Effect of daily mindfulness fluctuations on sleep and recovery-stress states in elite level judoka: an observational study

Introduction

Sleep is a fundamental factor in an athlete's ability to sustain peak performance and endurance. Mindfulness, defined as a state of intentional, non-judgmental awareness of the present moment, has been linked to positive effects on sleep. The present study aims to investigate which recovery and sleep parameters are influenced by interindividual differences in mindfulness tendencies and intraindividual daily fluctuations in mindfulness.

Methods

A two-week continuous monitoring study was conducted with 33 elite-level judoka (17 female, 16 male; age: M = 23.79, SD = 3.05) competing at the national and international level. Data collection included objective sleep monitoring via actigraphy and subjective monitoring through morning and evening self-report questionnaires. Sleep was analyzed as a function of both trait and daily mindfulness, as well as behavioral factors such as the number of training sessions, session intensity, and the implementation of recovery activities and naps.

Results

Multilevel analyses revealed significant positive associations between mindfulness and qualitative subjective sleep parameters, as well as morning and evening recovery-stress states. Among the mindfulness facets, acting with awareness emerged as the strongest predictor. In terms of quantitative sleep parameters, mindfulness influenced both subjective and objective sleep latencies.

Discussion

The findings suggest that mindfulness may play a key role in sleep regulation among athletes, particularly in enhancing perceived restfulness, improving recovery-stress states in the evening and morning, and facilitating the process of falling asleep. These results highlight mindfulness as a promising target for interventions aimed at improving subjective recovery and reducing sleep onset latencies through daily mindful behaviors. Furthermore, the study underscores the relative independence of qualitative and quantitative sleep parameters, suggesting they are influenced by distinct factors.

Sleep-wake patterns of fencing athletes: a long-term wearable device study

Objective

Sleep is the most efficient means of recovery for athletes, guaranteeing optimal athletic performance. However, many athletes frequently experience sleep problems. Our study aims to describe the sleep-wake patterns of fencing athletes and determine whether factors, such as sex, competitive level and training schedules, could affect the sleep-wake rhythm.

Methods

Sleep data from 23 fencing athletes were collected using the Huawei Band 6, monitoring key sleep parameters such as bedtime, wake time, duration of deep and light sleep, wake periods, REM sleep duration, and nap duration. During this period, athletes were required to wear the band continuously for 24 hours daily, except bathing, charging, and competition times.

Results

Athletes averaged 7.97 hours of sleep per night, with significant differences observed in wake time (p = 0.015) and midpoint of sleep (p = 0.048) between high-level and low-level athletes, as well as a higher frequency of naps among high-level (χ2 = 11.97, p = 0.001) and female (χ2 = 3.88, p = 0.049) athletes. Nap duration was negatively correlated with night sleep duration (r =  - 0.270, p < 0.001). Athletes were observed for changes in sleep-wake patterns from Monday to Sunday. On Mondays, Wednesdays, and Fridays, when there was no morning training, the athletes' wake-up time and the midpoint of sleep were shifted significantly backward, and there were significant differences in sleep parameters between training days and rest days.

Conclusion

The sleep patterns of athletes differ according to level and gender. The sleep-wake patterns of athletes are influenced by training schedules, indicating the presence of sleep rhythm disruption.

The Impact of Daytime Napping Following Normal Night-Time Sleep on Physical Performance: A Systematic Review, Meta-analysis and Meta-regression

BACKGROUND

Daytime napping is used by athletes as a strategy to supplement night time sleep and aid physical performance. However, no meta-analytical overview regarding the impact of napping following a night of normal sleep (7-9 h) on physical performance is available.

OBJECTIVE

The aim of this study was to evaluate the effect of daytime napping following normal night-time sleep on physical performance in physically active individuals and athletes.

METHODS

This systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Seven electronic databases (i.e., PubMed, Web of Science, Scopus, SPORTDiscus, CINAHL, SCIELO, and EBSCOhost) were used to search for relevant studies that investigated the impact of daytime napping, following normal night-time sleep, on physical performance in physically active individuals and athletes, published in any language, and available before September 01, 2022. Studies that included assessments of any physical performance measures were included. QualSyst was used to assess the methodological quality of the studies.

