Sleep and the athlete: narrative review and 2021 expert consensus recommendations

Sleep deprivation impairs spatial cognitive processing and Alters brain connectivity in table tennis athletes

Spatial cognitive ability is critical for table tennis athletes to achieve excellent competitive performance, and sleep may be an important factor influencing this ability. This study investigated the impact of 36h sleep deprivation on the spatial cognitive processing of 20 s-level table tennis athletes, using event-related potentials and functional connectivity analysis to assess changes in cognitive resource allocation and inter-regional brain coordination before and after sleep deprivation. The results showed that sleep deprivation significantly prolonged reaction time and led to a decrease in P3 amplitude, reflecting a reduction in participants' attentional resource allocation and cognitive processing capacity. Functional connectivity analysis further revealed that β frequency band functional connectivity between the frontal and occipital regions significantly decreased after sleep deprivation, indicating reduced brain efficiency in processing spatial information. After 36 h of SD, the spatial cognitive ability of table tennis athletes was impaired. SD not only led to a reduction in the allocation of attentional resources and cognitive processing capabilities in these athletes, but also weakened functional connectivity between the frontal and occipital lobes of the brain.

Do prolonged social media use or cognitive tasks impair neuroelectric and visuomotor performance in taekwondo athletes? A randomized and controlled trial

OBJECTIVES

We aimed to compare whether: (1) social media use (SMU) would induce a similar state of mental fatigue compared to the Modified Stroop task (MST); (2) the SMU and the MST would affect neuroelectric responses; and (3) sport-specific visuomotor performance in the taekwondo (TKD) athletes was impaired by mental fatigue.

METHODS

Fifteen TKD athletes underwent a 60-min Modified Stroop Task (MST), engaged in SMU, or watched a documentary (CON) in a randomized order. Pre and post-each conditions they responded to a Stroop task (ST) while the event-related potentials (ERP) were measured. The Visual Analogue Scale for mental tiredness (VAS-MT) was used to measure subjective feelings of mental fatigue Then, the athletes completed TKD-specific visuomotor tests.

RESULTS

The VAS-MT response increases progressively in the MST condition (p < 0.001). The response time of ST was slower in the MST than in SMU (p = 0.04). The accuracy dropped in MST comparing pre- and post-manipulation (p < 0.001) and was lower than post-CON (p = 0.005). The peak amplitude for N200 ERP was higher post-than pre for all conditions (p < 0.001) on the Fz channel. N200 amplitude was higher on CON than MST on post-manipulation (p = 0.02). The amplitude increased significantly from pre-to post in the CON condition (p = 0.009) on the Cz channel. There was no difference in visuomotor performance among conditions (all ps > 0.05).

CONCLUSION

Prolonged performance of the MST, but not SMU, induces a state of mental fatigue. Neuroelectric and cognitive responses were impaired by mental fatigue induced by MST, but the visuomotor performance remained unaffected by any condition.

Warning Signs, Monitoring Tools, and Actions Taken by World-Class Endurance Coaches in Cases of Underperformance

PURPOSE

To describe warning signs, monitoring tools, and training- and non-training-related actions taken by world-class endurance coaches in cases of underperformance.

METHODS

Twelve highly acclaimed male Norwegian coaches known for coaching world-class endurance athletes with a remarkable collection of over 350 Olympic, World, and European Championship medals-primarily with Norwegian athletes-participated in the study. Data collection and analyses followed a 3-step pragmatic qualitative study design, including an initial questionnaire, in-depth interviews, and structured negotiation between researchers and coaches.

RESULTS

Reduced performance levels and discrepancies between external (speed or power output) and internal (heart rate, lactate concentrations, and rating of perceived exertion) training-intensity measures in competitions, key training sessions, and testing scenarios, as well as observed changes in emotional state and coach-athlete communication, were highlighted as early warning signs of underperformance. Consistently, daily follow-up, systematic use of training diaries, training-intensity measures, and information from testing scenarios were rated as the most important monitoring tools in both detection and management of underperformance. In cases of underperformance, ruling out medical conditions as underlying causes was followed by a decreased training load (intensity and volume) and actions to reduce life stress to restore athletes' performance levels.

CONCLUSIONS AND PRACTICAL APPLICATIONS

The presented data collectively propose applying both objectively and subjectively measured monitoring tools and systems to the early detection and management of underperformance in endurance athletes. In addition, this should be complemented by the holistic and observational role of the coach.

Comparison of 1-hour floatation-REST versus conventional napping on heart rate variability in active individuals

Objectives

This study aimed to investigate the short-term effects of a 1-hour floatation-resting environmental therapy (FLO) versus conventional napping (NAP) on heart rate variability (HRV) in highly trained individuals.

Methods

20 non-fatigued participants underwent a prospective randomised interventional study comparing the impacts of FLO and NAP on both supine and standing HRV. Measurements were taken before and after each intervention under controlled conditions, and subjective experiences were assessed through questionnaires.

Results

FLO and NAP were associated with changes in HRV parameters but did so differently. NAP significantly enhanced supine parasympathetic activity, as evidenced by increased log-transformed root mean square of successive differences (p=0.02) and power spectral density (p=0.03) relative to heart rate (HR) values, confirming its effectiveness in promoting autonomic recovery. In contrast, despite being better perceived regarding subjective well-being (p=0.04), FLO conferred no significant changes in supine root mean square of successive differences and decreased power spectral density relative to HR (p=0.02). However, post-intervention comparisons were not statistically different. While supine HR decreased significantly following both interventions, standing HR measurements showed a non-significant increase for FLO compared with NAP (p=0.056).

Conclusion

In highly trained individuals, FLO and NAP demonstrated minimal impact on acute autonomic function. NAP appears more effective for enhancing short-term parasympathetic activity, while FLO provides a more enjoyable experience. These findings underscore the importance of personalised recovery strategies and emphasise the need for further research into individual responses and the long-term effects of these interventions.

Energy intake, hydration status, and sleep of world-class male archers during competition

BACKGROUND

Nutritional intake and sleep, play an important role for recovery and performance in elite sport but little work has been undertaken in archery. The present study aimed to assess energy intake (EI), hydration status, and sleep parameters in world-class male archers over the course of a four-day competition.

METHODS

Results, Conclusions Six male, elite-standard archers participated in the study and measurements of hydration status, EI, competition load, and sleep were recorded throughout each day of competition.

RESULTS

Daily energy, carbohydrate, and protein intake ranged between 2,563 and 3,986 kcal, 4 and 7.1 g/kg BM, 2.2 and 3.6 g/kg BM per day, respectively. Thus, archers practiced elements of periodized nutrition such that energy and carbohydrate intake was greater on the high-volume competition days (i.e. days 1 and 3; more numbers of arrows, longer duration, and walking distance) in comparison to low-volume days (days 2 and 4) over the tournament (all p > 0.01). Additionally, urine specific gravity was higher after waking, compared to pre- and post-competition, and before bed (all p < 0.05). This indicates that archers were euhydrated pre- and post-competition and before bedtime, while they were slightly hypohydrated after waking up. Sleep data show that disturbances were kept to a minimum.

CONCLUSIONS

Collectively, archers appear capable of periodizing their nutritional intake according to daily physical loading during a tournament whilst, staying euhydrated and maintaining sleep quality. In part, such data can help to explain why these archers experience a sustained level of success.

Influence of Menstrual-Cycle Phase on Sleep and Recovery Following High- and Low-Intensity Training in Eumenorrheic Endurance-Trained Women: The Female Endurance Athlete Project

PURPOSE

To investigate the influence of menstrual-cycle (MC) phase on objective sleep and perceived recovery following high- (HIT) and low-intensity training (LIT) in endurance-trained women.

METHODS

Fifteen naturally menstruating, endurance-trained women completed standardized HIT and LIT sessions during the early follicular phase (EFP), ovulatory phase (OP), and midluteal phase (MLP) of 2 MCs. Overnight sleep was monitored using a Somnofy sleep monitor after each training session, and perceived recovery was assessed after 24 hours using self-report scales. MC phases were determined using the 3-step method, and noneumenorrheic MCs were retrospectively excluded from analysis.

RESULTS

MC phase had a main effect on wake after sleep onset (P ≤ .001), with higher values in MLP (33 [22] min) than EFP (22 [19] min, P = .043) and OP (14 [9] min, P = .001), sleep efficiency (P = .033), with lower values in MLP (87% [6%]) than OP (90% [8%], P = .047), and light sleep (P = .023) with higher values in MLP (59% [6%]) than EFP (54% [7%], P = .037). Session type had a main effect on perceived recovery (P < .018) and perceived muscle soreness (P = .007), indicating lower perceived recovery and higher perceived muscle soreness following HIT compared to LIT (P < .001, P = .018, respectively). No interactions were found between MC phase and session type for any of the measured variables.

CONCLUSIONS

Objective sleep quality, but not perceived recovery, was influenced by MC phase, as indicated by small impairments to multiple indices of objective sleep during MLP. There were no interactions between MC phase and session type, indicating that the effect of MC on sleep and recovery is consistent regardless of session type.

Influence of short-term chronic oral cannabidiol application on muscle recovery and performance after an intensive training protocol - a randomized double-blind crossover study

BACKGROUND

Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application.

METHODS

A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used.

RESULTS

It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed.

CONCLUSION

It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

Did social isolation affect anxiety and sleep quality of elite soccer players during the COVID-19 lockdown? Comparisons to training before distancing in the pandemic and outlook for mental health

Objective

To analyze the anxiety levels and sleep quality of elite soccer athletes in training pre-pandemic and during the lockdown caused by COVID-19.

