Effects of Evening Exercise on Sleep in Healthy Participants: A Systematic Review and Meta-Analysis

Sleep During the COVID-19 Pandemic: Longitudinal Observational Study Combining Multisensor Data With Questionnaires

BACKGROUND

The COVID-19 pandemic prompted various containment strategies, such as work-from-home policies and reduced social contact, which significantly altered people's sleep routines. While previous studies have highlighted the negative impacts of these restrictions on sleep, they often lack a comprehensive perspective that considers other factors, such as seasonal variations and physical activity (PA), which can also influence sleep.

OBJECTIVE

This study aims to longitudinally examine the detailed changes in sleep patterns among working adults during the COVID-19 pandemic using a combination of repeated questionnaires and high-resolution passive measurements from wearable sensors. We investigate the association between sleep and 5 sets of variables: (1) demographics; (2) sleep-related habits; (3) PA behaviors; and external factors, including (4) pandemic-specific constraints and (5) seasonal variations during the study period.

METHODS

We recruited working adults in Finland for a 1-year study (June 2021-June 2022) conducted during the late stage of the COVID-19 pandemic. We collected multisensor data from fitness trackers worn by participants, as well as work and sleep-related measures through monthly questionnaires. Additionally, we used the Stringency Index for Finland at various points in time to estimate the degree of pandemic-related lockdown restrictions during the study period. We applied linear mixed models to examine changes in sleep patterns during this late stage of the pandemic and their association with the 5 sets of variables.

RESULTS

The sleep patterns of 27,350 nights from 112 working adults were analyzed. Stricter pandemic measures were associated with an increase in total sleep time (TST) (β=.003, 95% CI 0.001-0.005; P<.001) and a delay in midsleep (MS) (β=.02, 95% CI 0.02-0.03; P<.001). Individuals who tend to snooze exhibited greater variability in both TST (β=.15, 95% CI 0.05-0.27; P=.006) and MS (β=.17, 95% CI 0.03-0.31; P=.01). Occupational differences in sleep pattern were observed, with service staff experiencing longer TST (β=.37, 95% CI 0.14-0.61; P=.004) and lower variability in TST (β=-.15, 95% CI -0.27 to -0.05; P<.001). Engaging in PA later in the day was associated with longer TST (β=.03, 95% CI 0.02-0.04; P<.001) and less variability in TST (β=-.01, 95% CI -0.02 to 0.00; P=.02). Higher intradaily variability in rest activity rhythm was associated with shorter TST (β=-.26, 95% CI -0.29 to -0.23; P<.001), earlier MS (β=-.29, 95% CI -0.33 to -0.26; P<.001), and reduced variability in TST (β=-.16, 95% CI -0.23 to -0.09; P<.001).

CONCLUSIONS

Our study provided a comprehensive view of the factors affecting sleep patterns during the late stage of the pandemic. As we navigate the future of work after the pandemic, understanding how work arrangements, lifestyle choices, and sleep quality interact will be crucial for optimizing well-being and performance in the workforce.

Predicting long-term sleep deprivation using wearable sensors and health surveys

Sufficient sleep is essential for individual well-being. Inadequate sleep has been shown to have significant negative impacts on our attention, cognition, and mood. The measurement of sleep from in-bed physiological signals has progressed to where commercial devices already incorporate this functionality. However, the prediction of sleep duration from previous awake activity is less studied. Previous studies have used daily exercise summaries, actigraph data, and pedometer data to predict sleep during individual nights. Building upon these, this article demonstrates how to predict a person's long-term average sleep length over the course of 30 days from Fitbit-recorded physical activity data alongside self-report surveys. Recursive Feature Elimination with Random Forest (RFE-RF) is used to extract the feature sets used by the machine learning models, and sex differences in the feature sets and performances of different machine learning models are then examined. The feature selection process demonstrates that previous sleep patterns and physical exercise are the most relevant kind of features for predicting sleep. Personality and depression metrics were also found to be relevant. When attempting to classify individuals as being long-term sleep-deprived, good performance was achieved across both the male, female, and combined data sets, with the highest-performing model achieving an AUC of 0.9762. The best-performing regression model for predicting the average nightly sleep time achieved an R-squared of 0.6861, with other models achieving similar results. When attempting to predict if a person who previously was obtaining sufficient sleep would become sleep-deprived, the best-performing model obtained an AUC of 0.9448.

