels of fatigue (2.52 ± 1.32), stress (1.7 ± 1.31) and pain (50%, n = 169) were reported in both groups. A range of supplements were used regularly by athletes in both groups; indeed, whey (elite n = 22 and sub-elite n = 48) was the most commonly used recovery supplement in both groups. Higher alcohol consumption was observed in the sub-elite athletes (12%, n = 26) and they tended to consume more units of alcohol per drinking bout.

CONCLUSION

There is a need for athletes to receive individualised support and education regarding their sleep and recovery practices.

The Sleep of Elite Australian Rules Footballers During Preseason: A Comparison of Men and Women

PURPOSE

Australian football has elite men's (Australian Football League; AFL) and women's (Australian Football League Women's; AFLW) competitions. This study compared AFL and AFLW players' sleep and characterized players' sleep in the context of current sleep recommendations.

METHODS

A total of 70 players (36 AFL, 34 AFLW) had their sleep monitored via actigraphy over a 10-day preseason period. Sleep outcomes and their intraindividual variation, were compared between AFL and AFLW players using linear mixed models. Proportions of players sleeping ≥7 and ≥8 hours per night, and achieving ≥85% sleep efficiency, were compared using chi-square analyses.

RESULTS

Compared with AFL players, AFLW players slept less (7.9 [0.5] vs 7.1 [0.6] h, P = .000), had lower sleep efficiency (89.5% [2.8%] vs 84.0% [4.4%], P = .000), and greater intraindividual variation in sleep efficiency (3.1% [0.9%] vs 5.1% [2.1%], P = .000). A total of 47% of AFLW versus 3% of AFL players averaged <7 hours sleep (χ2 = 18.6, P = .000). A total of 88% of AFLW versus 50% of AFL players averaged <8 hours sleep (χ2 = 11.9, P = .001). A total of 53% of AFLW versus 14% of AFL players averaged <85% sleep efficiency (χ2 = 12.1, P = .001).

CONCLUSIONS

AFLW players slept less and had poorer sleep quality than AFL players. Many AFLW players do not meet current sleep duration or sleep quality recommendations. Research should test strategies to improve sleep among Australian rules footballers, particularly among elite women.

Managing Travel Fatigue and Jet Lag in Athletes: A Review and Consensus Statement

Athletes are increasingly required to travel domestically and internationally, often resulting in travel fatigue and jet lag. Despite considerable agreement that travel fatigue and jet lag can be a real and impactful issue for athletes regarding performance and risk of illness and injury, evidence on optimal assessment and management is lacking. Therefore 26 researchers and/or clinicians with knowledge in travel fatigue, jet lag and sleep in the sports setting, formed an expert panel to formalise a review and consensus document. This manuscript includes definitions of terminology commonly used in the field of circadian physiology, outlines basic information on the human circadian system and how it is affected by time-givers, discusses the causes and consequences of travel fatigue and jet lag, and provides consensus on recommendations for managing travel fatigue and jet lag in athletes. The lack of evidence restricts the strength of recommendations that are possible but the consensus group identified the fundamental principles and interventions to consider for both the assessment and management of travel fatigue and jet lag. These are summarised in travel toolboxes including strategies for pre-flight, during flight and post-flight. The consensus group also outlined specific steps to advance theory and practice in these areas.

A critical review on sleep assessment methodologies in athletic populations: factors to be considered

A growing body of research focus on athletes' sleep in order to investigate the effects of sleep in sports performance and recovery or the prevalence of sleep disorders in athletes. At the same time, several sleep monitoring tools have been developed and used in athletic populations for fulfilling these purposes. This review aimed to provide critical assessment to the most used by athletes' methodological approaches and compared them with the gold standard approach. Advantages and disadvantages of the various sleep monitoring tools were critically discussed. Literature related to aspects of athletes' sleep was reviewed. From the shortlisted studies, several factors that seem to affect sleep in athletes were identified using objective methods such as polysomnography/electroencephalography and actigraphy. These factors were associated to sleep (eg such as sleep environment, familiarization procedures and napping) and daily habits (eg nutrition, fluid consumption, alcohol and caffeine intake, tobacco use). The selected studies that evaluated sleep objectively were screened according the reporting rates of these variables. The majority of the screened studies were found to underreport these variables. Practical issues were addressed and recommendations about reporting sleep-related factors were made in order to improve studies' quality assessment and allow for more robust comparisons between studies.

