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Purpose: Short sleep duration and poor sleep quality are common in swimmers. Sleep-hygiene strategies demonstrated beneficial effects on several sleep parameters. The present study assessed the impact of a multisession sleep-hygiene training course on sleep in elite swimmers. Methods: Twenty-eight elite swimmers (17 [2] y) participated. The sleep-hygiene strategy consisted of 3 interventions. Sleep was measured by actigraphy for 7 days before the beginning of the intervention (baseline), after the first collective intervention (postintervention), after the second collective intervention (postintervention 2), and, finally, after the individual intervention (postintervention 3). The Epworth Sleepiness Scale (ESS) was completed concurrently. Swimmers were classified into 2 groups: nonsomnolent (baseline ESS score ≤ 10, n = 13) and somnolent (baseline ESS score ≥ 11, n = 15). Results: All swimmers had a total sleep time of <8 hours per night. Sixty percent of swimmers were moderately morning type. Later bedtime, less time in bed, and total sleep time were observed in the somnolent group compared with the nonsomnolent group at baseline. An interaction between training course and group factors was observed for bedtime, with a significant advance in bedtime between baseline, postintervention 2, and postintervention 3 for the somnolent group. Conclusions: The present study confirms the importance of implementing sleep-hygiene strategies, particularly in athletes with an ESS score ≥11. A conjunction of individual and collective measures (eg, earlier bedtime, napping, and delaying morning training session) could favor the total sleep time achieved. [ABSTRACT FROM AUTHOR]

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

Purpose: To evaluate the effects of sporting activities, training loads, and athletes' characteristics on sleep among high-level adolescent athletes, in a controlled training and academic environment. Methods: A total of 128 high-level adolescent athletes (age = 15.2 [2.0] y), across 9 different sports, completed common sleep questionnaires and were monitored daily (7.3 [2.7] d) during a typical in-season training period. Sleep was analyzed using actigraphy and sleep diaries, whereas training load was evaluated using the session rating of perceived exertion, and muscle soreness and general fatigue were reported with the aid of visual analog scales. Separate linear mixed-effects models were fitted, including the athlete as a random effect and the following variables as fixed effects: the sport practiced (categorical predictor), daily training load, age, and sex. Different models were used to compare sleep variables among sports and to assess the influence of training load, age, and sex. Results: The mean total sleep time was 7.1 (0.7) hours. Swimmers presented increased sleep fragmentation, training loads, perceived muscle soreness, and general fatigue compared with athletes who engaged in other sports. Independent of any sport-specific effects, a higher daily training load induced an earlier bedtime and reduced total sleep time and perceived sleep quality, with higher sleep fragmentation. Moreover, female athletes experienced increased total sleep time and worse sleep quality in response to stress compared with those in males. Conclusion: In a controlled training and academic environment, high-level adolescent athletes did not achieve the recommended sleep duration. Impaired sleep quality and quantity could be partially explained by increased training loads. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effects of night‐time (21:00 hours) high‐intensity, intermittent exercise on sleep architecture among well‐trained athletes in a laboratory setting. In a randomized, counterbalanced order, 11 well‐trained male runners completed a simulated trail‐running exercise (TRAIL) on a motorized treadmill and a resting condition (REST; no exercise during the day). After each condition, nocturnal autonomic nervous system activity and core body temperature (CBT) were measured and sleep was analysed using polysomnography and actigraphy. Markers of muscle damage (maximal voluntary contraction [MVC], plasma creatine kinase concentration [CK] and perceived muscle soreness) were recorded before and immediately (POST), 24 hr (H24) and 48 hr (H48) after exercise. TRAIL induced a high level of fatigue and mild exercise‐induced muscle damage, as determined by a reduction in MVC (−9.4%, p <.01, d = −1.36) and increases in [CK] (+176.0%, p <.01, d = 1.49) and perceived muscle soreness (+4.5 UA, p <.01, d = 2.17) compared with REST at H24. A trend for increased non‐rapid eye movement (+4.2%; p =.10; d = 0.86) and reduced rapid eye movement (−4.4%; p =.07; d = −0.87) during sleep was observed for TRAIL compared with the REST condition. Moreover, compared with REST, TRAIL significantly increased CBT and nocturnal HR during the first part of the night. In conclusion, sleep architecture was modified after night‐time, high‐intensity exercise among well‐trained runners. [ABSTRACT FROM AUTHOR]

Introduction: The relationship between blood distribution, body temperature, and sleep/wakefulness states is still unclear. The aim of the present study is to systematically review the potential beneficial effects of bedding strategies (e.g., mattress, mattress topper or pillow) on body cooling and night-time sleep., Material & Methods: This systematic review with meta-analysis searched PubMed, ScienceDirect and Web of Science, from inception until March 4, 2024. We included randomized controlled trials aiming to investigate any type of bedding that induced body cooling compared to habitual sleep environment on sleep parameters in healthy adults. Two reviewers independently extracted data, appraised risk of bias by Cochrane tool, and estimated the mean differences between groups with 95% confidence interval. Meta-analyses and proportional meta-analyses were performed depending on the type of variable. The certainty of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation system., Results: From 3454 articles screened, 9 studies met the inclusion criteria. Overall, with the certainty of the evidence ranging from very low to low we found no differences between groups on sleep onset latency, sleep efficiency, sleep proportion spent in each sleep stage (i.e. N1, N2, N3 and REM), wake after sleep onset, and total sleep time. Results could be interpreted with caution due to high heterogeneity in the estimated effects., Conclusion: With uncertainty of evidence, that ranged from very low to low, different bedding strategies had no effects on night-time sleep characteristics; however, the studies included into the qualitative synthesis suggested an effect of different bedding strategies on body cooling (i.e., lower core body temperature, p < 0.05) from an acute perspective. Future studies on various forms of bedding interventions susceptible to favour and maintain sleep through a positive body thermal effect are highly warranted., Prospero Registration: CRD42021275369., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)