Method

This is an exploratory study with a longitudinal design carried out with elite soccer athletes from two Brazilian soccer clubs. Data collection took place in person pre-pandemic (training) and online (during lockdown) between February and May 2020. The instruments used to assess sleep, daytime sleepiness, and anxiety were the Pittsburgh Sleep Quality Index (PSQI), Epworth Daytime Sleepiness Scale-(ESS-BR), and Competitive Anxiety Scale (SCAT). For data analysis, descriptive statistics (frequencies, percentages, maximum and minimum) and non-parametric inferential statistics were used, establishing a significance of p < 0.05.

Results

In total, 76 male soccer athletes participated in the study. A significant increase was observed in anxiety levels in confinement compared to pre-pandemic training (p = 0.017; g = 0.83), and sleepiness significantly reduced in training compared to baseline levels (p = 0.007; g = 0.48). The athletes demonstrated good sleep quality and the pandemic did not significantly alter daytime sleepiness compared to training and baseline.

Conclusion

From the results it can be concluded that elite soccer athletes presented alterations in anxiety levels compared to training during confinement, however, no effects of confinement were observed on sleep quality and sleepiness. New studies are needed to analyze the long-term consequences of the pandemic and the relationships between anxiety and sleep in training and competition in athletes.

The relationship between sleep, pain,and musculoskeletal injuries in US Army Soldiers

INTRODUCTION

The purpose of this study was to investigate the relationship between sleep and pain in military personnel and to determine if metrics of sleep and pain intensity differ between the injured and uninjured in this population.

METHODS

Active-duty US Army Soldiers (n=308; 26.8±6.5 years, 82% male) from the 2nd Infantry Division, Joint Base Lewis-McChord, Washington, and 101st Airborne Division, Fort Campbell, Kentucky, completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and questionnaires about current musculoskeletal injuries and pain intensity (0=no pain to 10=worst imaginable pain). Pearson correlation coefficients were used to assess the association between pain and sleep. Differences in sleep and pain between injured and uninjured participants were determined using an analysis of covariance.

RESULTS

Pain intensity was positively correlated with sleep quality (global PSQI score, r=0.337, p<0.001) and daytime sleepiness (ESS score, r=0.163, p=0.005), and negatively associated with sleep duration (r=-0.118, p=0.039). Injured participants accounted for 37.7% (n=116) of the study population. Injured participants reported greater pain intensity (3.7±2.5 vs 1.3±1.9, p<0.001), were older (28.5±7.4 years vs 25.8±5.7 years, p=0.001) and in the service longer (6.3±6.3 years vs 4.6±4.7 years, p=0.013) than uninjured participants. Injured participants had higher global PSQI scores (9.0±4.1 vs 6.4±3.4, p<0.001), including each of the seven PSQI components (all p<0.050), and reported sleeping less per night than uninjured participants (5.7±1.3 hours vs 6.1±1.2 hours, p=0.026).

CONCLUSION

These data demonstrate that pain intensity is associated with sleep in active-duty US Army Soldiers and that those who report a musculoskeletal injury, regardless of age and time in service, report poorer sleep quality, shorter sleep durations, and greater levels of pain than uninjured Soldiers.

Knowledge About Sleep, Sleep Hygiene, and Sleep Behaviors of Paralympic Athletes

CONTEXT

Understanding Paralympic athletes' perspectives on the importance of sleep is the first step toward developing effective sleep hygiene (SH) strategies. We aim to describe and compare the knowledge about SH and sleep behaviors practiced by medalists and nonmedalists Paralympic athletes at the Tokyo 2020 Paralympic Games and between sexes (female vs male), identify whether the coaching staff encourages SH, and the perspective of these athletes on the importance of SH.

METHODS

98 Paralympic athletes responded to the Sleep Beliefs Scale and the Athlete Sleep Behavior Questionnaire-BR.

RESULTS

Medalists (68%) and nonmedalists (78%) Paralympic athletes had low knowledge about SH (60% vs 55%; P = .20), with no difference between groups. The Athlete Sleep Behavior Questionnaire-BR score (48.7 [5.9]) for all Paralympic athletes (n = 98) indicated high practice of maladaptive sleep behaviors. Male athletes had significantly worse sleep behaviors than female athletes (49.1 [6.0] vs 39.5 [7.2]; P < .01) and less knowledge about behaviors that can affect sleep (64% vs 72%; P < .05), 26% of Paralympic athletes considered SH practices necessary, and the frequency of coaching staff encouraging SH was higher among medalists Paralympic athletes compared to nonmedalists athletes (29% vs 13%, P = .04).

CONCLUSIONS

Most Paralympic athletes have inadequate sleep behaviors and knowledge about SH. There was no difference between knowledge about SH and sleep behaviors between medalists and nonmedalists Paralympic athletes, although medalists athletes were more encouraged to practice SH. Male Paralympic athletes had worse sleep behaviors and worse knowledge about SH than female athletes.

The effect of a 2-week ischaemic preconditioning intervention on anaerobic performance in male academy football players: a randomized, single-blinded, SHAM-Controlled study

Ischaemic preconditioning (IPC), brief periods of ischaemia immediately followed by reperfusion applied to a vascular bed, has emerged as a method to improve exercise performance. There is, however, a lack of research exploring repeated episodes of IPC on anaerobic performance. The aim of this study was to determine if a 2-week repeated IPC intervention could enhance anaerobic performance in male academy football players. Eight male academy football players completed two, 2-week intervention trials: six IPC episodes (4 × 5 min at 220 mmHg per episode), and six SHAM episodes (4 × 5 min at 20 mmHg per episode). Prior to and following each intervention trial, the participants completed assessments of anaerobic performance (Running Anaerobic Sprint Test [RAST]), and superficial femoral artery endothelial function (flow-mediated dilation [FMD]). IPC significantly enhanced peak and mean power output by 12% (p = 0.026) and 11% (p = 0.019) and significantly improved superficial femoral artery FMD (p = 0.049). The increase in endothelial function suggests that this may be a mechanism contributing to this enhancement of anaerobic performance. The present study supports the use of repeated IPC prior to matches and training sessions to enhance anaerobic performance.

Behavioral interventions and behavior change techniques used to improve sleep outcomes in athlete populations: A scoping review

BACKGROUND

Athletes display a high prevalence of undesired sleep characteristics that may affect both performance and wellbeing.

OBJECTIVES

This scoping review aimed to identify and map the existing evidence of behavioral sleep interventions and their effects on sleep outcomes in athletes, and retrospectively code the behavior change techniques (BCTs) implemented using the Behavior Change Technique Taxonomy (BCTTv1).

METHODS

Conducted following the JBI methodology for scoping reviews, four online databases were used to identify prospective interventions with at least one behavioral component in competitive athletes, and reporting a sleep outcome pre- and post-intervention.

RESULTS

Thirty-three studies met the inclusion criteria, encompassing 892 participants with a median age of 23. Five intervention categories were identified (education, mind-body practices, direct, multi-component, and other), with each demonstrating mixed efficacy but the potential to improve sleep outcomes. The BCTs varied in type and frequency between each category, with only 18 unique BCTs identified across all studies.

CONCLUSIONS

The varied efficacy of previous studies at improving sleep outcomes may be attributed to the lack of behavior change theory applied during intervention development. Designing interventions following a targeted specification of the behavioral problem, and the integration of corresponding BCTs should be considered in future research.

Does Relative Energy Deficiency in Sport (REDs) Syndrome Exist?

Relative energy deficiency in sport (REDs) is a widely adopted model, originally proposed by an International Olympic Committee (IOC) expert panel in 2014 and recently updated in an IOC 2023 consensus statement. The model describes how low energy availability (LEA) causes a wide range of deleterious health and performance outcomes in athletes. With increasing frequency, sports practitioners are diagnosing athletes with "REDs," or "REDs syndrome," based largely upon symptom presentation. The purpose of this review is not to "debunk" REDs but to challenge dogmas and encourage rigorous scientific processes. We critically discuss the REDs concept and existing empirical evidence available to support the model. The consensus (IOC 2023) is that energy availability, which is at the core of REDs syndrome, is impossible to measure accurately enough in the field, and therefore, the only way to diagnose an athlete with REDs appears to be by studying symptom presentation and risk factors. However, the symptoms are rather generic, and the causes likely multifactorial. Here we discuss that (1) it is very difficult to isolate the effects of LEA from other potential causes of the same symptoms (in the laboratory but even more so in the field); (2) the model is grounded in the idea that one factor causes symptoms rather than a combination of factors adding up to the etiology. For example, the model does not allow for high allostatic load (psychophysiological "wear and tear") to explain the symptoms; (3) the REDs diagnosis is by definition biased because one is trying to prove that the correct diagnosis is REDs, by excluding other potential causes (referred to as differential diagnosis, although a differential diagnosis is supposed to find the cause, not demonstrate that it is a pre-determined cause); (4) observational/cross-sectional studies have typically been short duration (< 7 days) and do not address the long term "problematic LEA," as described in the IOC 2023 consensus statement; and (5) the evidence is not as convincing as it is sometimes believed to be (i.e., many practitioners believe REDs is well established). Very few studies can demonstrate causality between LEA and symptoms, most studies demonstrate associations and there is a worrying number of (narrative) reviews on the topic, relative to original research. Here we suggest that the athlete is best served by an unbiased approach that places health at the center, leaving open all possible explanations for the presented symptoms. Practitioners could use a checklist that addresses eight categories of potential causes and involve the relevant experts if and when needed. The Athlete Health and Readiness Checklist (AHaRC) we introduce here simply consists of tools that have already been developed by various expert/consensus statements to monitor and troubleshoot aspects of athlete health and performance issues. Isolating the purported effects of LEA from the myriad of other potential causes of REDs symptoms is experimentally challenging. This renders the REDs model somewhat immune to falsification and we may never definitively answer the question, "does REDs syndrome exist?" From a practical point of view, it is not necessary to isolate LEA as a cause because all potential areas of health and performance improvement should be identified and tackled.