RESULTS

Of 18 selected articles, 15 were of strong quality and 3 were of moderate quality. Compared with no-nap conditions, physically active individuals and athletes who napped experienced an increase in highest distance (effect size [ES] 1.026; p < 0.001) and total distance (ES 0.737; p < 0.001), and a decrease in fatigue index (ES 0.839, p = 0.008) during the 5-m shuttle run test (5MSRT). However, napping yielded no effect on muscle force (ES 0.175; p = 0.267). No effect of napping was found in one study that measured sprint performance and in two studies that measured performance during the 30-s Wingate test. Two of three studies reported an increase in jump performance after napping. Two of three studies reported an increase in repeated sprints after napping. One study reported an increase in upper-body power performance after napping, and napping was beneficial for endurance performance in one of two studies.

CONCLUSION

Following normal sleep, napping is beneficial for the performance of the 5MSRT, with no significant effect on muscle force. No firm conclusions can be drawn regarding other physical performance measures due to the limited number of studies.

Circadian rhythm in sportspersons and athletic performance: A mini review

Circadian rhythms in the physiological and behavioral processes of humans play a crucial role in the quality of living and also in the magnitude of success and failure in various endeavors including competitive sports. The rhythmic activities of the body and performance in sportspersons do have a massive impact on their every cutthroat competition. It is essential to schedule sports activities and training of players according to their circadian typology and time of peak performance for improved performance and achievement. In this review, the focus is on circadian rhythms and diurnal variations in peak athletic performance in sportspersons. Accuracy and temporal variability in peak performance in an individual could be attributed to various factors, namely chronotype, time of the day, body temperature, jetlag, hormones, and prior light exposure. Circadian rhythm of mood, alertness, T-core, and ultimately athletic performance is not only affected by sleep but also by circadian variations in hormones, such as cortisol, testosterone, and melatonin. There are, however, a few reports that are not consistent with the conclusions drawn in this review. Nevertheless, circadian rhythm and performance among sportspersons and athletes are important areas of research. This review might be useful to the managers and policymakers associated with competitive sports and athletic events.

Association between daytime nap duration and risks of frailty: Findings from the China Health and Retirement Longitudinal Study

Introduction

Night sleep duration and total sleep duration are associated with frailty. However, the association between daytime nap duration and the risks of frailty has not been explored thoroughly.

Methods

This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Participants aged 60 years and older at baseline were included in this study. Individuals with daytime nap duration were categorized into four groups: no napping, short napping (< 30 min), moderate napping (30-89 min), and extended napping (≥90 min). Frailty was assessed using a modified Physical Frailty Phenotype (PFP) scale. Non-frail participants at baseline were followed up for 4 years. The association between nap duration and risks of frailty at baseline and incident frailty was evaluated by logistic regression and discrete-time Cox regression analyses, respectively.

Results

In total, 5,126 participants were included in this study. For individuals with night sleep duration of ≥9 h, short nappers showed higher odds [odds ratio (OR) = 4.08, 95% confidence interval (CI): 1.30-12.78] for frailty compared with non-habitual nappers at baseline, while moderate nappers were less likely to be frail (OR = 0.18, 95% CI: 0.04-0.73). In the follow-up study, short nappers showed higher risks for frailty compared with participants of the no napping group with night sleep duration of < 6 h [hazard ratio (HR) = 1.91, 95% CI: 1.07-3.43] or 6-9 h (HR = 1.97, 95% CI: 1.18-3.30). Compared with short nappers, older adults with extended napping (HR = 0.41, 95% CI: 0.22-0.77) showed lower risks for frailty in those with night sleep duration of 6-9 h. For individuals with night sleep duration of ≥9 h, moderate napping (HR = 0.20, 95% CI: 0.05-0.77) decreased the risks for frailty compared with short napping.

Conclusion

Among older adults with night sleep duration of < 9 h, short nappers posed higher risks for frailty compared with non-habitual nappers. Extended naps for those with a night sleep duration of 6-9 h or moderate naps for those with night sleep duration of ≥9 h could lower the risk of frailty compared with short naps. Future studies on the timing, purpose, frequency, and quality of daytime napping and objectively measured nap duration are needed to explore the association between daytime napping and risks of frailty.

