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

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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 skill 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” showed to improve both physical and cognitive performances regardless of the type of exercise. However, “prophylactic naps” showed to only improve jump, strength, running repeated-sprint, attention and reaction time performances. Additionally, 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, in order to optimise 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. https://rdcu.be/clsSL
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Sports Medicine (2021) 51:2115–2146
https://doi.org/10.1007/s40279-021-01482-1
SYSTEMATIC REVIEW
Benefits ofDaytime Napping Opportunity onPhysical andCognitive
Performances inPhysically Active Participants: ASystematic Review
MaherSouabni1 · OmarHammouda1,2 · MohamedRomdhani4,5 · KhaledTrabelsi3,6 · AchrafAmmar1,7 ·
TarakDriss1
Accepted: 23 April 2021 / Published online: 27 May 2021
© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021
Abstract
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. Impor-
tantly, “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 physi-
cal 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.
* Tarak Driss
tarak.driss@parisnanterre.fr
Extended author information available on the last page of the article
1 Introduction
Athletes, coaches, sport scientists and medical staff are
facing the challenge to ensure that the required intensity
and duration of training do not cause injury, over-reach-
ing, or overtraining. The key is to find the perfect balance
between training load and the appropriate recovery to allow
improvement [1]. In this way, sleep is widely considered
to be essential for optimal performance, general health and
recovery [2, 3]. While at least 7h of sleep is recommended
for healthy adults [4, 5], research suggests that athletes
need 9–10h of total sleep time (TST) for optimal waking
functioning [6]. Nonetheless, despite the clear need for ath-
letes to obtain adequate sleep, all indications are that sleep
disturbances are frequent among athletes [7, 8]. A recent
systematic review and meta-analysis concluded that elite
athletes’ sleep may be more disturbed than normal due to
several reasons. Jetlag, altitude, early morning training,
increases in training load and traveling to sport meetings
might involve getting up early in the morning or retiring
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The effect of daytime napping on performance among physically active people has been the topic of several recent studies (Botonis et al., 2021;Lastella et al., 2021;Souabni et al., 2021). Accordingly, a systematic review of the literature on the effect of daytime napping on cognitive and physical performance among older adults is warranted. ...
... This phenomenon is called post-lunch dip and is characterized by a dip in performance for some variables during mid-afternoon hours (Monk, 2005), especially for people who have been partially deprived of sleep (Romdhani et al., 2019). In this context, several studies proposed mid-afternoon as the best time to onset nap (Waterhouse et al., 2007;Romdhani et al., 2021;Souabni et al., 2021). In the same way, all the studies included in the present systematic review initiated the NAPO in the mid-afternoon between 13:00 and 14:00 h. ...
... Three studies (Campbell et al., 2005;Baran et al., 2016;Fitzroy et al., 2021) reported a duration of 120 min for NAPOs and the remaining studies (n = 3) reported NAPOs with lower durations [i.e., 20 (Milner and Cote, 2008), 30 (Tamaki et al., 1999(Tamaki et al., , 2000 and 60 min (Milner and Cote, 2008)]. In addition, in a recent systematic review by our team, we suggested 90 min as an optimal NAPO for athletes undergoing chronic sleep deprivation (Souabni et al., 2021). The reason was twofold: for one, it is postulated that rapid eye movement (REM) sleep has a vital role in restorative benefits for cognition (Belenky et al., 2003;Hobson, 2005) and is also associated with memory consolidation and learning of motor skills (Davenne, 2009;Venter, 2012), while non-rapid eye movement (NREM) sleep is when the body actively repairs and restores itself (Davenne, 2009;Venter, 2012). ...
Article
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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.
... Although relations between movement behaviors and sleep in early childhood have been inconsistent, studies have been limited and most have solely examined overnight sleep-often not taking daytime sleep into account in analyses [12,13]. It is possible that napping could contribute to increased feelings of energy and motivation for movement, and high levels of movement could in turn improve the quantity and quality of nap sleep [14]. Among the few observational studies that have reported associations between nap sleep measures and movement behaviors in toddlers or preschool-aged children, findings have been generally null [15][16][17] or mixed [18]. ...