Snooze it or Lose it: Understanding Sleep Disturbance and Injuries in Soccer and Basketball Student-Athletes

OBJECTIVES

To assess the sleep characteristics of collegiate soccer and basketball student-athletes and explore the associations between sleep and injury risk.

DESIGN

Cohort study.

SETTING

NCAA D1 and NAIA Tier 1.

PARTICIPANTS

One hundred eighty-one collegiate soccer and basketball student-athletes (42% female; mean age: 20.0 ± 1.7 years).

INDEPENDENT VARIABLES

Questionnaires were administered during the 2020/2021 and 2021/2022 preseason, collecting demographic, injury history, medical history, and sleep information, including sleep difficulty category scores of 0 to 4 (none), 5 to 7 (mild), and ≥8 (moderate/severe) and other sleep disturbance measures derived from the Athlete Sleep Screening Questionnaire (ASSQ), including insufficient sleep duration (<7 hours of sleep) and poor subjective sleep quality.

MAIN OUTCOME MEASURES

All-complaint knee and ankle injuries.

RESULTS

According to the ASSQ, 25.4% (95% confidence interval [CI], 17.9-34.3) of the student-athletes had mild sleep difficulty and 12.7% (95% CI, 7.3-20.1) had moderate/severe sleep difficulty. 36.1% (95% CI, 29.1-43.6) had insufficient sleep duration. 17.1% (95% CI, 11.7-23.7) were not satisfied with the quality of their sleep (poor sleep quality), and 13.8% (95% CI, 9.1-19.7) had an "eveningness" chronotype. Based on multivariable logistic regression models, student-athletes with poor sleep quality had significantly higher odds for injury (OR: 2.2, 95% CI, 1.04-4.79, P = 0.039).

CONCLUSIONS

Clinically relevant dysfunctional sleep patterns are prevalent among collegiate soccer and basketball student-athletes. Poor sleep quality was significantly associated with injury risk among student-athletes. Findings suggest a substantial sleep problem in collegiate soccer and basketball student-athletes and warrant that student-athletes are regularly screened and timely interventions applied.

The acute effects of nonsleep deep rest on perceptual responses, physical, and cognitive performance in physically active participants

This study aimed to examine the effect of nonsleep deep rest (NSDR) on physical and cognitive performance, as well as sleepiness, acute readiness, recovery, stress, and mood state in physically active participants. A total of 65 physically active participants (42 male, 23 female) were randomly assigned into two groups: an experimental group (NSDR, n = 34), in which participants completed a 10-min NSDR intervention, and a control group (CON, n = 31), whereby participants sat passively for 10 min. Testing measures were assessed immediately pre and 10 min post each condition and comprised completing a hand grip strength dynamometer test and a countermovement jump test on force plates, cognitive function measures via a psychomotor vigilance task (PVT-B), and a Simon task test, along with four questionnaires to assess sleep, recovery, and mood state. A significant Group × Time interaction favored the NSDR condition for handgrip strength, median reaction time during the PVT-B, and accuracy percentage during the Simon task. Questionnaire responses demonstrated NSDR to be associated with significant benefits to physical readiness, emotional balance, overall recovery, negative emotional state, overall stress, and tension in comparison to CON (p < .05). The NSDR intervention could be a valuable strategy for acutely enhancing overall well-being and readiness.

Chronotype, sleep hygiene, and sleep characteristics among athletes of different disciplines

The objective of the study was to assess chronotype, sleep hygiene, and sleep characteristics of Italian athletes in order to identify differences among sport disciplines (team- vs individual-sports), level of competition (Elite vs Non-Elite) and sexes. Moreover, correlations between chronotype, sleep hygiene and sleep quality were evaluated. Two hundred eighty Italian athletes (Females:113; Males:167) participated in the study. They completed the Pittsburgh Sleep Quality Index (PSQI), the Sleep Hygiene Index (SHI) and the MorningnessEveningness Questionnaire (MEQ). Among the athletes, 66.4% were intermediate-type, 21.8% were morning-type and 11.8% were evening-type. 55.4% of the sample was classified as good sleeper (PSQI<5), while 16.1% had poor sleep hygiene (SHI≥35). Females had higher total sleep time (p=0.022) than males. Individual-sports showed more morning-oriented score (p=0.001) and lower PSQI (p=0.006) and SHI (p<0.001) scores, with earlier timing of sleep (bedtime:p<0.001; wake-up time:p<0.001) compared to teamsports. Elite athletes exhibited greater sleep efficiency (p=0.009), and lower sleep latency (p=0.018) and wake after sleep onset (p=0.043) than Non-Elite athletes. Additionally, significant correlations were found between PSQI and SHI (r=0.43, p<0.001), and between MEQ and SHI (r=-0.35, p<0.001). This study yields crucial insights into the sleep behaviors of Italian athletes, revealing that nearly half of the sample were bad sleepers.

Gaelic Games Players' and Practitioners' Perceptions of Recovery Strategies

PURPOSE

This study both investigated and compared Gaelic games players' and practitioners' perceptions of the importance of postexercise recovery strategies.

METHODS

Gaelic players (n = 1178 [n = 574 female], age 24.6 [6.6] y) and practitioners (n = 148 [n = 29 female], age 35.9 [8.7] y) completed a questionnaire assessing their perceptions of various postexercise recovery strategies (importance ranked out of 5 [1 "not important at all" to 5 "extremely important"]). Players were further categorized by playing standard into developmental (club/collegiate; n = 869) and national (intercounty; n = 309) levels and by sport: Gaelic football (n = 813), camogie/hurling (n = 342), and Gaelic handball (n = 23). Practitioners were categorized as sport coaches (n = 67), strength and conditioning staff (n = 34), nutrition staff (n = 15), and athletic rehabilitation staff (n = 32).

RESULTS

Gaelic players prevalently perceived sleep (76.4%), rehydration (72.5%), postexercise meal (48.4%), stretching (47.6%), active cool-down (25.1%), foam rolling (23.1%), and massage by therapist (22.6%) as "extremely important." Practitioners prevalently perceived sleep (90.1%), rehydration (83.6%), postexercise meal (76.6%), daytime naps (36.2%), stretching (25.4%), discussion with teammates (24.6%), and getting into nature (19.4%) as "extremely important."

CONCLUSIONS

While strategies with well-documented efficacy such as sleep, nutrition, and rehydration were rated as most important, a distinct and possibly problematic disconnect exists between the perceived importance of many strategies and their empirically demonstrated effectiveness. For instance, active cool-downs and stretching were perceived as highly important despite prevailing evidence suggesting that their effects are often small in magnitude. Collectively, work promoting optimal recovery practices and aligning player-practitioner perspectives would be beneficial to maximize time and resource allocation and enhance player buy-in.

IOC consensus statement on elite youth athletes competing at the Olympic Games: essentials to a healthy, safe and sustainable paradigm

With the pronounced ongoing growth of global youth sports, opportunities for and participation of youth athletes on the world sports stage, including the Olympic Games, are expected to escalate. Yet, adolescence is a vulnerable period of development and inherently dynamic, with non-linear and asynchronous progression of physical, physiological, psychological and social attributes. These non-concurrent changes within and between individuals are accompanied by irregular and unpredictable threats and impediments. Likewise, the evident age-based criteria and conventional path for those youth athletes deemed eligible candidates for the Olympic Games are not well or consistently defined. Furthermore, the unstructured and largely varying policies and practices across the sporting International Federations specific to youth participation underscore the need to establish a contemporary universal paradigm that would enable elite youth athletes to navigate an individualised healthy pathway to personal, athletic and sport success. First, we reviewed and summarised key challenges facing elite youth athletes and the relevant evidence fundamental to facilitating and supporting central aspects of health and well-being, while empowering safe, sustainable and positive engagement during athletic and personal advancement and competition. Second, we developed and present a modern elite youth athlete model that emphasises a child-centred, practical framework with corresponding guidelines and recommendations to protect health and well-being while safely and favourably managing international sport competition. Our proposed evidence-informed paradigm will enable and support individualised pathways for healthy, well-rounded and sustainable positive engagement while achieving sport success for youth contending or aiming to compete at world-class international sporting events.

Menstrual-Cycle Symptoms and Sleep Characteristics in Elite Soccer Players

PURPOSE

To determine whether menstrual-cycle symptoms are associated with sleep in elite female athletes.

METHODS

Sleep was assessed for a minimum of 25 nights (range = 25-31) using activity monitoring and sleep diaries. Menstrual-cycle symptoms were collected over the same duration in 12 elite female professional soccer players. Generalized estimating equations were used to examine the relationship between the day of the menstrual cycle (from day 1) and total menstrual-cycle symptoms on sleep characteristics.