Benefits and risks of napping in older adults: A systematic review

A growing body of evidence indicates that napping is common among older adults. However, a systematic review on the effect of napping on the elderly is lacking. The aim of this systematic review was to (i) determine how studies evaluated napping behavior in older adults (frequency, duration and timing); (ii) explore how napping impacts perceptual measures, cognitive and psychomotor performance, night-time sleep and physiological parameters in the elderly (PROSPERO CRD42022299805). A total of 738 records were screened by two researchers using the PICOS criteria. Fifteen studies met our inclusion criteria with a mean age ranging from 60.8 to 78.3 years and a cumulative sample size of n = 326. Daytime napping had an overall positive impact on subjective measures (i.e., sleepiness and fatigue), psychomotor performances (i.e., speed and accuracy) and learning abilities (i.e., declarative and motor learning). Additionally, studies showed (i) consistency between nap and control conditions regarding sleep duration, efficiency and latency, and proportion of sleep stages, and (ii) increase of 24 h sleep duration with nap compared to control condition. Based on the findings of the present review, there is minimal evidence to indicate that napping is detrimental for older adults' nighttime sleep. Future studies should consider involving repeated naps during a micro-cycle in order to investigate the chronic effect of napping on older adults.

Systematic review registration

identifier: CRD42022299805.

Association of Fatigue With Sleep Duration and Bedtime During the Third Trimester

PURPOSE

To investigate the association between fatigue and sleep habits of pregnant women to further explore the effect of sleep duration and bedtime on fatigue during the third trimester.

MATERIALS AND METHODS

A total of 465 Chinese Han pregnant women in the third trimester (after 28 weeks) with a singleton gestation were recruited. Sleep habits (such as bedtime, sleep onset latency, and night sleep duration) and the 14-item Fatigue Scale scores (FS-14, used to assess fatigue) were collected.

RESULTS

The effects of sleep duration and bedtime on FS-14 physical and total scores were significant. FS-14 physical scores and total scores of the participants in the group of sleep before 23 o'clock (SBC) of short sleep duration (<7 h) were significantly higher as compared to the participants in the group of SBC of normal sleep duration, and those of the participants in the group of SBC of normal sleep duration were significantly lower than the participants in the group of sleep after 23 o'clock of normal sleep duration. There were negative correlations of sleep duration with FS-14 physical score and total score in the SBC of short sleep duration group.

CONCLUSION

Sleep less than 7 h or bedtime after 23 o'clock was associated with increased fatigue levels of pregnant women in the third trimester. Therefore, it is necessary to develop good sleep habits (enough sleep duration and early bedtime) to keep fatigue at a low level for pregnant women in the third trimester.

Longer Nap Duration During Ramadan Observance Positively Impacts 5-m Shuttle Run Test Performance Performed in the Afternoon

It is well-documented that changes in the rhythm of life during Ramadan affect sleep schedules (i.e., interruption of night sleep patterns) and are likely to have negative effects on physical and cognitive performances. The aim of the present study was to examine the effect of different naps opportunities' durations during Ramadan on performance of short-duration repetitive maximal exercise and perception of effort. Fifteen physically active men (age: 21 ± 3 years, height: 177 ± 6 cm, body-mass: 73 ± 10 kg) performed a 6 × 30-s shuttle run test after a 25-min nap (N25), a 45-min nap (N45), and in a no-nap condition (NN) during three experimental periods: ∼2 weeks before Ramadan (BR), the last ten days of Ramadan (ER), and ∼3 weeks after Ramadan (AR). During the shuttle run test performed in the late afternoon, the greatest distance (GD), the total distance (TD) and a fatigue index (FI) were assessed. Rating of perceived exertion (RPE) was determined after each 30-s effort. Dietary intake and sleep quality were assessed in each of the three periods. Compared to BR, GD and TD were lower in the ER testing period (p = 0.005; d = 0.54) but returned to BR levels in the AR period. During ER, carbohydrate intake was lower (p = 0.04; d = 0.2), and sleep duration and sleep quality were reduced (d = 0.27 and 0.54, respectively), although other aspects of dietary intake and sleep pattern were not affected. Compared to NN, GD and TD were higher after N25 (d = 0.57 and 0.34, respectively) and N45 (d = 0.93 and 0.88 respectively). RPE was lower in N45 (p = 0.035, d = 0.84). N45 resulted in higher TD (p = 0.021, d = 0.13) and lower RPE (p = 0.004; d = 0.57) compared to N25 during ER. Taking a daytime nap benefits subsequent performance in a shuttle run test, whether sleep the previous night was normal (as in BR) or compromised (as in ER). The benefits of napping were greater after a 45-min nap opportunity than after a 25-min nap opportunity.