Older adults exercising ON TIME: protocol for a randomized controlled cross-over study to assess the effect of physical activity timing on insomnia severity

BACKGROUND

There are increased indications that physical activity timing, irrespective of intensity, impacts insomnia and circadian clock function. Here, we describe the rationale and design of a randomized cross-over study, called ON TIME, to examine the effects of (changing) physical activity timing on insomnia severity and on multiple exploratory outcomes that are linked to circadian clock function.

METHODS

We will conduct a randomized cross-over trial in 40 healthy older adults (aged 65 to 75 years) with subclinical or clinical insomnia (Insomnia Severity Index (ISI) scores of ≥ 10) from the Dutch municipality of Leiden and surroundings. Participants will undergo 3 intervention periods (14 days each) consecutively: one sedentary period and two periods of increased physical activity (one period with morning activity and one period with evening activity). The intervention periods are separated by a wash-out period of 1 week. In both active intervention arms, participants will follow coached or uncoached outdoor physical exercise sessions comprising endurance, strength, and flexibility exercises for 14 days. The primary outcome is change in insomnia severity as measured by the ISI. Additional exploratory outcomes include multiple components of objective sleep quality measured with tri-axial accelerometry and subjective sleep quality assessed by questionnaires as well as dim light melatonin onset and 24-h rhythms in heart rate, heart rate variability, breathing rate, oxygen saturation, mood, and objective emotional arousal and stress. Additionally, we will collect diary data on eating patterns (timing and composition). Finally, fasting blood samples will be collected at baseline and after each intervention period for measurements of biomarkers of metabolic and physiological functioning and expression of genes involved in regulation of the biological clock.

DISCUSSION

We anticipate that this study will make a significant contribution to the limited knowledge on the effect of physical activity timing. Optimizing physical activity timing has the potential to augment the health benefits of increased physical exercise in the aging population.

TRIAL REGISTRATION

Trial was approved by the Medical Ethics Committee Leiden, The Hague, Delft, The Netherlands (June, 2023). The trial was registered in the CCMO-register https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm under study ID NL82335.058.22 and named ("Ouderen op tijd in beweging" or in English "Older adults exercising on time"). At time of manuscript submission, the trial was additionally registered at ClinicalTrials.gov under study ID: NL82335.058.22 and is awaiting approval.

An acute bout of high-intensity exercise affects nocturnal sleep and sleep-dependent memory consolidation

Acute exercise has been shown to affect long-term memory and sleep. However, it is unclear whether exercise-induced changes in sleep architecture are associated with enhanced memory. Recently, it has been shown that exercise followed by a nap improved declarative memory. Whether these effects transfer to night sleep and other memory domains has not yet been studied. Here, we investigate the influence of exercise on nocturnal sleep architecture and associations with sleep-dependent procedural and declarative memory consolidation. Nineteen subjects (23.68 ± 3.97 years) were tested in a balanced cross-over design. In two evening sessions, participants either exercised (high-intensity interval training) or rested immediately after encoding two memory tasks: (1) a finger tapping task and (2) a paired-associate learning task. Subsequent nocturnal sleep was recorded by polysomnography. Retrieval was conducted the following morning. High-intensity interval training lead to an increased declarative memory retention (p = 0.047, d = 0.40) along with a decrease in REM sleep (p = 0.012, d = 0.75). Neither procedural memory nor NREM sleep were significantly affected. Exercise-induced changes in N2 showed a positive correlation with procedural memory retention which did not withstand multiple comparison correction. Exploratory analyses on sleep spindles and slow wave activity did not reveal significant effects. The present findings suggest an exercise-induced enhancement of declarative memory which aligns with changes in nocturnal sleep architecture. This gives additional support for the idea of a potential link between exercise-induced sleep modifications and memory formation which requires further investigation in larger scaled studies.

