The effect of sleep deprivation on choice reaction time and anaerobic power of college student athletes

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

Objective

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

Methods

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

Results

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

Conclusion

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

Living in urban or rural environments affect the sleep quality of the elderly in Bushehr (Southern Iran): emphasizing the active and inactive of the elderly

INTRODUCTION

Sleep disorders have a significant negative impact on mental and physical health, especially among the elderly. Various factors can affect the sleep quality of elderly people. The aim of this research to investigate the effect of urban and rural environments on the sleep quality of elderly people with emphasis on physical activity.

METHOD

Four hundred and thirty-nine elderly people (226 city residents and 213 village residents) in urban and rural areas of Bushehr (Southern Iran), volunteered to participate in the present study. Information was collected via the General information questionnaire and Petersburg Sleep Questionnaire.

RESULT

The results showed that active elderly women (p < 0.001), and total active elderly (male + female) (p < 0.001) living in urban areas compared to inactive elderly and also in rural areas active elderly women (p < 0.001), active elderly men (p < 0.001) and total active elderly (male + female) (p < 0.001) had better overall sleep quality in compared to inactive elderly. Also, elderly men (p < 0.001) and the total elderly (male + female) (p < 0.001) living in urban areas had better sleep quality than the elderly in rural areas.

CONCLUSION

Based on the findings, it can be concluded that the way of life (being active) as well as the living environment can affect the sleep quality of elderly people, so that active elderly people and also elderly people living in urban environments had better sleep quality.

The Impact of Knee and Ankle Injuries on National Basketball Association Player Performance Post-injury

INTRODUCTION

Athletes in the National Basketball Association (NBA) are subjected to high levels of mechanical stress increasing their risk of injury. The purpose of this study was to see how certain lower extremity injuries affect in-game performance in relation to each NBA athlete's demographics. The hypothesis was that NBA players' post-injury performance would differ depending on their demographics and the type of injury sustained.

METHODS

Descriptive epidemiology study of NBA injury list designations from the 2010/2011 season to the 2018/2019 season. About 255 lower leg injuries that met the inclusion criteria were selected from the injury lists spanning from the 2010/2011 season to the 2018/2019 season. These included ligamentous knee injuries, knee sprains, knee strains, knee hyperextensions, patellar injuries, ankle injuries, and Achilles injuries. The change in performance was determined by comparing mean game scores before and after injury with single-tailed, heteroscedastic t-testing and 95% confidence intervals for mean values.

RESULTS

An overall statistically significant decrease in mean game score from 9.82 to 8.75 was seen in all included players (p = 0.01). Only athletes taller than the mean height (199.85 cm; p = 0.01) and heavier than the mean weight (101.63 kg; p = 0.02) showed a significant decline in performance. Ankle and knee injuries both resulted in a significant loss in game score (p = 0.04), with ankle injuries resulting in a greater average decline (-1.76 post-injury) than knee injuries (-1.34 post-injury).

CONCLUSIONS

These findings suggest that treatment regimens should reflect the type of injury and demographics of the specific NBA player injured. Further research is warranted to determine if treatment may be more efficacious when streamlined based on player size and injury type.

The effects of sleep deprivation and extreme exertion on cognitive performance at the world-record breaking Suffolk Back Yard Ultra-marathon

Using a prospective observational design, this study investigated the hypothesis that competing in the Suffolk Back Yard Ultra-marathon, would result in impaired cognitive performance and examined whether pre-race sleep patterns could mitigate this. Fifteen runners (1 female) volunteered to undertake this study and eleven males were included in the final analysis. Before the race and after withdrawal participants completed the following cognitive performance tasks: 2 Choice Reaction Time (2CRT), Stroop, and the Tower Puzzle. Pre-race sleep strategies were subjectively recorded with a 7-day sleep diary. Following race withdrawal, reaction time increased (Δ 77±68 ms; p = 0.004) in the 2CRT and executive function was impaired in the Stroop task (Interference score Δ -4.3±5.6 a.u.; p = 0.028). Decision making was not affected in the Tower Puzzle task. There was a significant correlation between the pre-race 7-day average sleep scores and both 2CRT Δ throughput (r = 0.61; p = 0.045) and 2CRT Δ RT (r = -0.64; p = 0.034). This study supports the hypothesis that running an ultra-marathon, which includes at least one night of sleep deprivation, impairs cognitive performance and provides novel evidence suggesting good sleep quality, in the week prior to an ultra-marathon, could minimise these effects.

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

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

Assessing between-officer variability in responses to a live-acted deadly force encounter as a window to the effectiveness of training and experience

We aimed to infer the effectiveness of officers' training and experience by assessing consistency of behavioural responses between them. If officers facing the same scenario respond in similar ways, this implies their use of shared cognition, through acquired in-common tactical knowledge. Officers (n = 42) responded to a live-acted scenario in which an assailant ultimately discharged his weapon. Triangulated camera positions assessed their movement patterns, final positions, and weapon responses relative to when the assailant fired his weapon. We also assessed the officers' visual search and gathered information regarding their experience and rest. Our second aim was to examine sources of variability in the officers' responses. We found extensive variability in all aspects of the response. Experience did not impact spatial or temporal behavioural responses. However, longer hours awake and lower reported rest negatively impacted officers' responses. We conclude that officers had insufficient training and experience to demonstrate in-common knowledge.Practitioner summary: Police officers showed high spatial and temporal variability in response to the same scenario. This implies inadequate tactical training, and is supported by our finding that training and experience did not impact performance. Instead, the officers' variability was constrained by their visual search, and the hours awake before being tested.

Total sleep deprivation reduces the table tennis anticipation performance of young men: A functional magnetic resonance imaging study

This study explored whether and how sleep deprivation (SD) affects sport-related anticipation. Twenty table tennis players and 28 non-athletes completed a table tennis anticipation task before and after 36 h SD. Functional magnetic resonance imaging (fMRI) data were acquired simultaneously. The results showed that, compared with the non-athletes, table tennis players had higher neural efficiency, manifested by their higher anticipation accuracy and lower frontal lobe activation. SD impaired anticipation performance, accompanied by decreased activation of the occipital and temporal lobes. Compensatory activation occurred in the left hippocampus and orbital part of the right inferior frontal gyrus (IFG) after SD in the table tennis player group, but not in the non-athlete group. The decreased accuracy of non-athletes was positively correlated with decreased activation of orbital part of the right IFG. This study's findings improve the understanding of the cognitive neuroscience mechanisms by which SD affects sport-related anticipation.