Effect of an Innovative Mattress and Cryotherapy on Sleep after an Elite Rugby Match

INTRODUCTION

This study aimed to explore the relationship between elite rugby union match and postmatch sleep architecture and to investigate the effects of a high-heat capacity mattress (MAT) and a whole-body cryotherapy (WBC) session on postmatch sleep architecture.

METHODS

Nineteen elite male U23 rugby union players performed in three official matches, followed by three experimental conditions, in a randomized order: MAT, WBC, and no intervention (CONT). Match load was evaluated using GPS trackers and video analyses. Sleep architecture was assessed by polysomnography (PSG). Core body temperature (CBT) and mattress surface temperature were monitored during sleep. Linear mixed-effects models were conducted to assess the effects of each experimental condition on sleep, with match load variables as covariates.

RESULTS

A lower wake after sleep onset (β = -10.5 min, P < 0.01) and higher rapid eye movement sleep proportion (β = +2.8%, P < 0.05) were reported for MAT compared with CONT. Moreover, lower mean CBT (β = -0.135°C, P < 0.001) and mean mattress surface temperature (β = -2.736°C, P < 0.001) during sleep were observed for MAT compared CONT. WBC did not affect nocturnal CBT nor interfere with sleep architecture. For every 100-m increase in high-speed running distance, a higher slow wave sleep (β = +1.1%, P = 0.05) and lower light sleep proportion (β = -1.2%, P < 0.05) proportion were observed. Conversely, for every 10 supplementary collisions, lower slow wave sleep (β = -1.9, P = 0.09) and higher light sleep (β = +2.9%, P < 0.001) proportion were observed.

CONCLUSION

MAT use had a positive effect on sleep architecture after an elite rugby union match, potentially through a more efficient nocturnal heat transfer.

Sleep and Athletic Performance: Impacts on Physical Performance, Mental Performance, Injury Risk and Recovery, and Mental Health

Research has characterized the sleep of elite athletes and attempted to identify factors associated with athletic performance, cognition, health, and mental well-being. Sleep is a fundamental component of performance optimization among elite athletes, yet only recently embraced by sport organizations as an important part of training and recovery. Sleep plays a crucial role in physical and cognitive performance and is an important factor in reducing risk of injury. This article aims to highlight the prevalence of poor sleep, describe its impacts, and address the issue of sport culture surrounding healthy sleep.

Performance indicators during international rugby union matches are influenced by a combination of physiological and contextual variables

OBJECTIVES

Research has linked physiological (e.g., hormonal, affective, fatigue) outcomes to performance indicators in rugby competition, but no work has integrated and contextualised these factors within a test-match environment. We addressed this gap by monitoring 29 athletes from a training squad across eight international rugby matches.

DESIGN

Longitudinal observational study.

METHODS

Pre-match (8-9am) measures of salivary testosterone and cortisol concentrations, sleep duration, pulse rate, muscle soreness, stress, mood, and motivation were taken. Contextual factors were playing time, internal training load (ITL), test-match experience, opponent ranking, and crowd size. Performance was indexed by coach and player ratings of performance (CRP, PRP) and quantitative metrics; offloads, turnovers, runs with ball in hand (RWB), tackles, passes, and defenders beaten (DFB).

RESULTS

Morning cortisol, sleep and mood were positively related to CRP and PRP (standardised coefficient estimates from 0.17 to 0.22). Cortisol, sleep, stress, mood and motivation were associated with one (or more) of turnovers, RWB, tackles, passes and DFB (incidence rate ratio [IRR] from 0.74 to 1.40). Playing time was positively related to all quantitative performance indicators (IRR from 1.01 to 1.04) with ITL, opponent ranking, and crowd size predicting selected outputs (IRR from 0.89 to 1.15). The explanatory models varied (conditional R²=0.15-0.83) but were generally stronger with both physiological and contextual inputs.

CONCLUSIONS

Multiple physiological and contextual factors appear to contribute to player performance in international rugby competition. Measurement of these factors may guide training and management practices, a potential practical consequence but also advancing understanding from marker to causal link.