Impaired Sleep Mediates the Negative Effects of Training Load on Subjective Well-Being in Female Youth Athletes

Menstrual Cycle and Situational Match Variables: Effects on Well-Being in Professional Female Soccer Players

Purpose: We examined whether the situational match factors (location, result, and opposition quality), as well as playing position and menstrual cycle phase, influenced self-reported well-being in female soccer players. Methods: Twenty-two professional players (25 ± 5 years) from a squad in the Women's Super League in England self-reported their menstrual cycle phase via an online survey, and their soreness, sleep, stress, mood, and fatigue on a 1 (positive) to 5 (negative) scale on the morning of match day (MD) and for the next 3 days (referred to as MD + 1, MD + 2, MD + 3, respectively). Data was collected for 26 matches across the 2021-2022 season. Session rate of perceived exertion (sRPE) and total distance covered (measured with GPS) were measured on match and training days. Results: Menstrual cycle phase and the situational match factors had no influence on distance covered during matches and sRPE (p > .05). Sleep was worse on MD + 1 (p < .001; g = 1.59) and MD + 2 (p = .005; g = 0.98) after away matches. Stress and mood were > 28% worse after playing top vs. mid and bottom table opposition at MD + 1, and significantly worse when losing compared to winning and drawing (p > .05). Playing position and menstrual cycle phase has no influence on self-reported well-being (p > .05). Conclusion: Sleep quality was worse after away matches and losing matches negatively affects stress and mood for 2 days post-match, but menstrual cycle phase does not influence post-match well-being.

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.

Relationship between Workload, Psychological State and Recovery in Female Soccer Athletes

This study assessed the multifaceted relations between measures of workload, psychological state, and recovery throughout an entire soccer season in female collegiate soccer athletes (19.8±1.2 yrs, 132±12.3 lbs, 63±3.2 in). A prospective longitudinal study was utilized to measure workload (GPS training load, Rate of Perceived Exertion (RPE), psychological state (mental stress, mental fatigue, and mood), and recovery (sleep duration, sleep quality, and soreness), during 90 observations (59 training sessions and 21 games). Separate linear-mixed effect models were used to assess outcomes of RPE, soreness, and sleep duration. A linear mixed-effects model explained 59% of the variance in RPE following each session. Specifically, each standard deviation increase in GPS load and mental stress in the morning prior to training increased RPE by 1.46 (SE=0.08) and 0.29 (SE=0.07), respectively, following that day's training. Furthermore, a significant interaction was found between several predictor variables and chronological day in the season while predicting RPE. Specifically, for each standard deviation increase in GPS load, RPE went up by 0.0055 per day during the season suggesting that load had a higher impact on RPE as the season progressed. In contrast, the interaction of day by mental stress, sleep duration, and soreness continued to be stronger as the season progressed. Each linear mixed-effect model predicted a larger amount of variance when accounting for individual variations in the random effects.

The Influence of Emergency Call Volume on Occupational Workload and Sleep Quality in Urban Firefighters

OBJECTIVE

The aim of the study is to determine the impact of emergency call volume on exertion, autonomic activity, and sleep among urban structural firefighters.

METHODS

Thirty-four firefighters wore a wrist-based monitor to track sleep and autonomic parameters and rated their level of perceived exertion (Borg Rating of Perceived Exertion) and subjective sleepiness after a 24-hour shift. Predictive variables included total run time and total run time after 11:59 PM.

RESULTS

Total run time and sleep duration accounted for Borg Rating of Perceived Exertion and subjective sleepiness, while total run time and total run time after 11:59 PM accounted for sleep durations on-duty.

CONCLUSIONS

The current results suggest that emergency call volume is associated with indicators of exertion and sleep. As such, call volume tracking is an important consideration for departments to ensure personnel readiness and wellness and provide a method of tracking the occupational demands experienced by firefighters on-duty.

The effects of mobile phone dependence on athletic performance and its mechanisms

Mobile phone dependence (also known as internet dependence, MPD), defined as a problematic behavior characterized by excessive use or intermittent craving to use a mobile phone, results in various social, behavioral, and affective problems in daily life. In sports, MPD is directly related to the physical and mental health and sports performance of athletes. The individual and environmental factors, neurobiological mechanisms and theoretical models of MPD affecting athletic performance were analyzed by reviewing previous studies, aiming to construct effective training and development protocols to prevent and control the occurrence of MPD in athletes. At present, athletic performance can be affected by MPD through individual factors and environmental factors. The neurobiological mechanisms between the two are based on the brain reward system and microwave radiation from mobile phones, with athletic performance being restricted by alterations in the corresponding brain regions. Relevant theoretical models mainly include the social cognitive model of self-regulation and the integrative model of self-control, which explain the interrelationship between MPD and athletic performance from the perspectives of athletes' self-regulation and self-control, respectively. As an emerging phenomenon, the influence pathways and mechanisms by which MPD affects athletic performance need to be further investigated. A longitudinal perspective should be adopted to trace the dynamic impact relationship between the two, and developing relevant theoretical frameworks from an interdisciplinary research perspective should be valuable for providing theoretical support for coaches and sports administrators to formulate scientific training protocols and thus improve the mental health of athletes.

The Associations Between Wellbeing and Injury Differ by Time Loss in Collegiate Athletes

BACKGROUND

Self-reported wellbeing measures such as mood and soreness have been identified as predictors of injury risk. However, most research has focused on investigating time-loss injuries even though nontime-loss injuries are more prevalent.

HYPOTHESIS

Impairments in sleep and subjective wellbeing would be associated with increased injury for both time-loss and nontime-loss injuries.

STUDY DESIGN

Prospective longitudinal study.

LEVEL OF EVIDENCE

Level 3.

METHODS

During 2022, 127 athletes completed a daily survey that inquired about training load and sleep from the previous day along with mood, stress, and soreness on the current day. Incidence of injury was also monitored using documentation provided by athletes' respective athletic trainers. Mixed effect models were used to analyze the relationship between wellbeing and sleep measures with injury.