Sleep restriction between consecutive days of exercise impairs sprint and endurance cycling performance

The study aim was to determine the effect of sleep restriction (3 h) between consecutive days of exercise on sprint and endurance cycling performance, wellness, and mood. A total of 10 well-trained males performed 2 consecutive-day trials separated by a normal night sleep (control [CONT]; mean [SD] sleep duration 3.0 [0.2] h) or sleep restriction (RES; mean [SD] sleep duration 3.0 [0.2] h). Experimental trials included a 90-min fixed-paced cycling bout and the respective sleep conditions on Day 1, followed by two 6-s peak power (6-s PP) tests, a 4- and 20-min time trial (TT) on Day 2. Profile of Mood States (POMS) and wellness questionnaires were recorded on Day 1 and Day 2. Blood lactate and glucose, heart rate (HR), and rating of perceived exertion were recorded throughout Day 2. Power output (PO) was significantly reduced for RES in the 6-s PP trial (mean [SD] 1159 [127] W for RES versus 1250 [186] W for CONT; p = 0.04) and mean PO during the 20-min TT (mean [SD] 237 [59] W for RES versus 255 [58] W for CONT; p = 0.03). There were no differences for HR, lactate and glucose, or POMS between CONT and RES in all experimental trials (p = 0.05-0.89). Participants reported a reduction in overall wellness prior to exercise on Day 2 following RES (mean [SD] 14.5 [1.6] au) compared to CONT (mean [SD] 16 [3.0] au; p = 0.034). Sleep restriction and the associated reductions in wellness, reduce cycling performance during consecutive days of exercise in a range of cycling tests that are relevant to both track and road cyclists.

Corrigendum: The relationships of sleep duration and inconsistency with the athletic performance of collegiate soft tennis players

[This corrects the article DOI: 10.3389/fpsyg.2022.791805.].

Prospective Implications of Insufficient Sleep for Athletes

CONTEXT

Poor sleep is common in collegiate student-athletes and is associated with heterogeneous self-reported complaints at baseline. However, the long-term implications of poor sleep at baseline have been less well studied.

OBJECTIVE

To examine the implications of insufficient sleep at baseline, as well as factors such as symptom reporting and neurocognitive performance at baseline associated with insufficient sleep, for the risk of sport-related concussion (SRC).

DESIGN

Cross-sectional study.

SETTING

Undergraduate institution.

PATIENTS OR OTHER PARTICIPANTS

Student-athletes (N = 614) were divided into 2 groups based on the hours slept the night before baseline testing: sufficient (>7.07 hours) or insufficient (≤5.78 hours) sleepers. Athletes who went on to sustain an SRC during their athletic careers at our university were identified.

MAIN OUTCOME MEASURE(S)

Four symptom clusters (cognitive, physical, affective, and sleep) and headache were examined as self-reported outcomes. Four neurocognitive outcome measures were explored: mean composite of memory, mean composite of attention/processing speed, memory intraindividual variability (IIV), and attention/processing speed IIV.

RESULTS

Insufficient sleepers at baseline were nearly twice as likely (15.69%) as sufficient sleepers (8.79%) to go on to sustain an SRC. Insufficient sleepers at baseline, whether or not they went on to sustain an SRC, reported a higher number of baseline symptoms than did sufficient sleepers. When compared with either insufficient sleepers at baseline who did not go on to incur an SRC or with sufficient sleepers who did go on to sustain an SRC, the insufficient sleep group that went on to incur an SRC performed worse at baseline on mean attention/processing speed.

CONCLUSIONS

The combination of insufficient sleep and worse attention/processing speed performance at baseline may increase the risk of sustaining a future SRC.

Examination of clinical sleep difficulties in college student-athletes

BACKGROUND

Due to the rising concern of inadequate sleep, critical analysis is needed for the presence of sleep problems in diverse populations. Research has shown that college athletes may be one such population at risk for sleep disturbances. Poor sleep may lead to physiological, psychological, and cognitive deficits that can impact college athletes academically and athletically. This investigation was performed to examine the relationship of age, sex, and history of concussion on sleep disturbance in college athletes.

METHODS

A total of 191 collegiate athletes between the ages of 18-26 from a single academic NCAA institution in the Rocky Mountain region of the USA, consented to participate in the study. Participants completed a demographic questionnaire and the Athlete Sleep Screening Questionnaire (ASSQ). Results were analyzed using SPSS Version 27.

RESULTS

Primary results revealed that female athletes reported higher sleep disturbance scores when compared to males (U=3643.0, P=0.016). Self-reported sleep disturbances when traveling for sport were higher for females (<inf>X</inf>(1) = 23.800, P<0.001). Males were also less likely to report daytime dysfunction when traveling for sport (<inf>X</inf>(1) =22.988, P<0.001). Sleep disturbance had a significant association with age (<inf>X</inf>(1) =4.145, P=0.042), with older participants (20+ years of age) reporting greater sleep disturbance. Concussion history did not associate with sleep disturbance in the present study.

CONCLUSIONS

Results suggest that sophomore or older female may be at higher risk for sleep disturbances. Clarifying sex-specific sleep health and understanding the role of age and academic class is crucial to enhance and personalize interventions.

Functional Outcomes, Injury Variables, and Athlete Characteristics Associated with Post-Concussion Sleep Disturbance

OBJECTIVE

To examine the relationship between sleep disturbance and functional outcomes following a concussion. Also, to explore athlete and injury-related variables that may be related to risk factors for poor sleep following concussion.

METHOD

124 collegiate athletes completed a neuropsychological evaluation within 14 days of sustaining a sport-related concussion (SRC). Athletes were categorized as sleep disturbed (n = 52) or not sleep disturbed (n = 72). Outcome variables included symptom reports, cognitive performance (mean performance and variability), and mood (depression). Injury characteristics and athlete characteristics explored were loss of consciousness (LOC) associated with the injury, whether the athlete was immediately removed from play, and history of prior concussions.

RESULTS

Sleep disturbed athletes reported more symptoms, F(4, 119) = 7.82, p < 0.001, ƞ2 = 0.21, were more likely to be symptomatic at the time of testing, χ2(1, N = 124) = 19.79, p < 0.001, φ = 0.40, and were marginally more likely to experience clinically significant depression, χ2(1, N = 120) = 3.03, p = 0.08, φ = 0.16, than not sleep disturbed athletes. There were no cognitive differences between the groups, p > 0.05. A greater proportion of sleep disturbed athletes experienced LOC (30%) compared to not sleep disturbed athletes (13%), χ2(1, N = 118) = 4.99, p = 0.03, φ = -0.21.