RESULTS

There was a significant relationship between sleep duration and the day of the menstrual cycle (P = .042) and total symptoms reported that day (P < .001), with sleep duration increasing by 21 minutes for every symptom reported. There was a negative day × symptom interaction on sleep duration (P = .004), indicating that with increased symptoms, the day of the menstrual cycle had a smaller relationship with sleep duration. Sleep efficiency (P = .950), wake after sleep onset (P = .217), and subjective sleep quality (P = .080) were not related to the day of the menstrual cycle. The total symptoms reported had no relationship with sleep efficiency (P = .220), subjective sleep quality (P = .502), or sleep latency (P = .740) but did significantly relate to wake after sleep onset (P < .001), with a significant day × symptom interaction (P < .001).

CONCLUSIONS

Sleep duration increased from day 1 of the menstrual cycle and was associated with the number of menstrual-cycle symptoms reported. All other sleep metrics remained unchanged; however, total symptoms reported were related to wake after sleep onset. Monitoring and managing menstrual-cycle symptoms should be encouraged due to a potential relationship with sleep characteristics.

The Sleep Parameters of Olympic Athletes: Characteristics and Assessment Instruments

This systematic review aims to identify the sleep parameters of Olympic athletes and the instruments used to assess and monitor the sleep of these athletes. The search was conducted until February 2023 and was performed in PubMed, Web of Science, and Scopus databases. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), awakenings after sleep onset (WASO), quality of sleep, daytime sleepiness, and chronotype; the participants were Olympic athletes. The search returned a total of 280 studies. After screening based on exclusion and inclusion criteria, 11 studies were included. The main results demonstrate that Olympic athletes have TST of 06:10 h, SE of 84%, SOL of 28 min, and WASO of 49 min. The most predominant chronotype is indifferent; over half of the athletes have poor sleep quality and complaints. Furthermore, actigraphy was the most used method to assess sleep. It is concluded that Olympic athletes have TST, SE, and WASO poor than the recommended values. In addition, sleep complaints and poor sleep quality were also observed. Among the objective sleep assessment methods, actigraphy was the method most frequently used in this population.

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.

Higher Levels of Morning and Daytime Light Exposure Associated with Positive Sleep Indices in Professional Team Sport Athletes

Objective

Light exposure techniques have been recommended to combat sleep issues caused by disruption to circadian regularity in the athletic population, although studies are lacking.

Methods

A total of 17 professional male Australian Football athletes (age ± SD: 22 ± 3 years) wore a wrist actigraph to measure sleep parameters, and a wearable light sensor to measure melanopic equivalent daylight illuminance (mEDI, in lux) for 14 days. Participants completed three sleep questionnaires at the end of the data collection period and completed well-being surveys 6 times. The Sleep Regularity Index (SRI) for each player was also calculated from actigraphy data. Light exposure data were organised into three different timeframes: morning (wake time + 2 hours), daytime (end of morning to 6 pm), and evening (2 hours leading up to bedtime) for analysis. Repeated measures correlation was conducted for objective sleep measures and mEDI values per timeframe. Pearson's correlation was conducted on subjective sleep measures and well-being measures against mEDI values per timeframe.

Results

Higher morning light was associated with significantly (p < 0.001) greater total sleep time (r = 0.31). Higher daytime light exposure was associated with higher subjective sleep quality (r = 0.48, p < 0.05). Higher evening light exposure was associated with higher Athlete Sleep Screening Questionnaire (ASSQ) global scores (r = 0.52, p < 0.05). There were no other significant correlations between light exposure and sleep or well-being measures (p > 0.05).

Conclusion

Higher morning and daylight exposure levels were associated with various positive objective and subjective sleep measures in professional team sport athletes, supporting the need for education on optimising light exposure to improve circadian function, sleep, and health.

Are Adolescent Athletes Sleeping Enough? An Observational Study of Sleep Parameters during Schooldays and Holidays

Background: Inconsistent sleep schedules, frequent awakening after sleep onset (WASO), and decreased sleep efficiency (SE) are common issues among adolescent team sports athletes. Moreover, research indicates that sleep problems are enhanced across schooldays. The aim of the present study was to assess sleep patterns of adolescent athletes and compare sleep parameters between schooldays and holidays. Methods: The chronotype and sleep quality of twelve adolescent basketball players (mean age: 15.58 ± 0.67 years) were assessed. Objective sleep parameters were then analyzed using actigraphy over a 12-day period, which included six days during the school period and six days during holidays. Results: Data showed that total sleep time (TST), SE, and WASO (382.48 min, 81.81%, and 66.70 min, respectively) did not meet international recommendations for sleep quantity and quality. During school weekdays, time in bed (TIB), TST, and SE significantly decreased compared to weekends (p < 0.001, d = -1.49; p < 0.001, d = -1.64; and p = 0.01, d = -0.89, respectively). On weekdays, TIB, TST, and WASO were significantly lower on schooldays compared to holidays (p < 0.001, d = -1.83; p < 0.01, d = -1.01; and p = 0.02, d = -0.77, respectively). While no significant difference was observed in social jetlag, the mid-point of sleep was significantly later on holiday weekdays compared to school weekdays (p < 0.05, d = 0.65). Conclusions: Adolescent athletes experience insufficient sleep, especially on school weekdays, which is partially improved during weekends and holidays. Although sleep duration was longer during holidays, our results suggest that adolescent athletes' sleep was more fragmented. Consequently, it remains crucial to implement strategies to enhance their sleep health (e.g., napping).

Increased training load promotes sleep propensity and slow-wave sleep in endurance runners: Can a high-heat-capacity mattress topper modulate this effect?

The present study aimed to: (1) investigate sleep architecture in response to an overload training and taper periods among endurance runners; and (2) assess the sleep benefits of a high-heat-capacity mattress topper. Twenty-one trained male endurance runners performed a 2-week usual training regimen (baseline) followed by 2-week overload and taper periods. From overload to the end of the taper period, they were assigned into two groups based on the mattress topper used: high-heat-capacity mattress topper (n = 11) or low-heat-capacity mattress topper (n = 10). Training load was assessed daily using the session rating of perceived exertion. Following each period, sleep was monitored by polysomnography, and nocturnal core body temperature was recorded throughout the night. Irrespective of the group, awakening episodes > 5 min decreased following overload compared with baseline (-0.48, p = 0.05). Independently of mattress topper, each 100 A.U. increase in 7-day training load prior to polysomnographic recording was associated with higher slow-wave sleep proportion (β = +0.13%; p = 0.05), lower sleep-onset latency (β = -0.49 min; p = 0.05), and a reduction in the probability of transition from N1 sleep stage to wakefulness (β = -0.12%; p = 0.05). Sleeping on a high-heat-capacity mattress topper did not affect any sleep variable compared with a low-heat-capacity mattress topper. Increased training loads promote slow-wave sleep and sleep propensity, highlighting the adaptative nature of sleep to diurnal activity and the role of sleep in physiological recovery. Further studies are required on the potential benefits of high-heat-capacity mattress toppers on sleep architecture among athletes.

Sleep and lucid dreaming in adolescent athletes and non-athletes

During lucid dreaming (LD), dreamers are aware of experiencing a dream and may consciously influence its content. This study used an online questionnaire to investigate the LD frequency and applications in 193 adolescent athletes and non-athletes (17.40 ± 2.09 years; 46% athletes, 54% controls). Given the critical role that sleep plays in adolescent health, development, and performance, associations of LD with various sleep parameters were also explored. LD is prominent in adolescents (67.4% experienced it at least once, 30.0% once a month or more, 12.9% at least once a week), but similar in terms of frequency and uses between athletes and non-athletes. A higher proportion of those who practiced sports/dance during LD reported improved waking self-efficacy (57.1%) over sport performance (42.9%). There was no indication that chronotype preference may influence LD nor that LD may be detrimental to adolescent sleep. Athletes and controls had similar sleep durations, daytime sleepiness, and sleep disturbances frequency, but athletes reported higher sleep quality. Despite, on average, meeting the minimum sleep recommendation guidelines for their age, a relatively large proportion of adolescents did not attain sufficient sleep, particularly on weeknights (47.4% 14-17 years; 20.0% 18-21 years), suggesting that restricted sleep remains prevalent in adolescent populations.

Ultramarathon runners and support crew: The influence of pre-race sleep and training profiles on performance in a 217-km mountain race

The present study evaluates the effects of pre-race sleep and training characteristics among ultra-athletes and support crew, and the influence of these factors on the athlete's performance in a 217-km ultramarathon. A total of 38 ultramarathon runners and 59 support crew members were assessed. The participants answered questionnaires about chronotype, sleep quality, sleepiness, basic demographics, and pre-race training. The clinical trial registration number is RBR-7j6d23v. The results showed that athletes and support crew had a morning-type chronotype and good sleep efficiency; most had poor-quality sleep. The athletes who finished the race had a higher sleep latency than non-finishers (p < 0.001). The quality of sleep may have impacted performance because the athletes with good sleep quality trained one day more per week than those without (p < 0.001), and training frequency was highly correlated with the race time (r = -0.59). These findings are novel, expand the data about sleep, training, and performance in an ultramarathon, and innovate by addressing the support crew.