RESULTS

Self-reported wellbeing, based most closely on soreness the day of injury, by National Collegiate Athletic Association Division 1 collegiate athletes was predictive of time-loss injuries, whereas no significant relationship was identified for nontime-loss injuries. Specifically, 1 unit increase in soreness was associated with a 39% increase in odds of sustaining a time-loss injury.

CONCLUSION

This study found that subjective wellbeing and sleep have a different relationship with injury dependent upon whether the resulting injury leads to time loss.

CLINICAL RELEVANCE

Self-reported wellbeing appears to be a relevant predictor of injury among collegiate athletes for time-loss injuries.

Training Load and Current Soreness Predict Future Delayed Onset Muscle Soreness in Collegiate Female Soccer Athletes

Background

Delayed onset muscles soreness (DOMS) is an indication of muscle stress and trauma that develops from excessive musculoskeletal loads. Musculoskeletal loads can be measured with wearable devices, but there is limited research on specific training load metrics that most correlate with DOMS after activity.

Purpose

To determine the predictive capabilities of training load variables on the development of lower extremity DOMS in female collegiate soccer athletes throughout an entire season.

Study Design

Prospective Cohort.

Methods

Twenty-seven collegiate female soccer athletes reported their lower extremity DOMS each day prior to all soccer activity. Participants wore Polar heart rate and global positioning monitors to capture training load measures. Pearson correlation coefficients were used to assess the relationships between the training load variables and change in DOMS when collapsed across dates. Separate linear mixed models were performed with the following day's DOMS as the outcome variable, training load and the current day's DOMS as predictor variables, and participants serving as random intercepts.

Results

All training load variables significantly predicted change in DOMS, with number of decelerations (ρ=0.72, p <0.001), minutes spent at greater than 80% of maximum heart rate (HRmax) (ρ=0.71 , p <0.001), and distance (ρ=0.70 , p <0.001) best correlating with change in DOMS. Linear mixed models revealed a significant interaction of all training load and current day's DOMS on the following day's DOMS (p<0.001), but number of decelerations, HRmax, and total number of accelerations demonstrated the highest coefficient of determination (R2 marginal=33.2% - 29.2% , R2 conditional= 46.9% - 44.8%).

Conclusions

Training load variables paired with the current day's DOMS significantly predict lower extremity DOMS in the future, with number of decelerations, accelerations, and HRmax best predicting future DOMS. Although this demonstrates that training load variables predict lower extremity DOMS, future research should incorporate objective measures of strength or jump kinetics to identify if similar relationships exist.

Level of Evidence

Level 3.

Waking Up to the Issue! Research Inattention and Sex-Related Differences Warrant More Sleep Studies in Female Athletes

Understanding sleep patterns and behaviors of athletes is essential for developing targeted sleep-based interventions for implementation in practice. However, more than double the number of sleep studies have examined male athletes compared with female athletes, making the current understanding of sleep patterns, behaviors, and interventions among athletes disproportionately indicative of men. Consequently, this review demonstrates the need for more female-specific sleep data among athlete populations due to research inattention and sex-related differences. Specifically, this review identifies variations in sleep patterns and behaviors between male and female athletes, as well as physiological and lifestyle factors that potentially affect sleep patterns and behaviors across the lifespan, specifically in female athletes. In this regard, evidence suggests some female athletes experience longer sleep durations and better objective sleep quality, but similar or worse subjective sleep quality compared with male athletes. Additionally, scheduling training in the morning or throughout the day may benefit sleep in some female athletes. Considering sleep disorders, women may be at greater risk for insomnia and restless legs syndrome compared with men, which may be attributed to pregnancy, as well as a higher prevalence of anxiety and depressive symptoms, iron deficiency without anemia, and use of psychotropic medication among women. Finally, the menstrual cycle, menstrual disorders, oral contraceptive use, and the postpartum period have been shown to exert detrimental effects on sleep patterns and behaviors and should theoretically be considered when monitoring and managing sleep in female athletes.

Young para-athletes display more hedonic well-being than people with disabilities not taking part in competitive sports: insights from a multi-country survey

Hedonic well-being relates to how individuals experience and rate their lives. People with disabilities due to their pathology may more frequently suffer from anxiety and depressive disorders than their able-bodied counterparts. Sports participation is an essential way to cope with disability. On the other hand, compared with their able-bodied peers, para-athletes undergo a unique series of stressors. Little is known in terms of hedonic well-being in this specific population. We present the results of a multi-country survey of self-perceived hedonic well-being by para-athletes of different sports disciplines and a control group (disabled individuals not playing competitive sports), using the "Psychological General Well-Being Index" (PGWBI). We included 1,208 participants, aged 17.39 years, 58.4% male, 41.6% female, and 70.3% para-athletes. Para-athletes exhibited higher well-being than disabled people, for all domains of the PGWBI scale. The nature of disability/impairment was significant, with those with acquired disability reporting lower well-being. Those taking part in wheelchair basketball, para-athletics, and para-swimming competitions had a higher likelihood of reporting well-being, whereas those engaged in wheelchair rugby exhibited lower well-being compared with controls. This large-scale investigation can enable a better understanding of the self-perceived hedonic well-being of disabled people.