CONCLUSION

Sleep disturbances following SRC are associated with a broad range of self-reported symptoms. LOC may be associated with an increased risk of developing sleep disturbances; alternatively, sleep disturbances may increase the risk of LOC following concussion.

Impact of COVID-19 pandemic on cross-country runners: changes in training, sleep, diet, and mental health

Objective: Determine the impact of the COVID-19 pandemic on the changes in training, sleep, diet, and mental health of cross-country runners. Participants: Cross-country runners from NCAA Division II institutes. Methods: Wilcoxon signed-rank test was performed to analyze survey responses to ordinal questions on the survey while Spearman's rank correlation analysis (ρ) was used to calculate correlation between after the start of pandemic questions. Data was marked significant at p < 0.05. Results: Analysis of the survey responses revealed that cross-country runners were more likely to experience feelings of depression (p < 0.001), lack of motivation (p < 0.001), and higher daily stress (p < 0.001) after the start of the pandemic. After the start of the pandemic, runners running less days per week were more likely to report an increased feeling of depression (ρ=-0.315, p = 0.008) and lack of motivation (ρ=-0.458, p < 0.001). Conclusions: The present study underscores the importance of training, sleep, diet, and mental health amongst cross-country runners.

Indirect effect of mindfulness on psychological distress via sleep hygiene in division I college student athletes

ObjectiveThe unique demands placed on Division I student athletes (SAs) puts them at risk of experiencing poor sleep and increased psychological distress. Researchers have found that mindfulness improves well-being, directly and indirectly via sleep behaviors; however, it is not known if these relationships hold up within a sample of SAs. Thus, this study examined the indirect effect of mindfulness on psychological distress through sleep hygiene in SAs. Participants and methods: A sample of 269 Division I SAs were surveyed on their psychological distress, sleep hygiene, and mindfulness in 2018-2019. Results: Mindfulness directly and indirectly influenced psychological distress via sleep hygiene (B = -0.03, SE = 0.01, 95% CI [-0.05, -0.01]) such that increased mindfulness was associated with improved sleep hygiene and reduced distress. Conclusions: The results show the impact of mindfulness on sleep hygiene and psychological distress. Training SAs in mindfulness might improve sleep behaviors and in turn well-being.

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

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

Sleep and 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.

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

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

Acute Sleep Deprivation Impairs Motor Inhibition in Table Tennis Athletes: An ERP Study

Excellent response inhibition is the basis for outstanding competitive athletic performance, and sleep may be an important factor affecting athletes’ response inhibition. This study investigates the effect of sleep deprivation on athletes’ response inhibition, and its differentiating effect on non-athlete controls’ performance, with the aim of helping athletes effectively improve their response inhibition ability through sleep pattern manipulation. Behavioral and event-related potential (ERP) data were collected from 36 participants (16 table tennis athletes and 20 general college students) after 36 h of sleep deprivation using ERP techniques and a stop-signal task. Sleep deprivation’s different effects on response inhibition in the two groups were explored through repeated-measures ANOVA. Behavioral data showed that in a baseline state, stop-signal response time was significantly faster in table tennis athletes than in non-athlete controls, and appeared significantly longer after sleep deprivation in both groups. ERP results showed that at baseline state, N2, ERN, and P3 amplitudes were lower in table tennis athletes than in non-athlete controls, and corresponding significant decreases were observed in non-athlete controls after 36 h of sleep deprivation. Table tennis athletes showed a decrease in P3 amplitude and no significant difference in N2 and ERN amplitudes, after 36 h of sleep deprivation compared to the baseline state. Compared to non-athlete controls, table tennis athletes had better response inhibition, and the adverse effects of sleep deprivation on response inhibition occurred mainly in the later top-down motor inhibition process rather than in earlier automated conflict detection and monitoring.

The Relationships of Sleep Duration and Inconsistency With the Athletic Performance of Collegiate Soft Tennis Players

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 Impact of Early Morning Training Sessions on Total Sleep Time in Collegiate Athletes

Early morning training sessions may affect sleep quantity in athletes. The purpose of this study is to examine differences in total sleep time of collegiate athletes on nights prior to early morning training sessions relative to non-training nights. Wristwatch monitors equipped with photoplethysmography and accelerometer technology were worn by 18 NCAA Division III collegiate athletes (Age: 20.1 ± 1.6 years, Height: 1.81 ± 0.02 m, Body Mass: 91.2 ± 6.5 kg, Body Fat %: 20.8 ± 1.6%) during a two-week period of training to monitor total sleep times. Athletes recorded time in and out of bed using a sleep diary, anxiety levels due to having to wake up in the morning, and perceived recovery status (PRS) upon waking the next day. The data were divided into: nights before non-training days (NT) and Training days (TD). Data were analyzed using univariate analysis. All athletes obtained significantly less total sleep on nights before TD relative to NT (NT: 8:15 ± 1:03 vs. TD: 6:08 ± 0:59 hh:mm; p < 0.05). There was a positive relationship between total sleep time and recovery status (p < 0.01). Anxiety scores were inversely related to total sleep time (p < 0.01). Next-day recovery status was inversely related to anxiety scores (p < 0.001). College athletes obtained significantly less total sleep time on nights before early morning training sessions (< 0700) during the off-season, regardless of sex and sport. Coaches should consider later training sessions or promote optimal sleep quantity in order to minimize the risks associated to early morning training sessions.

Effects of Acute Sleep Loss on Physical Performance: A Systematic and Meta-Analytical Review

BACKGROUND

Sleep loss may influence subsequent physical performance. Quantifying the impact of sleep loss on physical performance is critical for individuals involved in athletic pursuits.

DESIGN

Systematic review and meta-analysis.

SEARCH AND INCLUSION

Studies were identified via the Web of Science, Scopus, and PsycINFO online databases. Investigations measuring exercise performance under 'control' (i.e., normal sleep, > 6 h in any 24 h period) and 'intervention' (i.e., sleep loss, ≤ 6 h sleep in any 24 h period) conditions were included. Performance tasks were classified into different exercise categories (anaerobic power, speed/power endurance, high-intensity interval exercise (HIIE), strength, endurance, strength-endurance, and skill). Multi-level random-effects meta-analyses and meta-regression analyses were conducted, including subgroup analyses to explore the influence of sleep-loss protocol (e.g., deprivation, restriction, early [delayed sleep onset] and late restriction [earlier than normal waking]), time of day the exercise task was performed (AM vs. PM) and body limb strength (upper vs. lower body).