Effects of an Acute Dose of Zinc Monomethionine Asparate and Magnesium Asparate (ZMA) on Subsequent Sleep and Next-Day Morning Performance (Countermovement Jumps, Repeated Sprints and Stroop Test)

The goal of the present study was to determine whether an acute dose of a zinc-containing nutritional supplement (ZMA) has any effects on sleep and morning performance in recreationally trained males. Nineteen males participated in a repeated-measures within-subjects study to assess objective and subjective measures of sleep, completed counter-movement jumps (CMJ) and repeated sprint morning performance (RSP). Three days of baseline food intake showed no major deficiencies of zinc, magnesium or vitamin B6 for all participants (11.9 ± 3.4, 395 ± 103 and 2.7 ± 0.9 mg.day-1, respectively). Sleep (22:30-06:30 h) was assessed via actimetry, and either a control (no tablets, NoPill), dextrose placebo (PLAC) or ZMA was ingested 30-60 min before retiring to bed for two nights. The participants undertook the three conditions (NoPill, PLAC or ZMA) administered in a counterbalanced order. The data were analyzed using general linear models with repeated measures. In healthy active males who consume diets of adequate micronutrients, sleep normally and maintain good sleep hygiene (time to bed and wake times), ZMA supplementation had no beneficial effect on RSP or performance in the Stroop test (p > 0.05) but did improve CMJ height (p < 0.001) compared to that of PLAC but not NoPill (p > 0.05). Supplementation of ZMA for two nights had no effect on sleep, RSP or cognitive function. The NoPill condition elucidated the effects of the intervention under investigation.

In Males with Adequate Dietary Needs Who Present No Sleep Disturbances, Is an Acute Intake of Zinc Magnesium Aspartate, Following Either Two Consecutive Nights of 8 or 4 h of Sleep Deprivation, Beneficial for Sleep and Morning Stroop Interference Performance?

PURPOSE

Purpose: We examined whether supplementation of zinc magnesium aspartate (ZMA) in two groups of males, either partially sleep-restricted (4 h) or with habitual sleep (8 h) for 2 nights, was beneficial for sleep and subsequent morning Stroop performance.

METHODS

Participants were randomly allocated to two independent groups who either had 4 h (33 males) or 8 h (36 males) sleep for two nights. Using a double-blinded, randomised counterbalanced design, they then completed five sessions, (i) two familiarisation sessions including 7 days of sleep and dietary intake, (ii) three conditions with 4 h or 8 h sleep and either NoPill control (NoPill), placebo (PLAC) or ZMA (ZMA). Sleep was assessed by actimetry and sleep questionnaires, and cognitive performance was assessed by the Stroop test. The data were analysed using a general linear model with repeated measures.

RESULTS

A main effect for "sleep" (4 or 8 h) was found, where more opportunity to sleep resulted in better "sleep" metrics (both objective and subjective) as well as better Stroop scores (lower colour-interference and word-interference scores and lower error in words). No main effect for "Pill" was found other than the mood state depression, where subjective ratings for the PLAC group were lower than the other two conditions. Interactions were found in anger, ease to sleep and waking time.

CONCLUSION

Having 8 h opportunity to sleep resulted in better "sleep" metrics as well as better Stroop scores compared to 4 h. Supplementation of ZMA for 4 or 8 h for 2 nights had no effect on subsequent morning cognitive performance but reduced sleep or total sleep time by ~0.46 h compared to the other conditions. An interaction was found where sleep time was reduced by ~0.94 h in the ZMA group in the 8 h condition compared to NoPill or PLAC.

Effects of Different Caffeine Dosages on Maximal Physical Performance and Potential Side Effects in Low-Consumer Female Athletes: Morning vs. Evening Administration

While previous studies have explored a range of factors governing the optimal use of caffeine (CAF) in athletes, limited research has explored how time of day (TOD) affects the ergogenic effects of various CAF dosages on physical performance. This study aimed to increase knowledge about how different recommended CAF doses (3 mg/kg vs. 6 mg/kg) ingested at different TODs affected maximal high-intensity physical performance and the perception of potential side effects in female athletes. In this double-blind, randomized, and counterbalanced study, 15 low CAF consumer athletes (aged 18.3 ± 0.5 y) underwent six trials, including three testing conditions assessed across two TODs: one in the morning (08:00 a.m.) and one in the evening (06:00 p.m.). During each condition, the participants ingested either a placebo, 3 mg/kg CAF (CAF (3 mg)), or 6 mg/kg CAF (CAF (6 mg)) capsules 60 min before each test with an in-between washout period of at least 72 h. In each trial, the participants performed a countermovement jumps test (CMJ), a modified agility t test (MATT), a repeated sprint ability (RSA), a rating of perceived exertion (RPE), and finally, a CAF side effects questionnaire. Our findings indicate the absence of an ergogenic effect on CMJ, MAT, and RSA performance in the evening after administering CAF (3 mg) or CAF (6 mg) compared to a placebo. Likewise, when CAF was ingested in the morning, there was an improvement in these performances with both CAF (3 mg) and CAF (6 mg), with greater improvement observed after CAF (6 mg). Additionally, neither the CAF dosage nor the TOD had a significant effect on the RPE. The occurrence of side effects increased significantly after the evening ingestion of CAF, particularly with a moderate dose of CAF (6 mg). Our findings indicate that the effectiveness of CAF depends on the TOD and CAF dosage. When ingested in the morning, a moderate dose of CAF (6 mg), rather than CAF (3 mg), is more effective in improving short-term physical performance without affecting CAF side effects in female athletes. Nevertheless, when ingested in the evening, neither dose was sufficient to enhance short-term physical performance, and both dosages increased the incidence of CAF side effects, particularly at a moderate dose.

Effects of Acute Sleep Deprivation on Sporting Performance in Athletes: A Comprehensive Systematic Review and Meta-Analysis

Objective

Using meta-analysis to comprehensively and quantitatively evaluate the impact of acute sleep deprivation on different sports performance of athletes, this study aims to provide scientific guidance for coaches in optimizing and adjusting training and competition arrangements.

Methods

Establishing literature inclusion and exclusion criteria, we conducted searches in both Chinese and English databases. Using stata 14.0, we analyzed 75 indicators from 27 included literature, focusing on three aspects: the impact of acute sleep deprivation on overall athletic performance, the impact on sporting performance across various athletic abilities, and the disparities in athletic performance between morning and afternoon following acute sleep deprivation.

Results

The effect size of acute sleep deprivation on overall athletic performance was -0.56 (P<0.05). Sub-analyses revealed effect sizes of -0.23 (P<0.05) for whole night sleep deprivation, -1.17 (P<0.05) for partial sleep deprivation at the end of the night, and -0.25 (P>0.05) for partial sleep deprivation in the beginning of the night. The effect sizes of acute sleep deprivation on high intensity intermittent exercise, skill control, speed, aerobic endurance, and explosive power indicators were -1.57, -1.06, -0.67, -0.54, and -0.39 respectively (P<0.05). The effect sizes of acute sleep deprivation on the overall athletic performance in the morning and afternoon were -0.30, and -1.11, respectively (P<0.05).

Conclusion

Acute sleep deprivation significantly impairs the overall athletic performance of athletes, with a more pronounced negative impact observed with partial sleep deprivation at the end of the night. Various types of exercise performance are adversely affected by acute sleep deprivation, with magnitude of impact ranking high intensity intermittent, skill control, speed, aerobic endurance, and explosive power. Following acute sleep deprivation, athletes' overall sporting performance in the afternoon is inferior to that in the morning.

The Limitations of Using the Pittsburgh Sleep Quality Index to Assess Athletes' Sleep Quality: Evidence from Reliability and Validity in Chinese Professional Athletes

Purpose

This study aimed to assess the structural validity of the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) among Chinese professional athletes and examine its test-retest reliability and convergent validity across different timeframes.

Methods

581 Chinese professional athletes participated. Exploratory and confirmatory factor analyses were conducted on the Chinese version of the PSQI. Test-retest reliability was assessed over 2 weeks, 1 week, and 2-3 days within a 1-month timeframe. Additional reliability analysis over a 2-day interval was conducted within a 1-week timeframe. Convergent validity was assessed using Chinese versions of the Insomnia Severity Index (ISI), the Athlete Sleep Screening Questionnaire (ASSQ), and actigraphy. A 1-month tracking was conducted, with weekly completion of the PSQI using a one-week timeframe, supplemented by assessments in the second and fourth week using two-week and one-month timeframes. Relationships between weekly results and those over two weeks and one month examined, along with convergent validity, using sleep diary and actigraphy.

Results

The PSQI exhibited a two-factor structure (sleep quality and sleep efficiency), with good model fit (CFI = 0.960, AGFI = 0.924, TLI = 0.925, RMSEA = 0.085). Test-retest reliability was satisfactory for intervals of one week or more (r = 0.721 ~ 0.753). Using a one-week timeframe, the total score and two dimensions exhibited good reliability (r = 0.769 ~ 0.881), but only the total score and sleep quality showed high correlations with ISI and ASSQ (r = 0.701 ~ 0.839). Throughout the tracking, monthly responses correlated well with the most recent weeks (r = 0.732 ~ 0.866).

Conclusion

The PSQI demonstrates a two-factor structure in Chinese athletes, with sleep quality being predominant. Test-retest reliability within a one-month timeframe is unstable, suggesting a one-week timeframe performs better. Distinguishing between the two dimensions, employing shorter timeframes, and incorporating objective measures are recommended.