Well-being and quality of life in people with disabilities practicing sports, athletes with disabilities, and para-athletes: Insights from a critical review of the literature

Global well-being (GWB) is a complex, multi-dimensional, and multi-faceted construct that can be explored from two different, but often overlapping, complementary perspectives: the subjective and the objective ones. The subjective perspective, in turn, is comprised of two dimensions: namely, the hedonic and the eudaimonic standpoints. Within the former dimension, researchers have developed the concept of subjective hedonic well-being (SHWB), whereas, within the latter, they have built the framework of psychological and social well-being (PSWB). Disabled people have poorer well-being due to their pathology and may more frequently suffer from anxiety and depressive disorders than their able-bodied counterparts. Sports participation is an essential way to cope with disability. On the other hand, compared with their able-bodied peers, athletes with disabilities and para-athletes undergo a unique series of stressors. Little is known in terms of hedonic and eudaimonic well-being and quality of life in this specific population. Here, we review the literature, with an emphasis on the current state-of-art and gaps in knowledge that need to be addressed by future research. High-quality, large-scale investigations are needed to have a better understanding of the self-perceived (hedonic) and objective (eudaimonic) well-being and quality of life of disabled people practicing sports, athletes with disabilities, and para-athletes.

The Influence of Different Training Load Magnitudes on Sleep Pattern, Perceived Recovery, and Stress Tolerance in Young Soccer Players

ABSTRACT

Ferreira, ABdM, Ribeiro, BLL, Batista, EdS, Dantas, MP, and Mortatti, AL. The influence of different training load magnitudes on sleep pattern, perceived recovery, and stress tolerance in young soccer players. J Strength Cond Res 37(2): 351-357, 2023-The aim of this study was to analyze the influence of 3 weeks on sleep parameters, perceived recovery, and stress tolerance in young soccer players using different training load magnitudes. A total of 13 young male soccer athletes (15.9 ± 0.5 years; 68.7 ± 6.1 kg; 170 ± 7 cm) who performed 3 typical training weeks with different workloads were analyzed. The external training load (ETL) was verified by the PlayerLoad method, and the internal training load (ITL) was determined using the session rating of perceived exertion method. Sleep was monitored using a wrist-actigraphy monitor. Sleep variables, including total time in bed (TTB), total sleep time (TST), sleep latency (SL), wake after sleep onset (WASO), and sleep efficiency (SE), were evaluated across all nights of sleep. The recovery status was assessed with the perceived recovery status (PRS) scale, and the stress tolerance was monitored using the "daily analysis of life demands of athletes" questionnaire. There was an increase in sleep time during the week with the highest training load (week 2) (TTB: +35 minutes, TST: +46 minutes, SL: -5 minutes, SE: +3%). There was no difference in the PRS or in the stress tolerance during the evaluation weeks. A very large within-individual correlation was observed between ITL and ETL ( r = 0.78) and moderate within-individual correlation between ETL and TST ( r = 0.34), between ITL and TST ( r = 0.45), and between ITL and SE ( r = 0.359). These results showed that there was an increase in TST during a microcycle with intensified loads, without impairing bedtime and resulting in maintenance of the perceived recovery or stress tolerance values.

Sport specialization, sleep, fatigue, and psychosocial ratings: do highly specialized athletes differ from their less specialized peers?

OBJECTIVES

To determine if sleep quality, fatigue, anxiety, depressive symptoms, or perceptions of sport participation differ between high-, moderate-, and low-specialized high school athletes with or without prior injuries.

METHODS

During pre-participation physical examinations (PPE), high school athletes completed questionnaires on sport specialization level, history of time-loss orthopedic injury, perceptions of sport participation, as well as sleep quality (Pittsburgh Sleep Quality Index (PSQI)), fatigue, anxiety, and depressive symptoms (Patient-Reported Outcomes Measurement Information System (PROMIS®)). Athletes were grouped according to sport specialization level and history of prior time-loss orthopedic injury.

RESULTS

A total of 186 athletes completed the study: 49% (n = 92; mean age = 15.3 ± 2.0 yrs; 50% female) were low specialized, 34% (n = 64; mean age = 15.3 ± 1.3 yrs; 47% female) were moderately specialized, and 16% (n = 30; mean age = 15.7 ± 1.1 yrs; 57% female) were highly specialized. Groups were similar for demographics, training volume, and injury history. Compared to the moderate-specialization group, highly specialized athletes reported higher levels of fatigue (3.1 ± 3.7 vs. 1.5 ± 2.2; p = 0.02), anxiety (3.6 ± 4.1 vs. 1.8 ± 2.6; p = 0.02), and depressive symptoms (2.4 ± 4.0 vs. 0.8 ± 2.0; p = 0.02). No differences in psychometric ratings, sleep quality, or perceptions of sport participation were observed between the low/moderate- or low/high-specialization groups. We did not observe any significant differences between groups who did and did not report a history of prior time-loss orthopedic injury.

CONCLUSIONS

Highly specialized high school athletes report higher levels of fatigue, more anxiety symptoms, and more depressive symptoms than their moderately specialized peers, despite no differences in training volume or injury history. Low specialized athletes did not differ from moderately specialized or highly specialized athletes in the aforementioned domains, and there were no differences in sleep quality across specialization groups. These findings add to the current body of literature on early sport specialization by illustrating the distinctive psychosocial implications of sport specialization and demonstrating the need for further prospective research.

Sleep and the Young Athlete

CONTEXT

Sleep plays a vital role in cognitive and physical performance. Teenage athletes (ages 13-19 years) are considered especially at risk for disordered sleep and associated negative cognitive, physical, and psychosomatic effects. However, there is a paucity of evidence-based recommendations to promote sleep quality and quantity in athletes who fall within this age range. We performed a review of the literature to reveal evidence-based findings and recommendations to help sports instructors, athletic trainers, physical therapists, physicians, and other team members caring for young athletes provide guidance on sleep optimization for peak sports performance and injury risk reduction.

METHODS

PubMed, Scopus, and Cochrane CENTRAL were searched on May 11, 2016, and then again on September 1, 2020, for relevant articles published to date.

STUDY DESIGN

Narrative review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Few studies exist on the effects disordered sleep may have on teenage athletes. By optimizing sleep patterns in young athletes during training and competitions, physical and mental performance, and overall well-being, may be optimized. Adequate sleep has been shown to improve the performance of athletes, although further studies are needed.