... Studies in adults have highlighted some aspects relating to movement and performance that are benefitted by daytime napping. For example, among physically active adults, recovery and performance metrics of activity (e.g., power, reaction time, and endurance) appear to benefit from a daily nap [14]. These pathways have yet to be fully explored, but could potentially exist in young children. ...
Article
Full-text available
The purpose of this micro-longitudinal study was to explore daily associations between daytime movement behaviors (sedentary time and physical activity) and nap sleep in young children. In 298 children (age = 51.0 ± 9.6 months, 43.6% female), wrist-based actigraphy (mean wear time = 10 days) assessed sedentary time, total physical activity, and provided an estimate of nap sleep duration and efficiency. Multilevel logistic and linear regression models were used to examine temporal within-person relations between wake behaviors and nap sleep, and adjusted for overnight sleep duration between days of interest, age, sex, and socioeconomic status. Movement behaviors were not related to the likelihood of next-day napping, but when children were less sedentary (OR = 0.96; p < 0.001) or more active (OR = 1.01; p = 0.001) in the morning, they were more likely to nap that same day. Movement behaviors were not associated with nap sleep duration or efficiency. Conversely, on days children napped, they were less sedentary (B = −2.09, p < 0.001) and more active (B = 25.8, p < 0.001) the following day. Though napping and movement behaviors had some reciprocal relations, effect sizes in the present study were small. Further studies should examine children with more diverse sleep health and from different childcare settings.
... Results showed no significant difference between combinations of night-time sleep and daytime naps in TST (i.e., measured via polysomnography), providing evidence that napping may be an effective strategy to achieve an optimal sleep duration and counteract the effect of sleep deprivation on physical performance in athletes. Napping is a safe and non-invasive intervention that is simple to introduce into athletes' schedules (Souabni et al., 2021). All indications suggest that diurnal napping improved maximal short-term (Daaloul et al., 2019;Waterhouse et al., 2007) and endurance (Keramidas et al., 2018) performance. ...
... This could explain the non-significant results in test sessions for SST. According to Souabni et al. (2021), the more exhaustive the task is, the more the need for a nap will be important. In the retest sessions, while HR mean increased significantly from ≈50% HR max (SST-test) to ≈80% HR max (SST-retest), the shooting percentage decreased significantly for both conditions. ...
Article
The effect of a 40-min nap opportunity on physiological responses and specific abilities was investigated. Twelve high-level professional basketball players (26.33±5.2 years; 193.17±7.1 m; 87.48±11.2 kg) undertook randomly 40-min nap opportunity (NAP) and control condition (CON). Wellness (Hooper Index) and Epworth Sleepiness Scale (ESS) were measured before and after both conditions. Defensive (DA) and offensive (OA) agility and upper body power (UBP) were assessed after both conditions. Shooting skill (SST) performance was evaluated prior and after a fatiguing task (FT). Heart rate (HR) and rating of perceived exertion (RPE) were recorded during SST-test, FT and SST-retest. ESS, Hooper's stress and fatigue score were significantly lower after nap compared to those before nap (0.009 ≤ p ≤ 0.03). Better performance was obtained in NAP compared to CON condition for DA, OA and UBP (0.0005 ≤ p ≤ 0.02). SST performance was significantly higher in NAP compared to CON in the retest session (p = 0.003, Δ = 20.2%). The improved performance was associated with significant lower HRpeak (p = 0.01, Δ = 5.25%) and RPE (p = 0.003, Δ = 15.12%). In conclusion, NAP reduced sleepiness and stress and fatigue and enhances physical outcomes of specific skills in elite basketball players.
... In addition, the participants in these studies were athletes. It could also be considered that a longer napping duration is better for athletes because they must recover from training to improve their performance in sports through sleep [33]. However, these points are the main differences between previous studies and the present study. ...