The impact of daytime napping on athletic performance - A narrative review

Mid-day napping has been recommended as a countermeasure against sleep debt and an effective method for recovery, regardless of nocturnal sleep duration. Herein, we summarize the available evidence regarding the influence of napping on exercise and cognitive performance as well as the effects of napping on athletes' perceptual responses prior to or during exercise. The existing studies investigating the influence of napping on athletic performance have revealed equivocal results. Prevailing findings indicate that following a normal sleep night or after a night of sleep loss, a mid-day nap may enhance or restore several exercise and cognitive performance aspects, while concomitantly provide benefits on athletes' perceptual responses. Most, but not all, findings suggest that compared to short-term naps (20-30 min), long-term ones (>35-90 min) appear to provide superior benefits to the athletes. The underlying mechanisms behind athletic performance enhancement following a night of normal sleep or the restoration after a night of sleep loss are not clear yet. However, the absence of benefits or even the deterioration of performance following napping in some studies is likely the result of sleep inertia. The present review sheds light on the predisposing factors that influence the post-nap outcome, such as nocturnal sleep time, mid-day nap duration and the time elapsed between the end of napping and the subsequent testing, discusses practical solutions and stimulates further research on this area.

Benefits of Daytime Napping Opportunity on Physical and Cognitive Performances in Physically Active Participants: A Systematic Review

BACKGROUND

Evidence suggests that athletes often experience chronic sleep disturbance. Napping is widely recommended as a safe and non-invasive intervention to counteract the negative effects of partial sleep deprivation. However, systematic reviews on the benefits of napping have yet to be undertaken.

OBJECTIVE

(i) To evaluate the effectiveness of diurnal napping opportunities on athletes' physical and cognitive performance and (ii) to outline how aspects of the study design (i.e., nap duration, exercise protocol, participants' fitness level and previous sleep quantity) can influence the potential effects of napping through a systematic appraisal of the literature.

METHODS

This systematic review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. PubMed, Web of Science and SCOPUS databases were searched up to June 2020 for relevant studies investigating the effect of napping on physical and cognitive performances in physically active participants. Fourteen strong-quality and four moderate-quality (mean QualSyst score = 75.75 ± 5.7%) studies met our inclusion criteria and were included in the final sample (total participants: 158 physically active and 168 athletes).

RESULTS

Most studies (n = 15) confirmed the beneficial effects of napping and showed that diurnal napping improved short-term physical performance (n = 10), endurance performance (n = 3) and specific skills performance (n = 2). Two studies showed no significant napping effect and only one study showed reduced sprint performance following diurnal napping. Moreover, napping improved reaction time (n = 3), attention (n = 2) and short-term memory (n = 1) performances. Importantly, "replacement naps" improved both physical and cognitive performance regardless of the type of exercise. However, "prophylactic naps" improved only jump, strength, running repeated-sprint, attention and reaction time performances. In addition, this systematic review revealed that longer nap opportunities (i.e., 90 min) resulted in better improvement of physical and cognitive performance and lower induced fatigue.

CONCLUSIONS

A diurnal nap seems to be an advantageous intervention to enhance recovery process and counteract the negative effect of partial sleep deprivation on physical and cognitive performance. Particularly, to optimize physical performances of athletes experiencing chronic lack of sleep, findings from the included individual studies suggest 90 min as the optimal nap duration. Diurnal napping may be beneficial for athletes but this benefit should be viewed with caution due to the quality of the evidence, risk of bias and the limited evidence about napping interventions.

Comparison of sleep between youth elite amateur athletes and professional athletes

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

To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance

PURPOSE

The objective of this systematic review was to 1) determine how studies evaluated napping behavior in athletes (frequency, duration, timing and measurement); 2) explore how napping impacted physical performance, cognitive performance, perceptual measures (eg, fatigue, muscle soreness, sleepiness and alertness), psychological state and night-time sleep in athletes.