CONCLUSION

Twenty-five percent of total sleep time should be deep sleep, with a recommended sleep time of 8 to 9 hours for most young athletes. Screen and television use during athletes' bedtime should be minimized to improve sleep quality and quantity. For young athletes who travel, jet lag can be minimized by allowing 1 day per time zone crossed for adjustment, limiting caffeine intake, planning meals and onboard sleeping to coincide with destination schedules, timing arrivals in the morning whenever possible, and using noise-canceling headphones and eyeshades.

STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT)

B.

The Relationships Between Sport Specialization, Sleep, and Quality of Life in Female Youth Volleyball Athletes

BACKGROUND

Although sport specialization may be associated with stress and burnout among youth athletes, the relationship with quality of life (QOL) remains unknown. The purpose of this study was to evaluate the relationship between sport specialization, sleep, and QOL in female youth athletes.

HYPOTHESIS

Higher levels of specialization are associated with increased daytime sleepiness and worse QOL.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Female high school volleyball players completed preseason surveys to determine sport specialization (low, moderate, high), injury history, QOL, sleep duration, and daytime sleepiness. QOL and sleep variables were compared across specialization groups. Multivariable linear regression models were developed to evaluate the associations between sleepiness, QOL, specialization, grade in school, and injury history.

RESULTS

Of 1482 participants, 591 (40%), 436 (29%), and 455 (31%) were categorized as low, moderate, and high specialization, respectively. Highly specialized athletes demonstrated worse QOL (median 91.3 [interquartile range 86-96]) than low (92.4 [88-97], P = 0.05) and moderate (93.5 [88-99], P = 0.05) specialization groups and greater daytime sleepiness (11 [7-15]) than low (10 [6-14], P < 0.001) and moderate (10 [6-14], P < 0.001) specialization groups. In the multivariable model, QOL was negatively associated with prior injury occurrence (β = -1.1 ± 0.5, P = 0.02), but not grade in school (β = -0.08 ± 0.2, P = 0.71) or specialization (moderate: β = 0.08 ± 0.5, P = 0.88; high: β = -0.70 ± 0.5, P = 0.18). Daytime sleepiness increased with high specialization (β = 1.12 ± 0.3, P < 0.001) and grade (β = 0.76 ± 0.1, P < 0.001), but not prior injury (β = 0.51 ±0.3, P = 0.10).

CONCLUSION

Highly specialized female volleyball athletes demonstrate decreased QOL, perhaps because of higher rates of prior injury. Specialization is also associated with increased daytime sleepiness.

CLINICAL RELEVANCE

Sport participation patterns and injury may have implications for QOL in youth athletes.

A Systematic Review of the Reporting Quality of Observational Studies That Use Mediation Analyses

Mediation analysis is a common statistical method used to investigate mechanisms of health exposure and interventions. The reporting quality of mediation studies used in randomised controlled trials has been considered heterogeneous and incomplete. The reporting quality of mediation analysis in observational studies is unknown. We conducted a systematic review to describe the reporting standards of recently published observational studies that used mediation analysis to understand the mechanism of health exposures. We searched for studies published between June 2017 and June 2019 indexed in EMBASE, MEDLINE and PsycINFO. Two reviewers screened articles and selected a random sample of 50 eligible studies for inclusion. We included studies across 13 healthcare fields and ten different health conditions. Most studies (74%) collected data on healthy individuals to assess their risk of developing a health disorder. Psychosocial and behavioural factors (self-control, self-esteem, alcohol consumption, pain) were the most prevalent exposures (n = 30, 60%), outcomes (n = 23, 46%) and mediators (n = 29, 58%). Most studies used a cross-sectional design (64%, n = 32), and a few studies reported sample size calculations (4%, n = 8). In 20% (n = 10) of the studies, adjustment for confounders was reported. Only 10% (n = 5) of studies reported the assumptions underlying the mediation analysis, and 14% (n = 7) of studies conducted some sensitivity analysis to assess the degree which unmeasured confounders would affect the estimate of the mediation effect. Mediation analysis is a common method used to investigate mechanisms in prevention research. The reporting of mediation analysis in observational studies is incomplete and may impact reproducibility, evidence synthesis and implementation.

In-Season Internal Load and Wellness Variations in Professional Women Soccer Players: Comparisons between Playing Positions and Status

The internal intensity monitoring in soccer has been used more in recent years in men's football; however, in women's soccer, the existing literature is still scarce. The aims of this study were threefold: (a) to describe the weekly variations of training monotony, training strain and acute: chronic workload ratio through session Rated Perceived Exertion (s-RPE); (b) to describe weekly variations of Hooper Index [stress, fatigue, Delayed Onset Muscle Soreness (DOMS) and sleep]; and (c) to compare those variations between playing positions and player status. Nineteen players (24.1 ± 2.7 years) from a Portuguese BPI League professional team participated in this study. All variables were collected in a 10-week in-season period with three training sessions and one match per week during the 2019/20 season. Considering the overall team, the results showed that there were some associations between Hooper Index categories and s-RPE like stress or fatigue (0.693, p < 0.01), stress or DOMS (0.593, p < 0.01), stress or s-RPE (-0.516, p < 0.05) and fatigue or DOMS (0.688, p < 0.01). There were no differences between all parameters in playing positions or player status. In conclusion, the study revealed that higher levels of fatigue and DOMS occur concurrently with better nights of sleep. Moreover, any in-season variations concerning internal load and perceived wellness seems independent of position or status in outfield players. The data also showed that the higher the players' reported stress, the lower the observed s-RPE, thus possibly indicating a mutual interference of experienced stress levels on the assimilation of training intensity by elite women soccer players.