Article
Full-text available
Reportedly, daytime napping affects the physical fitness of athletes. However, results of these studies are conflicting, and may not be generalizable to all populations. Early adulthood is an important period linking adolescents and adults, during which building good physical fitness is crucial for their remaining lives. Thus, we investigated whether daytime napping duration is associated with physical fitness among Chinese university students. This study was based on an annual physical health examination for all university students and included 11,199 participants (6690 males; 4509 females). The daytime napping duration was assessed using a self-report questionnaire. Physical fitness was measured with a 50 m sprint; 1000 m (for males) and 800 m (for females) runs; standing long jump, sit-and-reach, pull-up (for males), and sit-up (for females) tests; and vital capacity. The adjusted association was evaluated using analysis of covariance. Of the participants, 86% napped regularly. After covariate adjustment was performed, significant V-shaped associations were observed between the daytime napping duration and the 50 m sprint and 800 m run results in males and females. Inverted V-shaped associations were observed between the daytime napping duration and the sit-and-reach, standing long jump, and pull-up test performances and vital capacity in males and between the daytime napping duration and the standing long jump test performance in females. Daytime napping for <30 min may have beneficial effects on physical fitness among university students.
... Overall, despite the detrimental effect of TSD on an individual's cognitive functions, ingesting repeated low doses of caffeine appears to improve them at rest as well as during exhaustive endurance exercise, which may help delay fatigue and improve physical performance. In the same context, it is important to emphasize that other recent studies (Romdhani et al. , 2020Souabni et al. 2021) propose the strategy of napping as a very effective means that could mitigate physical and cognitive impairments induced by sleep loss. ...
Article
The present study aimed to assess the effects of repeated administration of low-dose caffeine during a night of total sleep deprivation on physical and cognitive performance. Twelve recreational runners (being non-habitual caffeine users) performed four test sessions in a double-blind randomized order after (i) a placebo or 6 mg/kg of caffeine ingestion during a baseline night (BN) or (ii) a placebo or three doses of 2 mg/kg of caffeine during a night of total sleep deprivation (TSD). At each session, they completed an exhaustive run at 75% of the final velocity in a Vameval test (Vvameval) around a 400 m outdoor athletics track and performed the correct detection and reaction time tasks. In comparison with BN, the TSD condition significantly impaired running performance, reaction time, and correct detections. On the contrary, caffeine intake improved exhaustive running performance after BN by 5.2% (p < .001) and after TSD by 8.9% (p < .001), increased correct detections after BN (p < .05) and TSD (p < .05), and decreased reaction time after BN (p < .01) and TSD (p < .05) compared to placebo. Therefore, the repeated ingestion of low-dose caffeine is an effective strategy to counteract the detrimental effects of total sleep deprivation on physical and cognitive performance.
... Recuperative naps could be a replacement for lost sleep, prophylactic naps are used ahead of an expected sleep loss, and appetitive naps are just for the joy of napping (21). Short recuperative and appetitive naps could be beneficial for physical and cognitive performance (22)(23)(24)(25)(26). Long recuperative daytime naps (27), but not long appetitive naps (28), could also be beneficial for physical and cognitive performances. ...
Article
Full-text available
Objective: Disrupted sleep and training behaviors in athletes have been reported during the COVID-19 pandemic. We aimed at investigating the combined effects of Ramadan observance and COVID-19 related lockdown in Muslim athletes. Methods: From an international sample of athletes (n = 3,911), 1,681 Muslim athletes (from 44 countries; 25.1 ± 8.7 years, 38% females, 41% elite, 51% team sport athletes) answered a retrospective, cross-sectional questionnaire relating to their behavioral habits pre- and during- COVID-19 lockdown, including: (i) Pittsburgh sleep quality index (PSQI); (ii) insomnia severity index (ISI); (iii) bespoke questions about training, napping, and eating behaviors, and (iv) questions related to training and sleep behaviors during-lockdown and Ramadan compared to lockdown outside of Ramadan. The survey was disseminated predominately through social media, opening 8 July and closing 30 September 2020. Results: The lockdown reduced sleep quality and increased insomnia severity (both p < 0.001). Compared to non-Muslim (n = 2,230), Muslim athletes reported higher PSQI and ISI scores during-lockdown (both p < 0.001), but not pre-lockdown (p > 0.05). Muslim athletes reported longer (p < 0.001; d = 0.29) and later (p < 0.001; d = 0.14) daytime naps, and an increase in late-night meals (p < 0.001; d = 0.49) during- compared to pre-lockdown, associated with lower sleep quality (all p < 0.001). Both sleep quality (χ2 = 222.6; p < 0.001) and training volume (χ2 = 342.4; p < 0.001) were lower during-lockdown and Ramadan compared to lockdown outside of Ramadan in the Muslims athletes. Conclusion: Muslim athletes reported lower sleep quality and higher insomnia severity during- compared to pre-lockdown, and this was exacerbated by Ramadan observance. Therefore, further attention to Muslim athletes is warranted when a circadian disrupter (e.g., lockdown) occurs during Ramadan.