Evening regular activity breaks extend subsequent free-living sleep time in healthy adults: a randomised crossover trial

Objective

To determine if performing regular 3-min bouts of resistance exercise spread over 4 hours in an evening will impact subsequent sleep quantity and quality, sedentary time and physical activity compared with prolonged uninterrupted sitting.

Methods

In this randomised crossover trial, participants each completed two 4-hour interventions commencing at approximately 17:00 hours: (1) prolonged sitting and (2) sitting interrupted with 3 min of bodyweight resistance exercise activity breaks every 30 min. On completion, participants returned to a free-living setting. This paper reports secondary outcomes relating to sleep quality and quantity, physical activity and sedentary time which were assessed using wrist-worn ActiGraph GT3+ accelerometers paired with a sleep and wear time diary.

Results

A total of 28 participants (women, n=20), age 25.6±5.6 years, body mass index 29.5±6.7 kg/m2 (mean±SD) provided data for this analysis. Compared with prolonged sitting, regular activity breaks increased mean sleep period time and time spent asleep by 29.3 min (95% CI: 1.3 to 57.2, p=0.040) and 27.7 min (95% CI: 2.3 to 52.4, p=0.033), respectively, on the night of the intervention. There was no significant effect on mean sleep efficiency (mean: 0.2%, 95% CI: -2.0 to 2.4, p=0.857), wake after sleep onset (1.0 min, 95% CI: -9.6 to 11.7, p=0.849) and number of awakenings (0.8, 95% CI: -1.8 to 3.3, p=0.550). Subsequent 24-hour and 48-hour physical activity patterns were not significantly different.

Conclusions

Performing bodyweight resistance exercise activity breaks in the evening has the potential to improve sleep period and total sleep time and does not disrupt other aspects of sleep quality or subsequent 24-hour physical activity. Future research should explore the longer-term impact of evening activity breaks on sleep.

Trial registration number

Australian New Zealand Clinical Trials Registry (ACTRN12621000250831).

Effects of intensity, frequency, and time window of exercise on sleep quality among community-dwelling adults aged 65-86 years

BACKGROUND

Although the effects of exercise training (ET) on sleep problem have been reported, the effects according to the components of exercise, including intensity, frequency, and time window, are unknown. Thus, in this study, we aimed to assess the effects of ET on sleep quality in community-dwelling older adults with sleep problems.

METHODS

We evaluated individuals aged ≥65 years whose Pittsburgh sleep quality index was >5 points at baseline. The participants were allocated to either the control group or the ET group and underwent interval walking training (IWT) for 5 months. Information regarding intensity, frequency, and time window of ET were obtained using a waist-worn accelerometer.

RESULTS

Overall, 63 participants (24 men [mean ± standard deviation age: 75.1 ± 4.6 years] and 39 women [74.7 ± 5.2 years]) and 65 participants (24 men [75.2 ± 4.0 years] and 41 women [73.6 ± 4.2 years]) were included in the ET and control groups, respectively. The change in Pittsburgh sleep quality index was not significantly different between the two groups for both sexes. In the ET group, women who exercised 3-8 h before bedtime, men who did ET > 8 h before bedtime and more than 1 h after waking up, and men who did ET ≥ 5.05 days/week experienced significant improvements compared to the baseline.

CONCLUSIONS

IWT does not significantly improve sleep quality. To obtain improvements in sleep quality, it might be necessary to consider the time window of performing ET for both sexes and ET frequency for men.