Does observance of Ramadan affect sleep in athletes and physically active individuals? A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to provide an accurate description of the effect of Ramadan observance on sleep duration, sleep quality, daily nap duration, and daytime sleepiness in athletes and physically active individuals. Five electronic databases (PubMed, Web of Science, Scopus, Wiley, and Taylor and Francis) were used to search for relevant studies conducted with athletes or physically active individuals during Ramadan, published in any language, and available before May 23, 2021. Studies that included assessments of sleep quantity and/or quality, and/or daytime sleepiness, and/or daily naps in athletes and physically active individuals were included. The methodological quality of the studies was assessed using "QualSyst". Of the 18 papers included in this study (298 participants in total), 14 were of strong quality, two were moderate, and the remaining two were rated as weak. Individuals who continued to train during Ramadan experienced a decrease in sleep duration (number of studies, K = 17, number of participants, N = 289, g = -0.766, 95% confidence interval [CI] -1.199 to -0.333, p = 0.001). Additionally, the global score of the Pittsburgh Sleep Quality Index increased from 4.053 (K = 5, N = 65, 95% CI 3.071-5.034) pre-Ramadan, to 5.346 (95% CI 4.362-6.333) during Ramadan, indicating a decrease in sleep quality. The duration of daytime naps increased during compared to pre-Ramadan (K = 2, N = 31, g = 1.020, 95% CI 0.595-1.445, p = 0.000), whereas Epworth Sleepiness Scale scores remained unchanged during versus pre-Ramadan (K = 3, N = 31, g = 0.190, 95% CI -0.139-0.519, p = 0.257). In conclusion, individuals who continued to train during Ramadan experienced a decrease in sleep duration, impairment of sleep quality, and increase in daytime nap duration, with no change in daytime sleepiness levels.

Decreased Sleep and Subjective Well-Being as Independent Predictors of Injury in Female Collegiate Volleyball Players

Background:

The relationship among sleep duration, subjective well-being, and injury risk in athletes is poorly defined.

Purpose:

To evaluate the independent effects of sleep duration, sleep quality, and subjective well-being on in-season injuries in collegiate female volleyball athletes.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

During a 9-month competitive season, 17 female National Collegiate Athletic Association (NCAA) Division I volleyball players reported mood, fatigue, stress, soreness, sleep duration (hours), and sleep quality every morning. Well-being measures were recorded from 0 (worst) to 5 (best), and all time-loss injuries were recorded by the team athletic trainer. Separate mixed-effects logistic regression models were used to evaluate the effects of sleep and subjective well-being on in-season injury. Each well-being variable was also included in a separate mixed-effects logistic regression model with sleep duration as a covariate.

Results:

A total of 54 injuries were recorded during the study period. Compared with days without an injury, mood, fatigue, stress, soreness, sleep quality, and sleep duration were significantly worse the day before an injury occurred. In the separate prediction models, in-season injury was significantly predicted by fatigue (odds ratio [OR], 0.56 [95% CI, 0.36-0.86]; P = .008), mood (OR, 0.52 [95% CI, 0.35-0.78]; P = .002), stress (OR, 0.63 [95% CI, 0.42-0.94]; P = .023), soreness (OR, 0.54 [95% CI, 0.38-0.79]; P = .001), sleep quality (OR, 0.49 [95% CI, 0.34-0.7]; P < .001), and sleep duration (OR, 0.69 [95% CI, 0.55-0.87]; P = .001). In the multivariable models, sleep duration remained a significant independent predictor in each of the subsequent multivariable models (OR, 0.72-0.74; P < .05 for all), as did mood (OR, 0.55 [95% CI, 0.36-0.83); P = .005) and soreness (OR, 0.57 [95% CI, 0.39-0.83]; P = .003), while fatigue (OR, 0.65 [95% CI, 0.42-1]; P = .054) and stress (OR, 0.68 [95% CI, 0.45-1]; P = .061) no longer reached statistical significance.

Conclusion:

Increased sleep duration, mood, and decreased soreness were independently associated with a reduced risk of in-season injury in this cohort of female NCAA volleyball players.

Contemporary Variables that Impact Sleep and Development in Female Adolescent Swimmers and Gymnasts

The effects of sleep on elite athletes in late adolescence and early adulthood have been well documented in a myriad of sports. However, there is underrepresentation of pre-pubertal and young female adolescent athlete research between the ages of 11-17, and specifically female gymnast and swimmers. Neglecting to understand how high energy demand at a young age relates to sleep and restoration may lead to developmental ramifications for this group, as they display physiological dysfunctions like delayed puberty, amenorrhea and are at risk for the female athlete triad or components of the triad. This review aims to summarize the contemporary variables of blue light emitting screens, social media, and caffeine on quality and quantity of sleep in young athletes while identifying gaps in the literature on how these factors impact the target group of young female swimmers and gymnasts.  The implications of this work include sleep hygiene recommendations for increasing duration and quality of sleep, as well as future research with respect to electronic device usage, social media participation, caffeine consumption, and sport engagement in female early adolescent athletes.

Relationships between Sleep, Athletic and Match Performance, Training Load, and Injuries: A Systematic Review of Soccer Players

The purpose of this systematic review was to summarize available evidence regarding the relationships between sleep and (i) athletic and match performance, (ii) training load, and (iii) injuries in soccer players. A systematic review of EBSCOhost (SPORTDiscus), PubMed, Cochrane Library, FECYT (Web of Sciences, CCC, DIIDW, KJD, MEDLINE, RSCI, and SCIELO) databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 297 titles were identified, of which 32 met the eligibility criteria. Results revealed that soccer players are no exception for sleep inadequacy. Although there was inconsistency in the findings, some studies suggested that sleep restrictions in soccer negatively affected athletic and match performance while also increasing the number and severity of musculoskeletal injuries. On the other hand, inconsistent results were found between sleep and athletic and match performance, and training load in soccer players. Physiological responses (and their intensity) during drill-based games were not influenced by changes in sleep. The available evidence is inconsistent; however, it appears to suggest that poor sleep affects soccer players' performance and increases the risk of injury. However, it remains important to study this complex relationship further.