... Many people have a habit of diurnal napping, which is widely recommended as a safe and non-invasive intervention to counteract the negative effects of partial sleep deprivation. Souabni et al. reported that diurnal napping improves short-term memory, attention, reaction time, repeated-sprint, endurance, and specific skill performance, with greater improvement following longer naps [10]. However, a long napping duration may be detrimental to one's health. ...
Article
Full-text available
Background A lack of sleep or disorder in sleep–wake cycles has been associated with metabolic impairments. However, few studies have investigated the association between daytime napping duration and the risk of non-alcoholic fatty liver disease. This study aimed to investigate the association of daytime napping duration with the risk of non-alcoholic fatty liver disease in a Chinese population. Methods This cross-sectional study analyzed data from the Health Management Center of Nanfang Hospital, Guangdong Province. A total of 3363 participants aged 20–79 years were recruited and admitted from January 20, 2018, to October 16, 2020. Non-alcoholic fatty liver disease was diagnosed using abdominal ultrasonography. The outcome was the association between daytime sleep duration and the risk of non-alcoholic fatty liver disease. Results Compared with non-nappers, long daytime nappers (≥ 60 min) were associated with a higher risk of non-alcoholic fatty liver disease in the crude model (odds ratio 2.138; 95% confidence interval 1.88–2.61, P < 0.05) and in the multivariable adjustment model (odds ratio 2.211; 95% confidence interval 1.042–4.690, P < 0.05) after adjusting for demographic, educational, and metabolic risk factors. The association was moderately enhanced with additional adjustments for night sleep duration and socioeconomic or other factors (odds ratio 2.253; 95% confidence interval 1.061–4.786, P = 0.035). Conclusion In this cross-sectional study, daytime napping duration of ≥ 60 min was positively associated with the risk of non-alcoholic fatty liver disease in an occupational population of Guangdong Province after multivariable adjustment.
... However, the post hoc power analysis showed a statistical power of 63%. Fifth, diurnal naps are regarded as an advantageous intervention to enhance the recovery process and mitigate the negative effect of partial sleep deprivation on physical and cognitive performance (Lastella et al., 2021;Souabni et al., 2021). In the present study, although nap records were found in several players' sleep diaries, they were not habitual, so it was difficult for us to make further analyses on naps. ...
Article
Full-text available
We evaluated the relationships of daily sleep duration and inconsistency with soft tennis competitive performance among 15 healthy collegiate soft tennis players (13 male, 2 female, mean age = 19.7 ± 0.8 years, height = 170.8 ± 7.3 cm, weight = 60.3 ± 5.6 kg, soft tennis experience = 8.7 ± 2.0 years). Sleep duration and inconsistency were determined by a 50-day sleep diary, which recorded sleep and wake times of sleep. Soft tennis athletic performance was evaluated by a service and baseline stroke accuracy test and the spider run test. Mean sleep duration was 7.4 ± 1.7 h. No correlation was found between long-term mean sleep duration and athletic performance. But inconsistency in sleep duration (SD of sleep duration) was inversely correlated with service score after controlling for soft tennis experience and sex ( r = −0.56, p = 0.046). There was no significant relationship between sleep inconsistency and other athletic performance. This result indicates that reducing the instability of sleep duration (i.e., sleep regular hours) in the long-term may have a positive effect on soft tennis players’ service performance. Although participants’ current mean sleep duration (7.4 h) was not as sufficient as the recommendation in sleep extension experiments (9–10 h), it revealed the importance for athletes to maintain regular sleep in daily life.
... However, the post hoc power analysis showed a statistical power of 63%. Fifth, diurnal naps are regarded as an advantageous intervention to enhance the recovery process and mitigate the negative effect of partial sleep deprivation on physical and cognitive performance (Lastella et al., 2021;Souabni et al., 2021). In the present study, although nap records were found in several players' sleep diaries, they were not habitual, so it was difficult for us to make further analyses on naps. ...