Cross-sectional study assessing sleep behavior and musculoskeletal symptoms in elite junior badminton athletes

Sleep inadequacy has previously been associated with increased risk of injury and reduced performance. It is unclear if sleep disorders are associated with musculoskeletal symptoms, which may be a predictor of serious injury and affect performance. The aim was therefore to assess sleep behavior in elite junior badminton players and its association to musculoskeletal symptoms. In 2018, players at the World Junior Badminton Championship completed the Athlete Sleep Behavior Questionnaire and a modified version of the World Olympic Association Musculoskeletal Health Questionnaire. Participants were categorized with poor or moderate/good sleep behavior as the independent variable. Musculoskeletal symptoms were the primary outcome and was categorized using yes/no questions. Relevant musculoskeletal symptoms were defined as pain higher than 30 mm Numeric Rating Scale pain score or more than 30 minutes of joint stiffness a day. Group comparison was performed using chi-square analysis and logistic regression for primary outcome adjusted for age, sex, ethnicity, previous injury, training load, and resting days. Of the 153 participants, 28% reported poor sleep scores. There was no difference between poor and moderate/good sleep score concerning demographic variables such as sex, age, ethnicity, previous injury, training load, and resting days. There were 27% with current musculoskeletal symptoms but with no difference in groups between poor and moderate/good sleep score (P = .376). This yielded an adjusted odds ratio of 1.23 (95% confidence intervals 0.52; 2.90). Twenty-eight percent of the participants reported poor sleep behavior. Twenty-seven percent experienced current musculoskeletal symptoms. We found no statistical differences in reported musculoskeletal symptoms when comparing athletes with poor sleep behavior to athletes with moderate/good sleep behavior.

Effect of Training Load Intensification on the Sleep Pattern of Young Soccer Players

Purpose: The aim of this study was to examine how intensifying training loads over a week affects the sleep patterns of young soccer players on the nights immediately following the intensified training sessions. Methods: Quasi-experimental study. Fifteen young athletes participants of a team engaged in national level competition, underwent two weeks of training with varying load magnitudes-Week 1: low accumulated training load and Week 2: intensified training loads [40% increase in external training load(ETL)]. To characterize the intensification of the workload, the methods PlayerLoad and RPE-Session were employed to measure ETL and internal training load(ITL), respectively. Total sleep time(TST), total time in bed(TTB), sleep efficiency(SE), sleep latency(SL), and wake after sleep onset(WASO) were obtained using actigraphy and daily sleep log. The variables were compared among the days of week (e.g. Monday of week 1 with Monday of week 2, and so forth). Results: Acute training intensification in week 2 led to significant increases in ETL and ITL on Monday and on Wednesday(p < .05), and ETL(p < .05) on Friday on the second week. Improvements in sleep were observed (Tuesday-TST:+80 min, WASO:-29.3 min, SL:-8 min, SE:+9%; Thursday-TST:+86 min, SL:-4 min, SE:+4%; Saturday-TST:+40 min, SL:+1 min) compared to the same day of the previous week. Correlations between ETL and ITL(r = 0.637), ITL and TST(r = 0.572), ITL and SE(r = 0.548) were found. Conclusion: Intensification of training loads results in alterations in sleep variables, notably an elevated TST and SE in the days subsequent to the acute load increment.

Adapting the athlete sleep behavior questionnaire (ASBQ) for Arabic-speaking populations: Translation, reliability testing, and validation using classical theory and item response theory

Sleep is essential for athletes' physical performance as well as their general health, well-being, and quality of life. To assess athletes' sleep behaviors, the Athlete Sleep Behavior Questionnaire (ASBQ) was developed in the English language. However, a validated Arabic-version of the ASBQ is lacking. This study aimed to translate the ASBQ into Arabic (ASBQ-AR) and evaluate its reliability and validity among Arabic-speaking athletes. A total of 458 participants (254 athletes, 202 non-athletes) from four Arabic countries completed the ASBQ-AR and the Insomnia Severity Index (ISI) questionnaires. The psychometric properties of the ASBQ-AR were examined using unidimensional reliability analysis, confirmatory factor analysis (CFA), Item Response Theory (IRT), and convergent validity. The ASBQ-AR had acceptable internal consistency (Cronbach's α = 0.723, McDonald's ω = 0.725) and a factorial structure, confirming its construct validity. CFA demonstrated improved model fit indices after the removal of two potentially misfitting items (items 4 and 13); however, the model's fit to the data remains suboptimal. IRT results indicated that the majority of items demonstrated a good model fit, suggesting effective measurement of the intended construct without significant interference, except for ASBQ-AR 4. Additionally, ASBQ-AR 4 appears to present the highest level of difficulty for respondents. In terms of convergent validity, the mean ASBQ-AR global score was correlated with the mean ISI global score (r = 0.5, p < 0.0001). The ASBQ-AR is a reliable and valid tool for assessing maladaptive sleep practices among Arabic-speaking athletes. Additional refinements to the ASBQ-AR are warranted to optimize its psychometric properties.

Habitual Nocturnal Sleep, Napping Behavior, and Recovery Following Training and Competition in Elite Water Polo: Sex-Related Effects

PURPOSE

To examine nocturnal sleep patterns, napping behaviors, and subjective wellness responses of elite water polo players within an in-season week and to identify whether sleeping patterns differ between men and women.

METHODS

Sleep characteristics of 10 male and 17 female professional water polo players were objectively assessed during 1 week of the in-season period, including 5 training days, 1 match day, and 1 day of rest. Internal load (rating of perceived exertion × duration of training or match) was assessed 30 minutes posttraining or postmatch, and the total quality of recovery was recorded every morning. A series of multilevel models were used to analyze the data.

RESULTS

Time in bed and wake-up time were earlier on both training (P < .001) and rest days (P < .001) than on the day of the match. Internal workload did not predict any of the players' sleeping patterns. Midday naps predicted less time in bed (P = .03) and likely less sleep time (P = .08). The total quality of recovery was predicted only by the total sleep time (P < .01). Women exhibited higher sleep efficiency (P < .001), less waking after sleep onset (P = .01), and a lower number of awakenings (P = .02) than men.

CONCLUSIONS

The current results indicate that the nocturnal sleep patterns of elite water polo players are not associated with internal load and that women display better nocturnal sleep quality compared with men. As long naps interfere with nocturnal sleep, and total nocturnal sleep time predicts total quality of recovery, we suggest that athletes follow hygiene sleep strategies to facilitate adequate nocturnal sleep and next-day recovery.

The interactive effect of sustained sleep restriction and resistance exercise on skeletal muscle transcriptomics in young females

Both sleep loss and exercise regulate gene expression in skeletal muscle, yet little is known about how the interaction of these stressors affects the transcriptome. The aim of this study was to investigate the effect of nine nights of sleep restriction (SR), with repeated resistance exercise (REx) sessions, on the skeletal muscle transcriptome of young, trained females. Ten healthy females aged 18-35 yr old undertook a randomized cross-over study of nine nights of SR (5 h time in bed) and normal sleep (NS; ≥7 h time in bed) with a minimum 6-wk washout. Participants completed four REx sessions per condition (days 3, 5, 7, and 9). Muscle biopsies were collected both pre- and post-REx on days 3 and 9. Gene and protein expression were assessed by RNA sequencing and Western blot, respectively. Three or nine nights of SR had no effect on the muscle transcriptome independently of exercise. However, close to 3,000 transcripts were differentially regulated (false discovery rate < 0.05) 48 h after the completion of three resistance exercise sessions in both NS and SR conditions. Only 39% of downregulated genes and 18% of upregulated genes were common between both conditions, indicating a moderating effect of SR on the response to exercise. SR and REx interacted to alter the enrichment of skeletal muscle transcriptomic pathways in young, resistance-trained females. Performing exercise when sleep restricted may not provide the same adaptive response for individuals as if they were fully rested.NEW & NOTEWORTHY This study investigated the effect of nine nights of sleep restriction, with repeated resistance exercise sessions, on the skeletal muscle transcriptome of young, trained females. Sleep restriction and resistance exercise interacted to alter the enrichment of skeletal muscle transcriptomic pathways in young, resistance-trained females. Performing exercise when sleep restricted may not provide the same adaptive response for individuals as if they were fully rested.

Sleep Difficulties in Swiss Elite Athletes

For athletes, sleep is essential for recovery and performance. Yet, up to two-thirds of athletes report poor sleep quality. Comprehensive data across all sports disciplines on the underlying causes of sleep problems are missing. We reanalyzed a data set of N = 1004 Swiss top athletes across an extensive array of 88 sports to gain knowledge on the specific deficits in sleep health with respect to gender, sport classes, sport-related factors, and well-being. We found that 18% of athletes were affected by at least two out of five high-risk sleep factors: 9% of athletes slept less than 6 h per day, 30% were dissatisfied with their sleep, 17% showed problems falling asleep within 30 min, 18% of athletes reported difficulty maintaining sleep more than three times a week, and 6% of athletes used sleeping pills more than once a week. We found sleep health strongly linked to overall well-being and mental health (22% showed at least moderate symptoms of either depression or anxiety). Therefore, screening and treating sleep disorders might effectively improve mental health and general well-being as well as performance among athletes around the globe.

The Impact of the COVID-19 Pandemic on Elite Swimmers and Water Polo Players: Lessons for the Future

BACKGROUND

The COVID-19 pandemic has disrupted global daily life, including the world of elite athletes. This paper examines the multifaceted impact the COVID-19 pandemic had on elite swimmers and water polo athletes, specifically their mental health, their concerns over the virus, their intentions of getting vaccinated, and sleep disturbances that they may have faced.

METHODS

We conducted a cross-sectional study on elite swimmers and water polo players, using an anonymous questionnaire.