METHODS

Five bibliographic databases were searched from database inception to 11 August 2020. Observational and experimental studies comprising able-bodied athletes (mean age ≥12 years), published in English, in peer-reviewed journal papers were included. The Downs and Black Quality Assessment Checklist was used for quality appraisal.

RESULTS

Thirty-seven studies were identified of moderate quality. Most studies did not include consistent information regarding nap frequency, duration, and timing. Napping may be beneficial for a range of outcomes that benefit athletes (eg, physical and cognitive performance, perceptual measures, psychological state and night-time sleep). In addition, napping presents athletes with the opportunity to supplement their night-time sleep without compromising sleep quality.

CONCLUSION

Athletes may consider napping between 20 to 90 min in duration and between 13:00 and 16:00 hours. Finally, athletes should allow 30 min to reduce sleep inertia prior to training or competition to obtain better performance outcomes. Future studies should include comprehensive recordings of nap duration and quality, and consider using sleep over a 24 hour period (daytime naps and night-time sleep period), specifically using objective methods of sleep assessment (eg, polysomnography/actigraphy).

Global Research Output on Sleep Research in Athletes from 1966 to 2019: A Bibliometric Analysis

This study examined sleep research in athletes published between 1966 and 2019, through a bibliometric analysis of research output in the Scopus database. Following a robust assessment of titles, the bibliometric indicators of productivity for studies included in the final analysis were: Distribution of publications and citations (excluding self-citations), top ten active journals, countries, institutions and authors, single- and multi-country collaboration, and 25 top-cited papers. Out of the 1015 papers, 313 were included in the final analysis. The majority of the papers were research articles (n = 259; 82.8%) and published in English (n = 295; 94.3%). From 2011, there was a dramatic increase in papers published (n = 257; 82.1%) and citations (n = 3538; 91.0%). The number of collaborations increased after 2001, with papers published through international (n = 81; 25.9%) and national (n = 192; 61.3%) collaboration. Australia was the most prolific country in terms of number of publications (n = 97; 31.0%), and citations (n = 1529; 15.8%). In conclusion, after the beginning of the twenty-first century, the scientific production on sleep research in athletes has seen significant growth in publication and citation output. Future research should focus on interventions to improve sleep in athletes.

Napping in high-performance athletes: Sleepiness or sleepability?

Daytime napping is a common practice in high-performance athletes, and is widely assumed to reflect sleepiness arising from sports-related sleep debt. The possibility that athlete naps may also be indicative of 'sleepability', a capacity to nap on demand that is only weakly related to homeostatic sleep pressure, has not previously been tested. The present study compared daytime sleep latencies in high-performance athletes and non-athlete controls using a single nap opportunity model. Elite (n = 10), and sub-elite (n = 10) athletes, and non-athlete controls (n = 10) attended the laboratory for a first adaption trial, and a subsequent experimental trial. Subjective sleepiness was assessed using the Karolinska Sleepiness Scale (KSS) at 14:00, 14:30 and immediately prior to a 20-minute nap opportunity at 15:00. Sleep latencies were measured using polysomnography, and defined as the time from lights out to the first epoch of any stage of sleep (N1, N2, N3, REM). In unadjusted comparisons with non-athlete controls, elite athletes showed significantly shorter sleep latencies in both the adaptation (p < 0.05) and experimental trials (p < 0.05). These significant differences were maintained in models controlling for pre-trial KSS scores and pre-trial total sleep time (all p < 0.05). Sleep latency scores for sub-elite athletes showed similar trends, but were more labile. These results are consistent with a conclusion that, among elite athletes, napping behaviour can reflect sleepability and may not necessarily result from nocturnal sleep disruption and daytime sleepiness.