RESULTS

Overall, 227 outcome measures (anaerobic power: n = 58; speed/power endurance: n = 32; HIIE: n = 27; strength: n = 66; endurance: n = 22; strength-endurance: n = 9; skill: n = 13) derived from 69 publications were included. Results indicated a negative impact of sleep loss on the percentage change (%_Δ) in exercise performance (n = 959 [89%] male; mean %_Δ =  - 7.56%, 95% CI - 11.9 to - 3.13, p = 0.001, I² = 98.1%). Effects were significant for all exercise categories. Subgroup analyses indicated that the pattern of sleep loss (i.e., deprivation, early and late restriction) preceding exercise is an important factor, with consistent negative effects only observed with deprivation and late-restriction protocols. A significant positive relationship was observed between time awake prior to the exercise task and %_Δ in performance for both deprivation and late-restriction protocols (~ 0.4% decrease for every hour awake prior to exercise). The negative effects of sleep loss on different exercise tasks performed in the PM were consistent, while tasks performed in the AM were largely unaffected.

CONCLUSIONS

Sleep loss appears to have a negative impact on exercise performance. If sleep loss is anticipated and unavoidable, individuals should avoid situations that lead to experiencing deprivation or late restriction, and prioritise morning exercise in an effort to maintain performance.

The influence of shift work on the psychomotor capabilities of emergency medicine residents

OBJECTIVE

Shift work affects health status of healthcare providers and patients. We assessed the effect of shift work on psychomotor activities of emergency medicine residents of 3 university hospitals.

METHODS

The participants were enrolled to perform selected psychomotor tests via the Vienna test system (VTS) after written consent. They passed 4 episodes of test performance before and after 2 consecutive day and night clinical shifts of 12 hours. The status of general health, circadian rhythm, sleepiness, smoking habits, and the scores of the cognition test (COG), the determination test (DT), and the visual pursuit test of emergency medicine residents were compared before and after morning and night shifts.

RESULTS

Overall, 23 residents (34.8% were male) performed tests. The mean (SD) age was 35.7 + 8.5 years. The mean general health and circadian scores before and after day/night shifts were not different. The Stanford sleepiness scale showed higher scores after night shifts. In the cognition test, the sum of correct rejections was higher after day shifts. Moreover, in the DT results, correct responses were more prevalent, the omitted responses were fewer accompanied by better median reaction time after day shifts. The sum of correct rejections of the COG test showed difference in terms of improved results in night tests compared to day-shift tests. The mean reaction time of the DT showed significant difference with shorter reaction time in night-shift tests. The visual pursuit test results were not different between day and night shifts.

CONCLUSIONS

Sleepiness was higher after night shifts. The results of selected psychomotor tests showed that the psychomotor function of the residents was not delayed or worse after night shifts in comparison to the day shifts.

Sleep Duration Correlates With Performance in Ultra-Endurance Triathlon

The relationship between sleep duration, sleep quality, and race completion time during each stage of a 3-day ultra-endurance triathlon (stage 1: 10-km swim, 146-km cycle; stage 2: 276-km cycle; and stage 3: 84.4-km run) was investigated. Seventeen triathletes partook in sleep analysis throughout the ultra-endurance multiday triathlon using an actigraphy wristband. The participants wore the band to record objective sleep outcomes for approximately 4 days (1-2 d prerace, 3 race days, and 1 d postrace), except while racing. The total sleep time (TST; prerace: 414.1 [95.3] min, prestage 1: 392.2 [138.3] min, prestage 2: 355.6 [62.5] min, and prestage 3: 299.7 [107.0] min) significantly decreased over time (P < .05). Significant Pearson moment-product correlations were found between TST and subsequent race-day performance for race stage 1 (r = -.577; P = .019) and stage 3 (r = -.546; P = .035), with further analysis revealing that TST explained 33% and 30% of the variation in performance for stages 1 and 3, respectively. During a 3-day ultra-endurance triathlon, the TST was reduced and had a significant negative correlation to exercise performance, indicating that sleep loss was associated with slower performances. Sleep onset latency, wake episodes, and sleep efficiency did not significantly change over the course of this investigation, which may stem from the close proximity of exercise to sleep.

The Effect of Sleep Quality and Quantity on Athlete's Health and Perceived Training Quality

University athletes are unique because they not only have to cope with the normal psycho-physiological stress of training and playing sport, but they also need to accommodate the stress associated with their academic studies along with considerable stress from their social environment. The ability to manage and adapt to stress ultimately helps improve athletic performance, but when stress becomes too much for the athlete, it can result in maladaptation's including sleep disruption which is associated with performance loss, negative mood changes, and even injury or illness. This research aimed to determine if sleep quantity and quality were associated with maladaptation in university athletes. We examined subjective measures of sleep duration and sleep quality along with measures of mood state, energy levels, academic stress, training quality and quantity, and frequency of illness and injury in 82 young (18–23 years) elite athletes over a 1 year period in 2020. Results indicate sleep duration and quality decreased in the first few weeks of the academic year which coincided with increased training, academic and social stress. Regression analysis indicated increased levels of perceived mood (1.3, 1.1–1.5, Odds Ratio and 95% confidence limits), sleep quality (2.9, 2.5–3.3), energy levels (1.2, 1.0–1.4), training quality (1.3, 1.1–1.5), and improved academic stress (1.1, 1.0–1.3) were associated with ≥8 h sleep. Athletes that slept ≥8 h or had higher sleep quality levels were less likely to suffer injury/illness (0.8, 0.7–0.9, and 0.6, 0.5–0.7 for sleep duration and quality, respectively). In conclusion, university athletes who maintain good sleep habits (sleep duration ≥8 h/night and high sleep quality scores) are less likely to suffer problems associated with elevated stress levels. Educating athletes, coaches, and trainers of the signs and symptoms of excessive stress (including sleep deprivation) may help reduce maladaptation and improve athlete's outcomes.