Article
Full-text available
We evaluated the relationships of daily sleep duration and inconsistency with soft tennis competitive performance among 15 healthy collegiate soft tennis players (13 male, 2 female, mean age = 19.7 ± 0.8 years, height = 170.8 ± 7.3 cm, weight = 60.3 ± 5.6 kg, soft tennis experience = 8.7 ± 2.0 years). Sleep duration and inconsistency were determined by a 50-day sleep diary, which recorded sleep and wake times of sleep. Soft tennis athletic performance was evaluated by a service and baseline stroke accuracy test and the spider run test. Mean sleep duration was 7.4 ± 1.7 h. No correlation was found between long-term mean sleep duration and athletic performance. But inconsistency in sleep duration (SD of sleep duration) was inversely correlated with service score after controlling for soft tennis experience and sex (r = −0.56, p = 0.046). There was no significant relationship between sleep inconsistency and other athletic performance. This result indicates that reducing the instability of sleep duration (i.e., sleep regular hours) in the long-term may have a positive effect on soft tennis players’ service performance. Although participants’ current mean sleep duration (7.4 h) was not as sufficient as the recommendation in sleep extension experiments (9–10 h), it revealed the importance for athletes to maintain regular sleep in daily life.
... The cognitive recovery using a-tDCS of some fundamental cerebral functions like attention, visuoperception, response time and working memory in healthy young health workers, are like the effects induced by diurnal napping in healthy athletes 29 . However, in fatigued and sleep-deprived health workers the potential benefits of this neuromodulatory intervention not only include the personal benefit of decrease fatal car accidents, as well decreasing the number of medical errors in hospitals to reduce morbidity and mortality 30 . ...
Article
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Background: Medical residents must sustain acute sleep deprivation, which can lead to nonfatal and fatal consequences in hospitals due to cognitive decline. Anodal transcranial direct current stimulation (a-tDCS) is a safe noninvasive neuromodulation technique that can induce depolarization of neurons. Previous studies in pilots have shown benefits against fatigue increasing wakefulness and cognitive performance. However, the effects of a-tDCS on cognition in acute sleep deprived healthcare workers remains unknown. Purpose: To evaluate cognitive changes in sleep deprived medical residents after one session of a-tDCS. Methods: Open clinical test-re-test study including 13 medical residents with acute sleep deprivation. Subjects received 1 session of bifrontal a-tDCS (2mAx20min), anodal over the left dorsolateral prefrontal region. Pre-and-post treatment subjects were tested with Beck anxiety inventory, Beck depression and HVLT tests, Rey´s and Taylor´s figures, Trail Making A/B, Stroop, Aleatory Digit retention test (WAIS), Digits and symbols and MoCA tests. Post-intervention was added the Executive functions and Frontal Lobes Neuropsychological Battery (BANFE2) test and changing the Taylor figure for Reyfigure. Results: Twelve medical residents were analyzed; 8 men and 4 women, 29.5 (+/-2.2) years mean age. All had a mean of 21.6 (+/-1.3) hours of sleep deprivation. There were no serious adverse events. We found statistically significant difference in Rey´s/Taylor´s figures (p=0.002), Trail Making Test (p=0.005), WAIS IV symbols (p=0.003), Word Stroop (p=0.021). BANFE-2 showed that the main affected area was the orbito-medial prefrontal region. Conclusion: a-tDCS appears safe and improves working memory, attention, response time and distractors elimination in acute sleep deprived medical residents.
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Although napping is commonly used as a strategy to improve numerous physical and cognitive performances, the efficacy of this strategy for improving postural balance has not yet been elucidated. Thus, the aim of this study was to conduct a comprehensive examination of the effect of a 60min nap opportunity (N60) on different components of postural control. Ten highly active individuals (age= 27±3.5 y, height= 1.75±0.52 m, weight= 66.02 ± 8.63kg) performed, in a randomized order, two afternoon test sessions following no nap (NN) and N60. Postural balance was assessed using the sensory organisation test (SOT), the unilateral stance test (UST), and the limits of Stability Test performed on NeuroCom® Smart Balance Master. The subjective rating of sleepiness before and after the nap conditions was also assessed. Compared to NN, N60 improved the composite balance score (p<0.05, ES = 0.75, Δ=5.3%) and the average and maximum percentage balance in the most challenging postural conditions of the SOT (p<0.05 for SOT-4 and 5 and p<0.0005 for SOT-6; ES range between 0.58 and 1.1). This enhanced postural balance in N60 was accompanied with improved visual (p<0.05; ES=0.93; Δ=8.9%) and vestibular (p<0.05; ES=0.81; Δ = 10.5%) ratios and a reduced level of sleepiness perception (p < 0.001, ES=0.87). However, no significant differences were found in any of the UST and LOS components’ scores (p>0.05). Overall, a 60 min post lunch nap opportunity may be viable for improving static balance, although further work, involving larger samples and more complex motor activities, is warranted.