Sleep hygiene - What do we mean? A bibliographic review

There is no consensus on the definition of sleep hygiene and its components. We examined the definition of sleep hygiene based on its use in published studies. Four databases (Medline, EMBASE, PsycINFO and CINAHL) were searched from inception until December 31, 2021 for the phrase 'sleep hygiene' in the title or abstract. We identified 548 relevant studies in adults: 250 observational and 298 intervention studies. A definition of sleep hygiene was provided in only 44% of studies and converged on three themes: behavioural factors, environmental factors, and an aspect of control. Sleep hygiene components were explicitly defined in up to 70% of observational studies, but in only 35% of intervention studies. The most commonly considered components of sleep hygiene were caffeine (in 51% of studies), alcohol (46%), exercise (46%), sleep timing (45%), light (42%), napping (39%), smoking (38%), noise (37%), temperature (34%), wind-down routine (33%), stress (32%), and stimulus control (32%), although the specific details of each component varied. Lack of consistency in definitions of sleep hygiene and its components may hinder communication between researchers, clinicians, and the public, and likely limits the utility of sleep hygiene as an intervention.

The effects of exercise programs on sleep architecture in obstructive sleep apnea: a meta-analysis of randomized controlled trials

OBJECTIVES

Exercise is an effective intervention for obstructive sleep apnea (OSA). However, the effects of exercise on objective sleep architecture in patients with OSA remain unknown. This meta-analysis aimed to collect data from randomized controlled trials of exercise interventions in patients with OSA, with a specific focus on objective sleep parameters derived from polysomnography.

METHODS

Randomized control trials that targeted patients with OSA aged >18 years, measured sleep using polysomnography after exercise programs, and reported the proportion of sleep stages were included for meta-analysis. Bias was assessed using the revised Cochrane risk-of-bias tool and funnel plots. The random effects model was applied.

RESULTS

Six studies with a total of 236 patients were included in the meta-analysis. There were no significant differences in the total sleep time (TST), sleep efficiency, sleep onset latency, stage N1 sleep, or rapid eye movement sleep between the exercise and control groups. Participation in an exercise program lasting >12 weeks significantly decreased stage N2 and increased stage N3 sleep as observed in the subgroup analysis. Although this tendency did not reach statistical significance in the total-group analysis, it was significant after excluding the possible confounding effects of heart disease.

CONCLUSIONS

The exercise program decreased N2 and increased N3 proportions over the TST among patients with OSA, which may correspond to subjective sleep quality. The beneficial effects were significant when the program lasted >12 weeks and after excluding the confounding effects of heart disease. Exercise program duration should be considered when providing clinical advice.

Effectiveness of multi-modal home-based videoconference interventions on sleep in older adults: study protocol for a randomized controlled trial

Aging is characterized by substantial changes in sleep architecture that negatively impact fitness, quality of life, mood, and cognitive functioning. Older adults often fail to reach the recommended level of physical activity to prevent the age-related decline in sleep function, partly because of geographical barriers. Implementing home-based interventions could surmount these obstacles, thereby encouraging older adults to stay active, with videoconference administration emerging as a promising solution. Increasing the availability of biological rhythms synchronizers, such as physical activity, light exposure, or vestibular stimulation, represents a viable non-pharmacological strategy for entraining circadian rhythms and potentially fortifying the sleep-wake cycle, thereby enhancing sleep in aging. This study aims to (1) assess the impact of remote physical exercise training and its combination with bright light exposure, and (2) investigate the specific contribution of galvanic vestibular stimulation, to sleep quality among healthy older adults with sleep complaints. One hundred healthy older adults aged 60-70 years with sleep complaints will be randomly allocated to one of four groups: a physical exercise training group (n = 25), a physical exercise training combined with bright light exposure group (n = 25), a galvanic vestibular stimulation group (n = 25) or a control group (i.e., health education) (n = 25). While physical exercise training and health education will be supervised via videoconference at home, bright light exposure (for the physical exercise training combined with bright light exposure group) and vestibular stimulation will be self-administered at home. Pre-and post-tests will be conducted to evaluate various parameters, including sleep (polysomnography, subjective questionnaires), circadian rhythms (actigraphy, temperature), fitness (physical: VO2 peak, muscular function; and motor: balance, and functional mobility), cognition (executive function, long-term memory), quality of life and mood (anxiety and depression). The findings will be anticipated to inform the development of recommendations and non-pharmaceutical preventive strategies for enhancing sleep quality in older adults, potentially leading to improvements in fitness, cognition, quality of life, and mood throughout aging.