Ramadan Observance Is Associated with Impaired Kung-Fu-Specific Decision-Making Skills

The aim of the present study is to evaluate the effect of Ramadan observance (RAM) on decision-making in Kung-Fu athletes. Fourteen male Kung-Fu athletes (mean age = 19 ± 3 years) completed two test sessions: before Ramadan (BR) and at the end of Ramadan (ER). In the afternoon of each session (between 16:00 h and 18:00 h), participants completed: Epworth Sleepiness Scale (ESS), Profile of Mood States (POMS), and Pittsburg Sleep Quality Index (PSQI). Subjects also reported subjective fatigue, alertness, and concentration. Additionally, all participants performed video-based decision-making tasks (i.e., reaction time and decision-making). Results indicated that reaction time decreased by 30% at ER vs. BR (p < 0.01). However, decision-making decreased by 9.5% at ER vs. BR (p < 0.05). PSQI results indicated sleep quality score, sleep duration, and sleep efficiency were negatively affected at ER compared to BR (p < 0.05). ESS was higher at ER compared to BR (p < 0.05). In addition, fatigue scores, estimated by the POMS and current subjective feelings (i.e., fatigue, concentration, and alertness), were also negatively affected at ER compared to BR (p < 0.05). In conclusion, Ramadan observance was associated with an adverse effect on sleep and decision making, as well as feelings of fatigue, alertness, and concentration.

Hypnotic Effect of A. absinthium Hydroalcoholic Extract in Pentobarbital-Treated Mice

BACKGROUND

Current drugs used in the management of insomnia are associated with side effects. The use of medicinal herbs for insomnia treatment has recently been suggested.

OBJECTIVE

The present study aimed to determine the hypnotic activity of the hydroalcoholic extract of Artemisia absinthium (A. absinthium) in mice.

METHOD

The toxicity of A. absinthium extract is assessed by their lethal dose 50% (LD50), and cytotoxicity evaluation was also done with PC12 cell lines by MTT assay. A. absinthium extract (25, 50, 100, and 200 mg/kg) and 3 fractions (n-butanol fraction (NBF), ethyl acetate fraction (EAF), and aqueous fraction (AQF)) were administered intraperitoneally30 minutes before 30 mg/kg pentobarbital intraperitoneal injection; after that, the sleeping time and sleep latency were recorded.

RESULTS

The LD50 value was 2.4 g/kg. The extracts tested showed no negative effect on the proliferation of PC12 cells. A. absinthium extract increased the duration of pentobarbital-induced sleep at doses of 100 and 200 mg/kg (P < 0.01-P < 0.001). Similarly, AQF, EAF, and NBF at 200 mg/kg could increase sleep duration (P < 0.05). The sleep latency was decreased by A. absinthium extract at doses of 100 and 200 mg/kg (P < 0.05-P < 0.01), AQF (P < 0.05), and EAF (P < 0.05). Besides, flumazenil reversed the hypnotic effect of A. absinthium extract (P < 0.05).

CONCLUSION

A. absinthium extract probably demonstrated sleep-enhancing effects by regulating GABAergic system.

Listening to motivational music during warming-up attenuates the negative effects of partial sleep deprivation on cognitive and short-term maximal performance: Effect of time of day

This study assessed the effect of time of day (TOD) and listening to music during warm-up on cognitive and physical performances after partial sleep deprivation (PSD) and normal sleep nights (NSN). In a randomized order, twelve male physical education students [mean (SD) age 20.3 ± 2.0 y; BMI 22.90 ± 3.57 kg/m²)] completed a 30-s Wingate test (i.e., mean (MP) and peak powers (PP)), simple (SRT) and choice reaction times (CRT), a mental rotation test (MRT) and a selective attention test. Measurements were performed at 07:00 h and 17:00 h after a NSN and PSD with and without music, with an in-between recovery period of ≥72. Salivary cortisol was measured before and immediately after the Wingate test. Compared to NSN, the results showed that PSD decreased PP (p < .05, d = 0.86) and MP (p < .01, d = 0.86) in the afternoon. However, compared to NSN, listening to music during the warm up after PSD enhanced PP (p < .01, d = 1.40) and MP (p < .05, d = 0.82) in the morning and PP (p < .05, d = 0.78) in the afternoon. Moreover, listening to music lowered post-exercise cortisol in the morning both after NSN (p < .05, d = 0.79) and PSD (p < .05, d = 0.11). After PSD, music reduced the negative mood states (p < .01, d = 0.94), the SRT (p < .05, d = 0.79) and the CRT (p < .05, d = 0.49) in the afternoon. These findings suggest that listening to music during warm-up (i) enhances cognitive and short-term all out performances after NSN and PSD and (ii) partially counteracts sleep-loss-induced degradation of physical and cognitive performances at both TODs.

Melatonin supplementation improves psychomotor and physical performance in collegiate student-athletes following a sleep deprivation night

Several studies report sleep deprivation negatively impacts post-cognitive and physical performance, and other functions. Recent findings indicate ingestion of melatonin prior to exercise enhances tolerance to training and improves competition. We investigated the effects of melatonin supplementation on psychomotor performance and selected physical fitness measures of collegiate student-athletes following 4 h and 24 h of sleep deprivation. The study employed a repeated-measures, double-blind, randomized controlled protocol with posttest control group design with six conditions [3 sleep conditions (without sleep deprivation, 4 h sleep deprivation (4SD) and 24 h sleep deprivation (24SD)) × 2 supplementation conditions (melatonin and placebo)]. Ten trained male collegiate student-athletes (mean ± SD; age: 20 ± 2 y) attended the laboratory on six occasions with 72 h between successive visits. Placebo or 6 mg of melatonin were administered orally in capsules 30 min before the tests of: static and dynamic balance, reaction time, and anaerobic power. Also, blood lactate was measured before and 3 min after the anaerobic power exercise. During the placebo session, the results indicated that 4SD and 24SD had negative effect on the measured parameters, with higher impacts of the 24SD condition. Compared to placebo and during both 4SD and 24SD conditions, melatonin had a positive effect on static and dynamic balance, anaerobic power, blood lactic acid, and reaction time (p < .05). However, 6 mg melatonin ingestion had no significant effect on all dependent variables in collegiate student-athletes after the night without a sleep deprivation (p > .05). In conclusion, 6 mg of melatonin may be used by student-athletes to improve balance and psychomotor and physical performances after 4 h or 24 h of sleep deprivation.