Evidence That Sleep Is an Indicator of Overtraining during the Competition Phase of Adolescent Sprinters

Although sleep disturbance is a common complaint in overtrained athletes, the role of sleep in the overtraining process is not clear. This study aimed (i) to compare sleep efficiency/quantity at the start of a competition phase in elite adolescent sprinters who adapted to prior training with that in those who maladapt and (ii) to examine the influence of prior training, fatigue, and sleep on performance through a moderated mediation model. Fatigue (via Profile of Mood State) and internal training load (via session rating of perceived exertion and duration of training as volume) were measured in 20 sprinters (mean age: 15.9 ± 1.7 years) across 4 mesocycles (baseline (T1); preparatory (T2); precompetitive (T3); and competitive (T4) phases), over 26 weeks. Performances were assessed during the competitive period (T3, T4), while sleep was monitored (via actigraphy) for a week during T4. It was inferred that sprinters who had increasingly greater fatigue and concomitant decrements in performance (35%) were maladapted to training and the remaining sprinters who improved fatigue and performance (65%) were adapted to training. Sleep efficiency (91 ± 3% vs. 82 ± 3%, p < 0.001) and quantity (425 ± 33 min vs. 394 ± 20 min, p < 0.001) at the start of T4 were significantly greater in sprinters who adapted. Moreover, higher prior training volume (mean of T1 to T3 training volume) was associated with lower sleep efficiency at the start of T4 (R² = 0.55, p < 0.001) which was associated with poorer performance (R² = 0.82, p < 0.001). Fatigue moderated the indirect effect of prior training volume on performance through its moderation of the effect of sleep efficiency on performance (R² = 0.89, p < 0.001). Impaired sleep as a result of greater prior training volume may be related to performance decrements through fatigue. Athletes should improve sleep during periods of higher training volume to reduce fatigue for better adaptation to training.

Insufficient Sleep in Young Athletes? Causes, Consequences, and Potential Treatments

Sleep is essential in the preparation for, and the recovery from, training and competition. Despite being important for all individuals, young athletes are considered an at-risk group for reduced sleep duration and quality. The purpose of this review is to synthesise current literature relating to sleep duration and quality in young (14-25 years) athletes. Specifically, typical sleep and wake patterns, factors affecting sleep and wake patterns, and the consequences of altered sleep and wake patterns in young athletes are discussed. Scheduling training and competition in the afternoon or evening appears to result in reduced sleep duration due to less time in bed. Evidence suggests that young athletes who obtain less than 8 h of sleep per night are at a higher risk of musculoskeletal injury. An increase in sleep duration above habitual nightly sleep may be associated with favourable performance in young athletes; however, the associations between sleep quality and performance- and health-related outcomes remain unclear.

Impact of in-season injury on quality of life and sleep duration in female youth volleyball athletes: a prospective study of 2073 players

OBJECTIVES

The psychological impacts of injuries in youth athletes remain poorly defined. The purpose of this study was to evaluate the influence of injury on quality of life (QOL) and sleep in female high school volleyball athletes.

METHODS

2073 female high school volleyball players (15.6±1.1 years) completed the Pediatric Quality of Life survey (total QOL, physical, social, school, emotional and psychosocial function) and reported average sleep duration at the start and end of the season. Injury data were collected by school athletic trainers. Mixed effects linear regression models were used to compare changes in QOL and sleep duration during the season between (1) injured and uninjured athletes and (2) injured athletes who did or did not suffer a season-ending injury.

RESULTS

Time-loss injuries were reported in 187 athletes with complete preseason and postseason data. During the season, injured athletes demonstrated a greater decrease in total QOL (β=-1.3±0.5, p=0.012), as well as physical function (β=-1.6±0.6, p=0.012), school function (β=-2.0±0.76, p=0.01) and psychosocial function domains (β=-1.2±0.6, p=0.039) compared with uninjured athletes. Athletes who sustained a season-ending injury had a significantly greater decrease in total QOL (β=-6.8±2.0, p=0.006) and physical function (β=-17±2.9, p<0.001) compared with injured athletes who were able to return to play during the season.

CONCLUSION

In-season injuries are associated with significant decreases in total QOL as well as physical and psychosocial function. Healthcare providers should consider the impacts of injuries on QOL and sleep in youth athletes in order to optimise management and improve overall health.

Decreased Sleep Is an Independent Predictor of In-Season Injury in Male Collegiate Basketball Players

Background:

Although decreased sleep has been associated with decreased performance, increased illness risk, and impaired well-being in athletes, the relationship between sleep and injury risk in collegiate athletes is unknown.

Purpose/Hypothesis:

To evaluate the independent effects of sleep duration and subjective well-being on in-season injury in male collegiate basketball athletes. We hypothesized that decreased sleep would be associated with an increased risk of in-season injury.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

During 2 consecutive seasons, 19 male National Collegiate Athletic Association Division I basketball players reported mood, fatigue, stress, soreness, sleep duration (hours), and previous day’s training load every morning. Well-being measures were recorded on a scale from 0 (worst) to 5 (best), and all time-loss injuries were recorded by the team athletic trainer. Separate mixed-effects logistic regression models were used to evaluate the effects of sleep and subjective well-being on in-season injury, with adjustment for same-day training load and individual repeated measures. To determine the independence of sleep and well-being as predictors of injury, each well-being variable was included in a separate mixed-effects logistic regression model, with sleep and training load as covariates.

Results:

During the study period, 32 injuries were recorded. In the initial separate prediction models, in-season injury was significantly predicted by mood (odds ratio [OR], 0.50; 95% CI, 0.37-0.66), fatigue (OR, 0.44; 95% CI, 0.33-0.59), stress (OR, 0.57; 95% CI, 0.42-0.76), soreness (OR, 0.41; 95% CI, 0.32-0.54), and sleep duration (OR, 0.57; 95% CI, 0.49-0.66) (P < .001 for all). In the multivariable models, sleep duration remained a significant, independent predictor in each of the subsequent multivariable models (OR, 0.52-0.69; P < .001 for all) as did soreness (OR, 0.65; 95% CI, 0.44-0.95; P = .024), whereas mood (OR, 1.2; 95% CI, 0.76-1.9; P = .43), fatigue (OR, 1.1; 95% CI, 0.65-1.9; P = .68), and stress (OR, 1.1; 95% CI, 0.75-1.5; P = .69) were no longer significant.