RESULTS

A total of 200 elite athletes participated. The majority of the participants reported a negative impact on their mental health, screened positive for insomnia (n = 107 (53.5%), with females (n = 101; 57.7%), swimmers (n = 100, 66.7%), and university students (n = 71, 71.7%) being more vulnerable (p < 0.001). Concerns about contracting the disease especially during important training or tournament periods and potential career disruption also affected their psychological well-being. While the majority (75%) had the intention of getting vaccinated, an alarming percentage was yet uncertain over its decision.

CONCLUSIONS

This study highlights the significant psychological distress faced by elite aquatic athletes during the pandemic. It emphasizes the difficulties faced by elite swimmers and water polo athletes and determines not only the importance of addressing the vaccination intentions of athletes, but also how critical it is to confront the challenges they face both for their personal health and for the restoration of world sports to their pre-pandemic state. More large-scale studies are required to inform policies targeted at minimizing disruption to the athletes' career, provision of information on preventive measures and vaccination, and improvement in psychological well-being in case of similar major public health issues in the future. Additionally, this study calls for further research to explore the unique challenges faced by aquatic athletes, such as those related to their training environments and fear of contagion, to better support them in future public health crises.

The impact of intermittent fasting during Ramadan on psychomotor and cognitive skills in adolescent athletes

Introduction

Intermittent fasting (IF) represents a dietary intervention similar to caloric restriction, characterized by the strategic limitation of food consumption. Among the diverse array of practices for IF, Ramadan IF (RIF), a religious observance in Islam, mandates that healthy adult Muslims abstain from both food and drinks during daylight hours. In sports, researchers have extensively studied IF effects on health, including sleep and physical performance, but its impact on cognitive functions during RIF remains understudied. Therefore, this study was conducted to evaluate the influence of RIF on psychomotor and cognitive performance among young female athletes.

Methods

To achieve this purpose, a cohort of 23 female handball players, aged 17.2 ± 0.5 years, participated in a series of six testing sessions: one conducted prior to Ramadan (R0), and others during the first (R1), second (R2), third (R3), and fourth (R4) weeks of Ramadan, followed by a session in the week after Ramadan (R5). Each session involved assessments using a Simple Reaction Time Test (SRT), Choice Reaction Time Test (CRT), Vigilance Test (VT), and Mental Rotation Test (MRT). Additionally, dietary intake, body composition, and Pittsburgh Sleep Quality Index (PSQI) scores were evaluated during these periods.

Results and discussion

The obtained data illustrated that there was a decrease in SRT, CRT, VT, and MRT performances during R1 in comparison to R0 (all p < .001). This reduction was also observed in R2, R3, R4, and R5. Notably, during the fourth week of Ramadan (R4), these cognitive and psychomotor parameters were significantly lower than during the earlier weeks (R1, R2, R3; all p < .001). Furthermore, a gradual decrease in total PSQI scores, sleep quality, and sleep duration was observed throughout the Ramadan period, reaching the lowest levels during R4. These findings illustrate that RIF has a significantly detrimental impact on neuromuscular and cognitive abilities as well as sleep quality in young female athletes. The study also highlights a fluctuating pattern in cognitive function across the four weeks of Ramadan, with the most pronounced decline observed during the final week of fasting illustrating the importance of conducting similar studies on normal individuals from both genders with larger sample size.

Effect of Foam Roll recovery method on performance in water polo players: a randomized controlled trial

OBJECTIVES

This intervention study aimed to evaluate how the use of Foam Roller (FR) as a recovery strategy affects water polo performance after a seven-week (28-session) program.

DESIGN

A randomized controlled trial.

METHODS

Thirty water polo players (14 male amateur players and 16 female sub-elite players) were assigned by means of sealed opaque envelopes to the control group (CG) or Foam Roller Group (FRG) and performed the same total number and intensity of training sessions. Test protocols were performed before (pretest), in-test (week 5), and after the intervention period (posttest). These included water polo-specific performance tests such as in-water boost, throwing speed, and 20 m sprint swimming tests. In addition, during the intervention, heart rate (HR), the scale of perceived exertion of the session (sRPE), and total quality recovery scale (TQR) data were recorded.

RESULTS

There were no differences in the baseline values in any of the variables analyzed between CG and FRG. A small decrease in in-water boost was observed in CG (-2%, ES = -0.35 [-0.95: 0.26], p = 0.016, very likely small) and in FRG (-2%, ES = -0.33 [-0.93: 0.27], p = 0.021, likely small). No significant changes were found in either the 20 m swim test or the throwing test in CG and FRG. No clear differences among groups and weeks were found in sRPE, TQR and HR.

CONCLUSION

The findings indicate that the use of FR as a recovery tool after training and matches is not useful in water polo players.

Sink or Swim? Sleep Patterns in Highly Trained Adolescent Swimmers during the In-Season Phase of Training

Objectives  The aim of this study was to investigate the sleeping patterns of highly-trained adolescent swimmers. Further objectives were to compare subjective and objective measures of sleep and to evaluate the relationship between electronic device use and sleep in this cohort. Methods  Fifteen national-level swimmers (age: 16.4 ± 1.0 years) wore wrist actigraphs while completing sleep diaries over a two-week training period. Types of nights were classified as early morning training (≤7am - EARLY), day training (>7am - DAY), and no training (REST). Information on electronic device use before bed and other sleep behaviors was collected via questionnaires. Results  Total sleep time (TST) was significantly ( p  < 0.05) shorter on nights preceding EARLY (5:53 ± 1:06 hour:min) compared with nights preceding DAY (7:40 ± 1:12 hour:min) and REST (7:59 ± 1:19 hour:min). Participants overestimated subjective TST by ∼54 minutes when compared with objectively measured TST ( p  < 0.05). Discussion  Adolescent athletes obtained a greater amount of sleep prior to later training the next day or before rest days, when compared with early morning swim training the next day. Adolescents also overestimated their sleep duration by ∼1 hour per night. There were no significant relationships between electronic device use at night and measured sleep indices.

Does overreaching from endurance-based training impair sleep: A systematic review and meta-analysis

BACKGROUND

Overreaching is often linked to a deterioration in sleep quality, yet a comprehensive review is lacking. The aim of this systemic review and meta-analysis was to synthesise the literature and quantify the effect of overreaching from endurance-based training on sleep quality.

METHOD

The review was conducted following the PRISMA guidelines. The final search was conducted in May 2023 using four electronic databases (Web of Science Core Collection, MEDLINE, Cochrane Central Database, SPORTDiscus). Studies were included for a qualitative review, while random-effects meta-analyses were conducted for objective and subjective sleep.

RESULTS AND DISCUSSION

The search returned 805 articles. Fourteen studies were included in the systematic review; Three and eight articles were eligible for the meta-analyses (objective and subjective, respectively). On average, the overreaching protocols were sixteen days in length (6 to 28 days) and included exercise modalities such as cycling (number of studies [k] = 5), rowing (k = 4), triathlon (k = 3), running (k = 2), and swimming (k = 1). Actigraphy was the only form of objective sleep measurement used across all studies (k = 3), while various instruments were used to capture subjective sleep quality (k = 13). When comparing objective sleep quality following the overreaching intervention to baseline (or a control), there was a significant reduction in sleep efficiency (mean difference = -2.0%; 95% CI -3.2, -0.8%; Glass' Δ = -0.83; p < 0.01). In contrast, when comparing subjective sleep quality following the overreaching intervention to baseline (or a control), there was no effect on subjective sleep quality (Glass' Δ = -0.27; 95% CI -0.79, 0.25; p = 0.08). Importantly, none of the included studies were judged to have a low risk of bias. While acknowledging the need for more high-quality studies, it appears that overreaching from endurance-based training can deteriorate objective sleep without influencing the perception of sleep quality.

PROTOCOL REGISTRATION

This protocol was registered in The International Prospective Register of Systematic Reviews (PROSPERO) on 21st November 2022, with the registration number CRD42022373204.

The Effect of Sleep on the Health and Dietary Behaviours of GAA Athletes

Decreased sleep quality and duration is associated with an array of negative health outcomes. Evidence suggests athletes are susceptible to sleep inadequacies that may in turn affect their health and dietary behaviours. This study aimed to explore the sleep profile of both male and female Gaelic games players, at an elite and sub-elite level and compare how poor sleep relates to subjective health complaints and food cravings. One hundred and seventy Gaelic games players completed the Pittsburgh Sleep Quality Index (PSQI), Subjective Health Complaints Inventory (SHC) and Food Cravings Questionnaire-Trait-Reduced (FCQ-T-r). Participants were categorised into two groups: poor sleepers (PSQI ≥ 5) and good sleepers (PSQI < 5). Outcome measures of health and food cravings were analysed across the groups, Mann-Whitney U tests were used to assess differences, and Spearman's rank-order correlations were used to determine relationships between variables. Sixty-seven % of athletes were categorised as poor sleepers. There were no significant differences in PSQI scores across genders (p = 0.088) or playing level (p = 0.072). Poor sleepers experienced significantly increased SHC (p < 0.001) and female athletes had significantly more SHC compared to males (p < 0.001). Female athletes experienced more food cravings than males (p = 0.013). However, there were no significant differences in food cravings between good and poor sleepers (p = 0.104). The findings suggest a high prevalence of poor sleepers amongst GAA athletes. Furthermore, a significant relationship exists between poor sleep and health complaints with females at a higher risk of worsened health complaints and higher food cravings. Sleep screening and education interventions to enhance sleep in GAA athletes are advocated.