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ABSTRACT Elite athletes are particularly susceptible to sleep inadequacies, characterised by habitual short sleep (<7 hours/night) and poor sleep quality (eg, sleep fragmentation). Athletic performance is reduced by a night or more without sleep, but the influence on performance of partial sleep restriction over 1–3 nights, a more real-world scenario, remains unclear. Studies investigating sleep in athletes often suffer from inadequate experimental control, a lack of females and questions concerning the validity of the chosen sleep assessment tools. Research only scratches the surface on how sleep influences athlete health. Studies in the wider population show that habitually sleeping <7 hours/night increases susceptibility to respiratory infection. Fortunately, much is known about the salient risk factors for sleep inadequacy in athletes, enabling targeted interventions. For example, athlete sleep is influenced by sport-specific factors (relating to training, travel and competition) and non-sport factors (eg, female gender, stress and anxiety). This expert consensus culminates with a sleep toolbox for practitioners (eg, covering sleep education and screening) to mitigate these risk factors and optimise athlete sleep. A one-size-fits-all approach to athlete sleep recommendations (eg, 7–9 hours/night) is unlikely ideal for health and performance. We recommend an individualised approach that should consider the athlete’s perceived sleep needs. Research is needed into the benefits of napping and sleep extension (eg, banking sleep).
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This study examined the effects of different nap durations on attention and physical performance as well as mood states, sleepiness, perceived exertion (RPE), recovery (PRS), and muscle soreness (DOMS) in trained men. Fourteen amateur team sport players (age: 20.3 ± 3.0 years, height: 173.1 ± 6.7 cm, body-mass: 68.1 ± 6.6 kg) performed a maximal voluntary isometric contraction (MVIC) test, 5-m shuttle run, and the digit-cancellation (i.e., attention) test after a no-nap (N0) and 40-min (N40) and 90-min (N90) of nap opportunities. Subjective measurement of mood states, RPE, PRS and DOMS were determined. Compared to N0, both nap durations enhanced attention, MVIC, total distance (TD), and higher distance (HD) (p < 0.001), with a higher gain after N90 compared to N40 for attention (Δ = +3), MVIC (Δ = +30N) and TD (Δ = +35m) (p < 0.001). Total mood scores were better after N40 and N90 compared to N0 (p < 0.05), with lower scores after N90 compared to N40 (p < 0.05). DOMS and RPE scores were significantly lower and PRS was significantly higher after N40 and N90 compared to N0 and after N90 compared to N40 (p < 0.05). Although both nap opportunity durations were beneficial, N90 was better than N40 for improving physical performances and attention as well as the perception of recovery, reducing fatigue perception, muscle soreness, and negative mood states.
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Purpose. To compare the effect of different durations of nap opportunity during the daytime on repeated high-intensity short-duration performance and rating of perceived exertion (RPE). Methods. Seventeen physically active men (age: 21.3±3.4 y, height: 176.7±5.9 cm, body mass: 71.8±10.2 kg) performed a 5 m shuttle run test (to determine best distance (BD), total distance (TD) and fatigue index (FI)) under four conditions: a 25 min nap opportunity (N25), a 35 min nap opportunity (N35), a 45 min nap opportunity (N45) and control (no-nap) (N0). The sleep quality of each nap opportunity was evaluated using a scale ranging from 0 “no sleep” to 10 “uninterrupted, deep sleep throughout”. The four conditions were performed in a random order. RPE was recorded after each repetition of the test and the mean score was calculated. Results. BD increased after N25 (+6%) and N45 (+9%) compared to N0 (p<0.05) and was significantly higher after N45 compared to N35 (p<0.05). Compared to N0, the three nap opportunity durations enhanced TD (p<0.05) with greater enhancement after N45 compared to N25 (+8% vs. +3%) and N35 (+8% vs. +3%). For FI, no-significant differences were observed between the three nap opportunity durations and N0. The mean RPE score was significantly higher after N25 (+20%) and N0 (+19%) compared to N45 (p<0.05). All participants were able to fall asleep during each nap condition with a sleep quality score of 6.9±1.0, 7.0±0.7 and 7.1±0.8 for N25, N35 and N45. Conclusion. A nap opportunity during the daytime was beneficial for physical performance and perceived exertion with the N45 being the most effective for improving performance and reducing fatigue during the 5 m shuttle run test. The implication of the present study is that athletes might benefit from a nap opportunity of 25, 35 or 45 min before practice or before a competition.