The Influence of Match-Day Napping in Elite Female Netball Athletes

Purpose: To assess the effect of match-day napping and duration of naps on perceptual and performance indices in elite female netball players over 2 consecutive netball seasons. Methods: A total of 14 elite female netball athletes (mean [SD]; age = 23 [6] y) participated in an observational study over 26 competition matches. On each match day, athletes provided information on their napping habits and perceived energy levels, then performed 3 countermovement jumps 3 h:30 min prior to the start of the match. One hour after the match, subjective player performance ratings from the players and 2 members of the coaching staff were obtained. Naps were characterized into 3 conditions for analysis: no nap (NN), <20-min nap (SHORT), and ≥20-min nap (LONG). Results: A significant difference in peak jump velocity was observed between the SHORT and the NN condition in favor of the shorter nap (3.23 [0.26] and 3.07 [0.36] m·s−1, respectively, d = 0.34, P < .05). A moderate, significant difference (d = 0.85; P < .05) was observed for the coach rating of performance (out of 10) between the SHORT and the NN condition (7.2 [0.8] and 6.4 [0.9], respectively) in favor of SHORT. Conclusions: The findings from the study would suggest that a short nap (<20 min) on the day of competition can enhance jump velocity and improve subjective performance in elite netball players, as assessed by coaching staff.

From pillow to podium: a review on understanding sleep for elite athletes

Sleep is considered vital to human health and well-being, and is critical to physiological and cognitive functioning. Elite athletes experience high training and competition demands, and are often exposed to various factors, situations, and environments that can cause sleep impairments. Previous research has shown that athletes commonly experience sleep loss in the lead up to and following competition, which could have significant impacts on their preparation, performance, and recovery. In particular, the results from previous research show significant reductions in total sleep time (~1:40 h:min) and significant increases in sleep latency (~45 minutes) following evening competition. Napping is common in both the training and competition setting in athletes; however, research on the effect of napping on physiology and performance is limited. In contrast, research on strategies and interventions to improve sleep are increasing in the athletic population, with sleep hygiene research resulting in significant improvements in key sleep indices. This review investigates the physiological importance of sleep in athletes, current tools to monitor athletes' sleep, the role of sleep for cognitive functioning and athletic performance, the prevalence of sleep disturbances and the potential mechanisms causing sleep disturbances, the role of napping, and different intervention strategies to improve sleep.

Sleep/wake behaviours of elite athletes from individual and team sports

Sleep is an essential component for athlete recovery due to its physiological and psychological restorative effects, yet few studies have explored the habitual sleep/wake behaviour of elite athletes. The aims of the present study were to investigate the habitual sleep/wake behaviour of elite athletes, and to compare the differences in sleep between athletes from individual and team sports. A total of 124 (104 male, 20 female) elite athletes (mean ± s: age 22.2 ± 3.0 years) from five individual sports and four team sports participated in this study. Participants' sleep/wake behaviour was assessed using self-report sleep diaries and wrist activity monitors for a minimum of seven nights (range 7-28 nights) during a typical training phase. Mixed-effects analyses of variances were conducted to compare the differences in the sleep/wake behaviour of athletes from two sport types (i.e. individual and team). Overall, this sample of athletes went to bed at 22:59 ± 1.3, woke up at 07:15 ± 1.2 and obtained 6.8 ± 1.1 h of sleep per night. Athletes from individual sports went to bed earlier, woke up earlier and obtained less sleep (individual vs team; 6.5 vs 7.0 h) than athletes from team sports. These data indicate that athletes obtain well below the recommended 8 h of sleep per night, with shorter sleep durations existing among athletes from individual sports.

Sleep in athletes and the effects of Ramadan

Sleep is now considered as a new frontier in performance enhancement. This article presents background content on sleep function, sleep needs and methods of sleep investigation along with data on the potential effects of Ramadan fasting on sleep in normal individuals and athletes. Accumulated sleep loss has negative impacts on cognitive function, mood, daytime sleepiness and performance. Sleep studies in athletes fasting during Ramadan are very rare. Most of them have demonstrated that during this month, sleep duration decreased and sleep timing shifted. But the direct relation between sleep changes and performance during Ramadan is not yet elucidated. Objective sleep patterns can be investigated using polysomnography, actigraphy, and standardised questionnaires and recorded in daily journals or sleep logs. The available data on sleep indicate that team doctors and coaches should consider planning sleep schedule and napping; implementing educational programmes focusing on the need for healthy sleep; and consider routine screening for sleep loss in athletes of all age groups and genders.