Immediate effects of Ramadan on objective time asleep in male youth football players from the Middle East: an interrupted time-series study

OBJECTIVE

To examine the abrupt effects of Ramadan onset on actigraphy-based time asleep in male youth Muslim football players.

METHODS

We adopted a quasi-experimental, interrupted time-series research design and tracked objective time asleep over a minimum of 12 consecutive nights in the two weeks prior to and immediately after Ramadan onset, respectively. Twenty-two, male academy student-athletes (chronological age range: 12.6 to 16.2 years) participated in the study (464 individual observations). Segmented generalized mixed-effects modelling estimated the effects of Ramadan onset on time asleep during the first period of night sleep only.

RESULTS

Ramadan onset led to an immediate mean reduction of 89 min (95% confidence interval [CI], 54 to 123 min) in time asleep during the first period of night sleep compared to pre-Ramadan sleep patterns. Model-adjusted estimated marginal means for time asleep were ~ 5.7 h (95%CI, 5.1 to 6.2 h) before and ~ 4.2 h (95%CI, 3.6 to 4.7 h) after Ramadan onset. Night sleep interruptions resulting in two or more fragmented periods accounted for 8% (95%CI, 2 to 21%) to 19% (95%, 11 to 29%) of sleep observations before and after Ramadan onset, respectively.

CONCLUSIONS

The onset of Ramadan determined an abrupt reduction in time asleep of ~ 1 h 30 min in the first period of a night cycle and contributed to additional problems of heterogeneous sleep fragmentation that can impact optimal school learning and youth athlete performance development processes.

Night-to-night variability of objective sleep outcomes in youth Middle Eastern football players

OBJECTIVE

To describe components of night-to-night variation in objective measures of sleep.

METHODS

We conducted a secondary data analysis of consecutive and chronologically ordered actigraphy-based measurements for time in bed (min), time asleep (min), and wake-after-sleep onset (min). This investigation examined 575 individual night-based measures available for a sub-sample of fifty-two, male youth Middle Eastern football players tracked over a 14-day surveillance period (chronological age range: 12.1 to 16 years). Distinct multivariable-adjusted generalized additive models included each objective sleep outcome measure as dependent variable and disaggregated components of variation for night measurement-by-sleep period interaction, week part (weekday or weekend), and study participant random effects from within-subject night-to-night sleep variation.

RESULTS

The within-subject standard deviation (SD) of ±98 min (95% confidence interval [CI], 92 to 104 min) for time in bed, ±87 min (95%CI, 82 to 93 min) for time asleep, and ±23 min (95%CI, 22 to 25 min) for wake-after-sleep-onset overwhelmed other sources of variability and accounted for ∼44% to 53% of the overall night-to-night variation. The night measurement-by-fragmented sleep period interaction SD was ±83 min (95%CI, 44 to 156 min) for time in bed, ±67 min (95%CI, 34 to 131 min) for time asleep, and ±15 min (95%CI, 7 to 32 min) for wake-after-sleep-onset that accounted for ∼22% to 32% of each sleep outcome measure overall variability.

CONCLUSIONS

Substantial random night-to-night within-subject variability poses additional challenges for strategies aiming to mitigate problems of insufficient and inconsistent sleep that are detrimental to school learning and youth athlete development processes.

Sleep duration is associated with overnight changes in perceived fatigue in elite women soccer players

The current study aimed to describe sleep habits and analyze the associations between sleep indices, changes in perceived fatigue (Δ Fatigue) and external training load measures in women soccer players during a 7-day training camp. Sixteen elite women soccer players (age: 25.4 ± 3.6 years; mean ± SD) from the Portuguese Women's National Team participated in the study. Sleep indices (sleep duration and efficiency) were measured using a wrist-worn accelerometer. External training loads measures were measured using GPS devices. Players also reported perceived fatigue using a Likert scale (1 - very, very low to 7 - very, very high) before and immediately after sleep. Players' within-subject coefficient of variation for sleep duration was 5.6%, and 4.6% for sleep efficiency. Individually, 8 players (50%) slept less than 7 h per night throughout the training camp, and the same number of athletes had a sleep efficiency lower than 85%. Similar values (p<0.05) were measured for sleep duration and efficiency between training and match days. A moderate negative within-subjects correlation was found between Δ Fatigue and sleep duration (adjusted for pre-sleep fatigue) [r = -0.32; 95% Confidence Interval (-0.51 - -0.08); p = 0.04]. These findings reinforce the importance of sleep in the recovery process of elite women soccer players, showing that more sleep may help to attenuate fatigue.

Assessing sleep quality in elite and junior cyclists

In the pursuit of optimal recovery, the significance of sleep cannot be overstated for elite cyclists, including high-level cyclists within the junior category. This study aims to assess the sleep quality of elite athletes of different categories and disciplines, including junior. The sleep quality of 112 high-level cyclists (males n = 80; females n = 32) participating in endurance and sprint disciplines was evaluated using the Pittsburgh Sleep Quality Index (PSQI). A noteworthy 41% of both elite and junior cyclists displayed poor sleep quality. No significant differences were observed between elite and junior cyclists in terms of sleep quality, but there was a medium effect size, indicating greater sleep efficiency in junior cyclists [0.36 (0.16, 0.53)]. Gender differences were found, with females exhibiting worse PSQI scores (males = 4.00 [2.25]; females 5.00 [3.00]; p = 0.035). Endurance cyclists spent more time in bed compared to cyclists from sprinting disciplines (8:30 [1.00] and 8:00 [1:03], respectively; p = 0.019). These findings reveal poor sleep habits, even among individuals classified as good sleepers by the PSQI, emphasizing the importance of preventing sleep disorders in cyclists. This study provides valuable insights into athlete sleep quality, encompassing various categories, genders, and cycling disciplines. In conclusion, elite cyclists demonstrate suboptimal sleep quality, suggesting the potential for interventions utilizing the PSQI. These findings advocate for the incorporation of sleep quality assessments into routine evaluations for athletes.

Interval training has more negative effects on sleep in adolescent speed skaters: a randomized cross controlled trial

Objective

Sleep is an essential component of athletic performance and recovery. This study aimed to investigate the effects of different types of high-intensity exercise on sleep parameters in adolescent speed skaters.

Methods

Eighteen male adolescent speed skaters underwent aerobic capacity testing, Wingate testing, and interval training in a randomized crossover design to assess strength output, heart rate, and blood lactate levels during exercise. Sleep quality after each type of exercise was evaluated using the Firstbeat Bodyguard 3 monitor.

Results

The results showed that Wingate testing and interval training led to decreased sleep duration, increased duration of stress, decreased RMSSD, and increased LF/HF ratio (p < 0.01). Conversely, aerobic capacity testing did not significantly affect sleep (p > 0.05). The impact of interval training on sleep parameters was more significant compared to aerobic capacity testing (p < 0.01) and Wingate testing (p < 0.01).

Conclusion

High-intensity anaerobic exercise has a profound impact on athletes' sleep, primarily resulting in decreased sleep duration, increased stress duration, decreased RMSSD, and increased LF/HF ratio.

The Night-Time Sleep and Autonomic Activity of Male and Female Professional Road Cyclists Competing in the Tour de France and Tour de France Femmes

BACKGROUND

Sleep is a critical component of recovery, but it can be disrupted following prolonged endurance exercise. The objective of this study was to examine the capacity of male and female professional cyclists to recover between daily race stages while competing in the 2022 Tour de France and the 2022 Tour de France Femmes, respectively. The 17 participating cyclists (8 males from a single team and 9 females from two teams) wore a fitness tracker (WHOOP 4.0) to capture recovery metrics related to night-time sleep and autonomic activity for the entirety of the events and for 7 days of baseline before the events. The primary analyses tested for a main effect of 'stage classification'-i.e., rest, flat, hilly, mountain or time trial for males and flat, hilly or mountain for females-on the various recovery metrics.

RESULTS

During baseline, total sleep time was 7.2 ± 0.3 h for male cyclists (mean ± 95% confidence interval) and 7.7 ± 0.3 h for female cyclists, sleep efficiency was 87.0 ± 4.4% for males and 88.8 ± 2.6% for females, resting HR was 41.8 ± 4.5 beats·min-1 for males and 45.8 ± 4.9 beats·min-1 for females, and heart rate variability during sleep was 108.5 ± 17.0 ms for males and 119.8 ± 26.4 ms for females. During their respective events, total sleep time was 7.2 ± 0.1 h for males and 7.5 ± 0.3 h for females, sleep efficiency was 86.4 ± 1.2% for males and 89.6 ± 1.2% for females, resting HR was 44.5 ± 1.2 beats·min-1 for males and 50.2 ± 2.0 beats·min-1 for females, and heart rate variability during sleep was 99.1 ± 4.2 ms for males and 114.3 ± 11.2 ms for females. For male cyclists, there was a main effect of 'stage classification' on recovery, such that heart rate variability during sleep was lowest after mountain stages. For female cyclists, there was a main effect of 'stage classification' on recovery, such that the percentage of light sleep (i.e., lower-quality sleep) was highest after mountain stages.

CONCLUSIONS

Some aspects of recovery were compromised after the most demanding days of racing, i.e., mountain stages. Overall however, the cyclists obtained a reasonable amount of good-quality sleep while competing in these physiologically demanding endurance events. This study demonstrates that it is now feasible to assess recovery in professional athletes during multiple-day endurance events using validated fitness trackers.