Sleep Quality's Effect on Vigilance and Perceptual Ability in Adolescent and Adult Athletes

The aim of the study was to investigate the effect of sleep quality in cognitive domains of perceptual ability after exhausting exercise in adolescent and adult athletes. Eighty-six male professional soccer players were included in our study and divided into two groups: adolescents (age: 17.3 ± 0.2 yrs, body mass: 68.9 ± 7.9 kg, body fat: 9.9 ± 3.6 %) versus adults (age: 26.3 ± 5.2 yrs, body mass: 76.5 ± 7.2 kg, body fat: 10.3 ± 3.1 %). For each athlete, prior to cardiopulmonary exercise testing (CPET), anthropometric and morphological characteristics were recorded and Pittsburgh Sleep Quality Index (PSQI) questionnaire was answered. Immediately after CPET, all athletes underwent the perceptual ability test (PATest) for 30 sec and the sum of hits (rep/30 sec) and the time between a visual stimulus and the following stimulus (mean reaction time; RT, sec) were recorded. Oxygen uptake in maximal effort and in anaerobic threshold showed differences between hits (P=0.037) and RT (P=0.025). The variable of PSQI questionnaire "had bad dreams" showed correlation with hits (P=0.021) and RT (P=0.011) and the RT showed correlation with variables "cannot breathe comfortably" (P=0.041) and "...enthusiasm to get things done" (P=0.041). Adolescents showed poorer sleep quality (PSQI score: 5.7 ± 3.6 vs. 2.4 ± 2.6) compared to adults and slower reaction time (0.9 ± 0.1 vs. 0.8 ± 0.1 sec, P=0.029) compared to adolescent athletes with PSQI score ≥5.5. The variable of PSQI score in adolescents is related to HR in maximal effort (r = -0.364, P=0.032) and in adults is related to speed (r = -0.335, P=0.016). Perceptual ability, which requires sustained attention, vigilance, and motor coordination, is often negatively affected by restricted sleep, especially in adolescents.

Sleep Deprived or Concussed? The Acute Impact of Self-Reported Insufficient Sleep in College Athletes

OBJECTIVE

Sleep deprivation is common among both college students and athletes and has been correlated with negative health outcomes, including worse cognition. As such, the current study sought to examine the relationship between sleep difficulties and self-reported symptoms and objective neuropsychological performance at baseline and post-concussion in collegiate athletes.

METHOD

Seven hundred seventy-two collegiate athletes completed a comprehensive neuropsychological test battery at baseline and/or post-concussion. Athletes were separated into two groups based on the amount of sleep the night prior to testing. The sleep duration cutoffs for these group were empirically determined by sample mean and standard deviation (M = 7.07, SD = 1.29).

RESULTS

Compared with athletes getting sufficient sleep, those getting insufficient sleep the night prior to baseline reported significantly more overall symptoms and more symptoms from each of the five symptom clusters of the Post-Concussion Symptom Scale. However, there were no significant differences on objective performance indices. Secondly, there were no significant differences on any of the outcome measures, except for sleep symptoms and headache, between athletes getting insufficient sleep at baseline and those getting sufficient sleep post-concussion.

CONCLUSION

Overall, the effect of insufficient sleep at baseline can make an athlete appear similar to a concussed athlete with sufficient sleep. As such, athletes completing a baseline assessment following insufficient sleep could be underperforming cognitively and reporting elevated symptoms that would skew post-concussion comparisons. Therefore, there may need to be consideration of prior night's sleep when determining whether a baseline can be used as a valid comparison.

M, B.W.C. S, P.V. V, Ramaswamy P. How does cognitive function measured by the reaction time and critical flicker fusion frequency correlate with the academic performance of students?

BACKGROUND

The reaction time (RT) is "the time taken for the appearance of rapid voluntary reaction by an individual following a stimulus, either auditory or visual" and the Critical Flickering Fusion Frequency (CFFF) is "the rate at which successively presented light stimuli appear to be steady and continuous". RT and CFFF are commonly used for the assessment of cognitive functions that are known to influence academic performance. However, data about the exact correlation between these are scarce, particularly in India. This research aimed to study the association between visual RT (VRT), auditory RT (ART) and CFFF and their impact on the academic performance of undergraduate students.

METHODS

This cross-sectional study was conducted on 700 students of Faculty of Medicine and Dentistry at a private medical university in South India, during the period from 2015 to 2017. The VRT, ART and CFFF were evaluated, and the best out of three subsequent attempts was recorded. The mean score (in percentage) of the three best marks out of the five internal assessments for the course during each academic year was considered for analysis. The association between the different cognitive tests and the average academic performance was analysed.

RESULTS

Female students had faster VRT (n = 345, mean = 243.97, SD = 83.87) than male students (n = 273, mean = 274.86, SD = 96.97) (p = 0.001). VRT and ART had a moderate negative correlation with academic performance (for ART, r = - 0.42, p < 0.001; for VRT; r = - 0.40, p < 0.001). CFFF had a very weak positive correlation with academic performance (r = 0.19, p = 0.01). The only independent predictors of academic performance were RT and gender (Adjusted R2 = 0.11).

CONCLUSION

Although there is a correlation between CFFF and cognitive function, our study showed only a weak correlation between CFFF and academic performance. Female students had faster RTs, and gender was an independent predictor of academic performance. Rather, students with faster RTs appear to have an advantage in academic performance.

Partial sleep deprivation affects endurance performance and psychophysiological responses during 12-minute self-paced running exercise

PURPOSE

This study aimed to investigate the effects of partial sleep deprivation (PSD) on physical performance and psychophysiological responses during 12-minute self-paced running exercise.

METHODS

Twenty runners (20.8±1.1 years, 70.6±4.9 kg, 175.1±3.9 cm) performed, in a randomized order, two running self-paced field exercises after a normal sleep night (CONT, bedtime from 22:30 h to 06:30 h) and one night of PSD (bedtime from 00:30 h to 04:30 h). Core temperature and motivation were recorded before exercise. Speed, covered distance, heart rate (HR), rating of perceived exertion (RPE) and respiratory parameters (i.e., minute ventilation (VE), oxygen uptake (VO₂) and carbon dioxide production (VCO₂)) were assessed during exercise. Blood lactate concentration [La] was assessed 2 min after exercise. Simple reaction time (SRT), mood and barrage test (BT) were assessed before and after exercise.