Conclusion:

Increased sleep duration is independently associated with a reduced risk of in-season injury in male collegiate basketball players, even after adjustment for training load and subjective well-being. The effects of mood, fatigue, and stress on injury were no longer evident after adjustment for the effect of sleep duration.

Special Considerations for Growing Dancers

Care of young dancers requires a unique approach during a critical time of growth and development. Young dancers' well-being depends on factors including sleep, mental health, growth-associated musculoskeletal imbalances, and nutrition. Puberty is a particularly important time for young dancers. It coincides with an increased commitment to their art form and physical/psychosocial changes. It is imperative for practitioners to understand these various factors in order to optimize young dancers' health and allow them to safely train and perform.

Discrepancies between self-reported current and ideal sleep behaviors of adolescent athletes

It is well documented that many adolescents are not meeting current sleep duration recommendations, with a growing body of literature suggesting adolescent athletes also fall into this category. What is less known is the relationship between current and ideal sleep behaviors. We sought to quantify sleep behaviors in a group of athletes and to understand how their current behaviors compare to their self-reported ideal behaviors. One hundred ninety six competitive, male and female athletes (15.7 ± 1.3 y) completed the Pittsburgh Sleep Quality Index (PSQI) and a questionnaire that captured usual sleep habits. The PSQI was analyzed for habitual bedtime, wake time, sleep duration, and sleep quality. The usual sleep habits questionnaire was analyzed for ideal bedtime, wake time, and calculated sleep duration. Reported mean sleep duration was 7:45 ± 1:06 h:min. Actual bedtime was later (+0:44 ± 0:05 h:min, p<0.001) than ideal bedtime, actual wake time was earlier (-0:50 ± 0:08 h:min, p<0.001) than ideal wake time, and actual sleep duration was less (-2:11 ± 1:27 h:min, p<0.001) than ideal sleep duration. Adolescent athletes are not meeting current sleep duration recommendations and there are significant discrepancies between self-reported current and ideal sleep behaviors in this group.

Decreased Physical Activity and Sleep, Not Sport Specialization, Predict Illness in Middle School Athletes

BACKGROUND

The relationships between sport specialization, physical activity, sleep, and illness in younger athletes are unknown. Therefore, the purpose of this study was to evaluate the independent effects of sport specialization, sleep, and physical activity on illness in middle school athletes.

HYPOTHESIS

Decreased sleep, decreased physical activity, and higher levels of sport specialization will be associated with an increased risk of illness among middle school athletes.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Parents of middle school-aged children reported baseline sport specialization (low, moderate, or high) as well as sleep duration, physical activity, and illnesses every week throughout the academic year. A mixed-effects logistic regression model was used to assess the association between illness and specialization while accounting for sleep and physical activity for the prior week as fixed effects and each individual as a random effect.

RESULTS

A total of 233 children (mean age, 12.1 ± 1.2 years; 61% male) participated, of whom 41%, 25%, and 34% were categorized as low, moderate, and high specialization, respectively. The proportion of individuals who experienced illness did not differ by specialization level (low, 76%; moderate, 70%; high, 59%; P = 0.064). In the multivariable model, the odds of illness compared with the low specialization group was not significantly different for moderate (odds ratio [OR], 0.93; 95% CI, 0.70-1.23; P = 0.61) or high specialization (OR, 0.76; 95% CI, 0.56-1.03; P = 0.073). A decreased risk of illness was associated with greater prior week sleep (OR, 0.79; 95% CI, 0.69-0.91; P < 0.001) and physical activity (OR, 0.94; 95% CI, 0.92-0.96; P < 0.001).

CONCLUSION

Sport specialization is not associated with an increased risk of illness among middle school athletes, while increased sleep duration and physical activity appear to reduce the risk of illness.

CLINICAL RELEVANCE

Interventions to promote physical activity and improve sleep may reduce the risk of illness in early adolescent athletes.

Sleep debt induces skeletal muscle injuries in athletes: A promising hypothesis

Sleep is a physiological state and it is fundamental for physical and cognitive recovery of athletes. Due to strenuous training and competitions, athletes may present sleep complaints compromising good quality and quantity of sleep. Studies have related sleep debt to the occurrence of musculoskeletal injuries in athletes, but the mechanisms that can lead to this are not entirely clear. Studies involving animals and humans have shown that poor sleep quality can cause significant changes in hormones and cytokines. Demonstrating that this hormones changes lead to a decrease of testosterone and growth hormone levels and increased cortisol levels, important hormones in the process of protein synthesis and degradation. In athletes, the sport itself is a risk factor of injuries, and sleep debt may result in overtraining syndrome associated with inflammatory markers and ultimately to immune system dysfunction. Thus, we hypothesize that athletes who have sleep debt are more susceptible to musculoskeletal injuries due to increased catabolic pathway signaling, i.e. protein degradation and decreased anabolic pathway signaling, compromising muscle integrity. In this sense, we indicate the relationship between musculoskeletal injuries and sleep debt involving new targets for immunological signaling pathways that start the reduction of the muscle recovery process.

Poor Sleep Quality's Association With Soccer Injuries: Preliminary Data

PURPOSE

To investigate the relationship between sleep quality and quantity and injuries in elite soccer players and to compare sleep-wake variables and injury characteristics.