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Objective This study reviewed systematically the effects of sleep extension on sports performance. Design systematic review. Method The systematic review was conducted in November 2020. Articles published in English were searched in PubMed, Virtual Health Library, SPORTDiscus, and Web of Science and Scopus databases. The search terms used were “sleep extension” AND athlete. The measures of interest were sports performance. Studies were included if they were a) original articles, b) published in English and peer-reviewed article, c) had only athletes as participants, d) experimental protocol whose objective was to investigate the effects of sleep extension on sports performance, including randomized (RCT) and non-randomized controlled trial (nRCT), and e) at least a sports performance measure as a dependent variable. Results The primary search revealed that a total of 5 out of 74 articles were considered eligible and 2 studies were subsequently included. The studies used different strategies to extend time in bed or total sleep time (extending 26 to 106 min). From fifteen sports measures, six presented a large effect size, and the others ranged from trivial to medium. Overall, the risk of bias was high to RCT and low to nRCT and the quality of evidence ranged from very low quality to moderate quality in ten outcomes. Conclusions The limited evidence suggests that sleep extension interventions may be beneficial to improve sports performance in athletes where the magnitude is dependent on the variable assessed, although such conclusions are tentative because of the quality of the evidence and risk of bias.
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A growing body of research focus on athletes’ sleep in order to investigate the effects of sleep in sports performance and recovery or the prevalence of sleep disorders in athletes. At the same time, several sleep monitoring tools have been developed and used in athletic populations for fulfilling these purposes. This review aimed to provide critical assessment to the most used by athletes’ methodological approaches and compared them with the gold standard approach. Advantages and disadvantages of the various sleep monitoring tools were critically discussed. Literature related to aspects of athletes’ sleep was reviewed. From the shortlisted studies, several factors that seem to affect sleep in athletes were identified using objective methods such as polysomnography/electroencephalography and actigraphy. These factors were associated to sleep (e.g. such as sleep environment, familiarization procedures and napping) and daily habits (e.g. nutrition, fluid consumption, alcohol and caffeine intake, tobacco use). The selected studies that evaluated sleep objectively were screened according the reporting rates of these variables. The majority of the screened studies were found to underreport these variables. Practical issues were addressed and recommendations about reporting sleep-related factors were made in order to improve studies’ quality assessment and allow for more robust comparisons between studies.
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The aim of the present study was to determine the effect of different nap opportunity durations on short-term maximal performance, attention, feelings, muscle soreness, fatigue, stress and sleep. Twenty physically active men (age: 21.1±3.6 years, height: 176.4±5.7 cm, body-mass: 72±10.8 kg) performed the 5-jump and the digit-cancellation (i.e., attention) tests after four randomized nap opportunity conditions: no-nap opportunity (N0), 25 min of nap opportunity (N25), 35 min of nap opportunity (N35) and 45 min of nap opportunity (N45). Subjective measurement of feelings, muscle soreness, fatigue, stress and sleep were performed during each test session. Compared to N0, there was a significant improvement of the 5-jump performance during N35 (Δ=+3.5%, p<0.01) and N45 (Δ=+3.7%, p<0.01). Attention was also better after N45 compared to N0 (Δ=+7.5%, p<0.05). Fatigue, sleep and stress scores were significantly lower after N25, N35 and N45 compared to N0 (p<0.05). However, no-significant effect of naps durations on feelings and fatigue scores was observed. A nap opportunity has a beneficial effect on physical performance and attention with better results observed for naps ≥35 min.