RESULTS

Higher RPE (p=0.01, d=0.90) and lower physical performance (i.e., p=0.001, d=0.59 for running speed and p=0.01, d=0.7 and Δ (%)=-6% for covered distance), following PSD, were obtained compared to CONT. Similarly, PSD attenuated core temperature (p=0.01, d=0.84), HR (p=0.006, ɳp²=0.45), VE (p=0.001, ɳp²=0.73), VO₂ (p=0.001, ɳp²=0.96), BT (p<0.0005, ɳp²=0.86), SRT (p=0.0009, ɳp²=0.44) and mood (p<0.0005). However, VCO₂, [La] and motivation score were not affected by sleep conditions.

CONCLUSION

The decrease of running performance and the increase of physical discomfort after PSD could be the origin of the lower cardio-respiratory responses to the 12-minute self-paced exercise. Effective strategies should be introduced to overcome the deterioration of physical performance and physiological responses after PSD.

The Impact of Sleep on the Relationship between Soccer Heading Exposure and Neuropsychological Function in College-Age Soccer Players

OBJECTIVE

Soccer is the most popular sport worldwide and is the only sport where athletes purposely use their head to deflect the ball during play, termed "heading" the ball. These repetitive head impacts (RHI) are associated with worse neuropsychological function; however, factors that can increase risk of injury following exposure to such head impacts have been largely unexamined. The present study provided a novel examination of the modifying role of sleep on the relationship between RHI exposure and neuropsychological function in college-age soccer players.

METHODS

Fifty varsity and intramural college soccer players completed questionnaires assessing recent and long-term heading exposure, a self-report measure of sleep function, and a battery of neuropsychological tests.

RESULTS

A high level of recent heading exposure was significantly associated with poorer processing speed, independent of concussion history. With reduced sleep duration, a high level of recent heading exposure was related to worse sustained attention. However, with greater hours of sleep duration, heading exposure was related to preserved neuropsychological outcome in sustained attention.

CONCLUSIONS

We replicated our earlier finding of an association between recent head impact exposure and worse processing speed in an independent sample. In addition, we found that sleep may serve as a risk or protective factor for soccer players following extensive exposure to head impacts. Ultimately, this study furthers the understanding of factors impacting neuropsychological function in soccer players and provides empirical support for sleep interventions to help ensure safer soccer play and recovery from injury.

Effect of Angle of View and Partial Sleep Deprivation on Distance Perception

The present study aimed to investigate the effects of intensive effort on egocentric distance perception according to different angles of view after sleep deprivation at the beginning (SDB) or at the end (SDE) of the night and after a normal sleep night (NNS). Ten male students soccer players (age 22.8 ± 1.3 years; body mass 72.0 ± 10.4 kg; body height 180.0 ± 3.0 cm) performed a repeated cycling (RS) exercise (10 × 6 s maximal cycling with 24 s in between) after SDB, SDE, and NNS. They were asked to estimate three distances (i.e. 15, 25, and 35 m) before and after RS from different angles of view [i.e. in front (0°) and in side (45° left and 45° right)]. For 35 m, distance estimation was better during NNS compared to SDB and SDE for the front and the two side angles either before or after RS (p < 0.05). Concerning 25 m, distance estimation was better after compared to before RS for the front angle during the NNS session (p < 0.05). For 15 m, distance estimation was better during NNS than SDB and SDE for the front and both side angles after RS (p < 0.05). We concluded that partial sleep deprivation negatively affected the estimation of the egocentric distance for the three angles of view either at rest or after RS exercise.

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

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

The Influence of 24-hr Sleep Deprivation on Psychomotor Vigilance in Young Women and Men

BACKGROUND

The number of studies on gender differences in psychomotor performance and sleepiness is small and the results are contradictory. The aim of this study was to assess the changes in psychomotor performance, due to 24 h of sleep deprivation in young women and men.

PARTICIPANTS

Eighty-nine students (49 women and 40 men) took part in the study. Participants were randomized into two groups: experimental (sleep deprived) and control (non-sleep deprived).

METHODS

The research was carried out using computer-based tests of the Vienna Test System (COG, DT, WAFF) and pupillography (F²D Fit-For-Duty).

RESULTS

There were no statistically significant effects of the main genders and groups on sleepiness measured by the pupillography. There was no deterioration in the results after deprivation among women and men in the COG test. Changes were noted in the DT and WAFF tests, and their size depended on the test. The number of false responses in psychomotor test was higher in women after sleep deprivation.

CONCLUSION

One night of sleep deprivation may not have been a negative enough stimulus for young, healthy women and men to reveal gender differences in psychomotor tests. Low sleep levels can lead to low productivity at work and accidents due to reduced vigilance. Insufficient sleep in the long term can lead to poor health, resulting in hypertension, obesity and depression.

Sleep quality associated with mood in elite athletes

Objectives: This study aimed to analyze the association between sleep quality and mood in elite athletes of different competitive levels. Methods: Participants were 1041 elite athletes (aged 20.82 ± 6.62 years), with 671 men (64.5%/21.52 ± 6.90 years) and 370 women (35.5%/19.55 ± 5.89 years) from 10 individual sports and 6 team sports. Participants self-reported sleep quality on a Likert-type scale and mood was measured with the Brunel Mood Scale (BRUMS). The data were analyzed using the Kruskal-Wallis test, and binary logistic regression. Results: Results revealed that athletes who compete internationally are 84% more likely to have poor sleep quality than athletes who compete at a regional level. International athletes with good sleep quality showed greater vigor. National athletes with poor sleep quality showed more confusion, depression, and fatigue. Thus, mood and competitive level are factors associated with sleep quality. Confusion, fatigue, and tension impair sleep, and vigor reduces the likelihood of poor sleep. Conclusions: Sleep should be monitored, especially in international level athletes, in order to prevent sleep disorders during competitions. Coaches and athletes should use techniques and strategies for appropriate management of sleep and mood, to maintain the athletes in optimal condition before important competitions.