METHODS

The current investigation was a prospective cohort study of 23 elite male soccer players competing for 2 teams over 6 mo in the highest-level Brazilian competition. The players' sleep behavior was monitored for 10 d in the preseason using self-reporting sleep diaries and wrist activity monitors to determine sleep duration and quality. Furthermore, injuries were recorded by the respective club's medical teams into a specific database. Details of injuries recorded included the type, location, and severity of each injury. The results were expressed as descriptive statistics, and the significance level was set at 5%. The Mann-Whitney U test was performed to compare the sleep variables between groups. Spearman correlation coefficient and linear-regression analysis were used.

RESULTS

The results indicated a moderate negative correlation between sleep efficiency and particular injury characteristics, including absence time, injury severity, and amount of injuries. The linear-regression analysis indicated that 44% of the total variance in the number of injuries can be explained by sleep efficiency, 24% of the total variance in the absence time after injury (days) can be explained by sleep efficiency, and 47% of the total variance in the injury severity can be explained by sleep efficiency.

CONCLUSIONS

Soccer players who exhibit lower sleep quality or nonrestorative sleep show associations with increased number and severity of musculoskeletal injuries.

Sleep Quality and Quality of Life Among Healthy High School Athletes

We examined the association between sleep quality and quality of life (QOL) among uninjured high school athletes. Participants completed the Pittsburgh Sleep Quality Index (PSQI) and the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Profile 25 questionnaire. One hundred ten athletes reported poor sleep quality (mean PSQI: 6.6 ± 2.0; mean age: 15.3 ± 1.1; 62% female); 162 athletes reported good sleep quality (mean PSQI: 2.3 ± 1.3; mean age: 15.1 ± 1.7; 33% female). After adjusting for sex and age, worse sleep quality was associated with higher physical function/mobility (β = 0.034; 95% confidence interval [CI] = 0.007-0.060; P = .01), anxiety (β= 0.391; 95% CI = 0.263-0.520; P < .001), depressive symptom (β = 0.456; 95% CI = 0.346-0.565; P < .001), fatigue (β = 0.537; 95% CI = 0.438-0.636; P < .001), pain interference (β = 0.247; 95% CI = 0.119-0.375; P < .001), and pain intensity (β = 0.103; 95% CI = 0.029-0.177; P = .006) ratings. Poor self-reported sleep quality among adolescent athletes was associated with worse QOL ratings. Clinicians should consider assessing sleep hygiene to provide guidance on issues pertaining to reduced QOL.

Soccer Injuries in Children and Adolescents

Participation in youth soccer in the United States continues to increase steadily, with a greater percentage of preadolescent participants than perhaps any other youth sport. Despite the wide-ranging health benefits of participation in organized sports, injuries occur and represent a threat to the health and performance of young athletes. Youth soccer has a greater reported injury rate than many other contact sports, and recent studies suggest that injury rates are increasing. Large increases in the incidence of concussions in youth soccer have been reported, and anterior cruciate ligament injuries remain a significant problem in this sport, particularly among female athletes. Considerable new research has identified a number of modifiable risk factors for lower-extremity injuries and concussion, and several prevention programs have been identified to reduce the risk of injury. Rule enforcement and fair play also serve an important role in reducing the risk of injury among youth soccer participants. This report provides an updated review of the relevant literature as well as recommendations to promote the safe participation of children and adolescents in soccer.

The Psychosocial Implications of Sport Specialization in Pediatric Athletes

Data on the psychosocial implications of sport specialization in pediatric athletes are lacking. Sport specialization often requires increased training hours and may predispose young athletes to social isolation, poor academic performance, increased anxiety, greater stress, inadequate sleep, decreased family time, and burnout. Sport specialization frequently introduces multiple stressors that could be expected to adversely affect mental health and function in young athletes and may increase the risk for burnout. This may be confounded by altered sleep duration and quality, increased drive for elite status, and perfectionistic personality types. The signs and symptoms of burnout in young athletes can be difficult to detect. It is important to be aware of the possible diagnosis of burnout in young athletes who display vague symptoms and a decrease in academic performance. The purpose of this review was to survey the available literature on sport specialization in young athletes and its association with mental health, sleep, the drive for success in sport, and burnout.

Relationships Between Sport Specialization, Sleep, and Subjective Well-Being in Female Adolescent Athletes

OBJECTIVE

To evaluate the relationship between sport specialization, sleep, and subjective well-being in female youth soccer players.

DESIGN

Prospective cohort study.

SETTING

Community soccer organization.

METHODS

During a 4-month season, 52 female youth soccer players (aged 13-18 years) reported daily training load (TL) and every morning recorded sleep duration and stress, mood, fatigue, soreness, and sleep quality from -3 (worst) to +3 (best). As all the athletes participate in soccer as their primary sport for over 8 months of the year, players were considered specialized if they participated in soccer exclusively and had previously quit another sport to focus on soccer. Least-square mean values from linear mixed effects models were used to compare TL, subjective well-being, and sleep while adjusting for individual repeated measures.

RESULTS

Daily TL during the season did not differ between specialized and nonspecialized athletes (412 ± 24 vs 415 ± 19 arbitrary units, P = 0.96, respectively). Despite similar nightly sleep duration (8.10 ± 0.14 vs 8.25 ± 0.11 hours, P = 0.42), specialized athletes were found to have lower (worse) fatigue (1.02 ± 0.14 vs 1.50 ± 0.11, P = 0.010), soreness (0.66 ± 0.18 vs 1.23 ± 0.14, P = 0.013), mood (1.32 ± 0.12 vs 1.72 ± 0.10, P = 0.013), and sleep quality (1.07 ± 0.13 vs 1.42 ± 0.10, P = 0.035) than the nonspecialized group. Although stress was lower (worse) among the specialized athletes, the difference was not statistically significant (0.97 ± 0.16 vs 1.32 ± 0.13, P = 0.092).

CONCLUSIONS

Among female youth soccer players, sport specialization was associated with impairments in subjective well-being and sleep quality. Additional research is necessary to determine whether this relationship is causal or if factors that influence sport specialization also influence sleep and subjective well-being.