A hypothesis regarding how sleep can calibrate neuronal excitability in the central nervous system and thereby offer stability, sensitivity and the best possible cognitive function

The function of sleep in mammal and other vertebrates is one of the great mysteries of biology. Many hypotheses have been proposed, but few of these have made even the slightest attempt to explain the essence of sleep - the uncompromising need for reversible unconsciousness. During sleep, epiphenomena - often of a somatic character - occur, but these cannot explain the core function of sleep. One answer could be hidden in the observations made for long periods of time of the function of the central nervous system (CNS). The CNS is faced with conflicting requirements on stability and excitability. A high level of excitability is desirable, and is also a prerequisite for sensitivity and quick reaction times; however, it can also lead to instability and the risk of feedback, with life-threatening epileptic seizures. Activity-dependent negative feedback in neuronal excitability improves stability in the short term, but not to the degree that is required. A hypothesis is presented here demonstrating how calibration of individual neurons - an activity which occurs only during sleep - can establish the balanced and highest possible excitability while also preserving stability in the CNS. One example of a possible mechanism is the observation of slow oscillations in EEGs made on birds and mammals during slow wave sleep. Calibration to a genetically determined level of excitability could take place in individual neurons during the slow oscillation. This is only possible offline, which explains the need for sleep. The hypothesis can explain phenomena such as the need for unconsciousness during sleep, with the disconnection of sensory stimuli, slow EEG oscillations, the relationship of sleep and epilepsy, age, the effects of sleep on neuronal firing rate and the effects of sleep deprivation and sleep homeostasis. This is with regard primarily to mammals, including humans, but also all other vertebrates.

Effect of sleep efficiency on salivary metabolite profile and cognitive function during exercise in volleyball athletes

PURPOSE

Sleep duration is known to affect physiological and circadian metabolites and human homeostasis. However, little is known about the relationship between sleep quality and metabolite and cognitive function during exercise. Therefore, the aim of the present study was to investigate the impact of sleep quality on metabolite level and cognitive function in female volleyball athletes.

METHODS

Twelve female volleyball athletes participated in this study. Sleep efficiency was measured for 1 week using NemuriSCAN (Paramount Bed Co. Ltd., Japan) as an index of sleep quality. The subjects were divided into better (n = 6) and lesser (n = 6) sleep quality groups by the median value of sleep efficiency. Saliva samples were collected using a Salimetric oral swab cotton and salivary metabolites were analysed using capillary electrophoresis and time-of-flight mass spectrometry. The subjects performed Stroop tasks (simple and difficult tasks) at rest and during aerobic exercise in recumbent cycle ergometer at light and heavy intensity.

RESULTS

Increased sleep efficiency was found in the better sleep quality group, whereas total sleep time was similar. There were differences in urea cycle and Krebs cycle metabolites between the two groups; their levels were correlated with sleep efficiency. The difficult-task response time during heavy exercise was faster in the better sleep quality group.

CONCLUSION

We demonstrated that sleep efficiency was associated with urea cycle and Krebs cycle metabolite levels and response time during heavy exercise in volleyball athletes. These results suggested that sleep quality may affect amino acid and energy metabolism and cognitive function during heavy exercise.

Sleep Hygiene for Optimizing Recovery in Athletes: Review and Recommendations

For elite athletes who exercise at a high level, sleep is critical to overall health. Many studies have documented the effects of sleep deprivation in the general population, but few studies exist regarding specific effects in the athlete. This review summarizes the effects of sleep deprivation and sleep extension on athletic performance, including reaction time, accuracy, strength and endurance, and cognitive function. There are clear negative effects of sleep deprivation on performance, including reaction time, accuracy, vigor, submaximal strength, and endurance. Cognitive functions such as judgment and decision-making also suffer. Sleep extension can positively affect reaction times, mood, sprint times, tennis serve accuracy, swim turns, kick stroke efficiency, and increased free throw and 3-point accuracy. Banking sleep (sleep extension prior to night of intentional sleep deprivation before sporting event) is a new concept that may also improve performance. For sports medicine providers, the negative effects of sleep deprivation cannot be overstated to athletes. To battle sleep deprivation, athletes may seek supplements with potentially serious side effects; improving sleep quality however is simple and effective, benefiting not only athlete health but also athletic performance.

Wake up call for collegiate athlete sleep: narrative review and consensus recommendations from the NCAA Interassociation Task Force on Sleep and Wellness

Sleep is an important determinant of collegiate athlete health, well-being and performance. However, collegiate athlete social and physical environments are often not conducive to obtaining restorative sleep. Traditionally, sleep has not been a primary focus of collegiate athletic training and is neglected due to competing academic, athletic and social demands. Collegiate athletics departments are well positioned to facilitate better sleep culture for their athletes. Recognising the lack of evidence-based or consensus-based guidelines for sleep management and restorative sleep for collegiate athletes, the National Collegiate Athletic Association hosted a sleep summit in 2017. Members of the Interassociation Task Force on Sleep and Wellness reviewed current data related to collegiate athlete sleep and aimed to develop consensus recommendations on sleep management and restorative sleep using the Delphi method. In this paper, we provide a narrative review of four topics central to collegiate athlete sleep: (1) sleep patterns and disorders among collegiate athletes; (2) sleep and optimal functioning among athletes; (3) screening, tracking and assessment of athlete sleep; and (4) interventions to improve sleep. We also present five consensus recommendations for colleges to improve their athletes’ sleep.

Effects of High vs. Low Glycemic Index of Post-Exercise Meals on Sleep and Exercise Performance: A Randomized, Double-Blind, Counterbalanced Polysomnographic Study

The aim of the current study was to investigate the effect of the glycemic index of post-exercise meals on sleep quality and quantity, and assess whether those changes could affect the next day’s exercise performance. Following a baseline/familiarization phase, 10 recreationally trained male volunteers (23.2 ± 1.8 years) underwent two double-blinded, randomized, counterbalanced crossover trials. In both trials, participants performed sprint interval training (SIT) in the evening. Post-exercise, participants consumed a meal with a high (HGI) or low (LGI) glycemic index. Sleep parameters were assessed by a full night polysomnography (PSG). The following morning, exercise performance was evaluated by the countermovement jump (CMJ) test, a visual reaction time (VRT) test and a 5-km cycling time trial (TT). Total sleep time (TST) and sleep efficiency were greater in the HGI trial compared to the LGI trial (p < 0.05), while sleep onset latency was shortened by four-fold (p < 0.05) and VRT decreased by 8.9% (p < 0.05) in the HGI trial compared to the LGI trial. The performance in both 5-km TT and CMJ did not differ between trials. A moderate to strong correlation was found between the difference in TST and the VRT between the two trials (p < 0.05). In conclusion, this is the first study to show that a high glycemic index meal, following a single spring interval training session, can improve both sleep duration and sleep efficiency, while reducing in parallel sleep onset latency. Those improvements in sleep did not affect jumping ability and aerobic endurance performance. In contrast, the visual reaction time performance increased proportionally to sleep improvements.