Assessing the daily association of sleep hygiene behaviours with sleep: A between and within persons approach

Sleep hygiene behaviours are recommendations given to both clinical and non-clinical populations with a focus on modifying behaviours to maximise sleep outcomes. However, methodological issues present in sleep hygiene research make it difficult to conclusively determine the impact of each behaviour. This study aimed to address these issues by adopting a two-week, repeated measures design which incorporated objective sleep measures and used linear mixed effect modelling to assess the daily association of a wide range of sleep hygiene behaviours on sleep in a non-clinical, university sample. Between-persons effects revealed that bedtime and frequency of daytime napping, alcohol use, and social media use were negatively related to sleep duration while waketime and frequency of too much water consumption were positively related to sleep duration. Within-person effects revealed that later than usual bedtime, earlier than usual waketime, no sunlight exposure, poor ventilation, having an unpleasant conversation before bed were negatively associated with sleep duration whereas using alcohol to deliberately help full asleep was positively related to sleep duration. In contrast, disproportionately more behaviours were not significantly related to either sleep outcome, only some of which could be explained by individual differences, which suggests that more research is needed to determine the conditions under which these behaviours affect sleep, if at all.

Associations between muscle dysmorphia symptomatology and sleep duration and difficulty in the Canadian Study of Adolescent Health Behaviors

OBJECTIVES

Prior research has shown links between mental health symptomatology and poor sleep. However, associations between muscle dysmorphia symptomatology and poor sleep remain unknown, which was the aim of this study.

METHODS

Data from the Canadian Study of Adolescent Health Behaviors (2021-2022) were analyzed (N = 912). Multinomial logistic regression analyses and logistic regression analyses were used to determine the association between muscle dysmorphia symptomatology and average sleep duration (5 hours or less, 6 hours, 7 hours, and 8 or more hours) and difficulty falling or staying asleep over a 2-week period.

RESULTS

Findings indicated significant associations between muscle dysmorphia symptomatology and shorter sleep duration and greater sleep difficulty in both cross-sectional and prospective analyses.

CONCLUSIONS

The findings from this study underscore poor sleep as a correlate of muscle dysmorphia symptomatology among adolescents and young adults, emphasizing the need for screening and interventions in healthcare settings.

The effects of physical activity on sleep architecture and mood in naturalistic environments

Physical activity has been found to alter sleep architecture, but these effects have been studied predominantly in the laboratory and the generalizability of these findings to naturalistic environments and longer time intervals, as well as their psychological effects, have not been evaluated. Recent technological advancements in wearable devices have made it possible to capture detailed measures of sleep outside the lab, including timing of specific sleep stages. In the current study, we utilized photoplethysmography coupled with accelerometers and smartphone ambulatory assessment to collect daily measurements of sleep, physical activity and mood in a sample of N = 82 over multi-month data collection intervals. We found a robust inverse relationship between sedentary behavior and physical activity and sleep architecture: both low-intensity and moderate-to-vigorous physical activity were associated with increased NREM sleep and decreased REM sleep, as well as a longer REM latency, while higher levels of sedentary behavior showed the opposite pattern. A decreased REM/NREM ratio and increased REM latency were in turn associated with improved wellbeing, including increased energy, reduced stress and enhanced perceived restfulness of sleep. Our results suggest that physical activity and sleep account for unique variance in a person's mood, suggesting that these effects are at least partially independent.

Early morning sport scheduling is associated with poorer subjective sleep characteristics in British student-athletes

This study presents the sleep characteristics of British student-athletes and examines the relationships between sport scheduling and time demands on sleep outcomes. Student-athletes (n = 157, 51% male) completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and the Sleep Hygiene Index (SHI). Self-reported sleep characteristics on weekdays and weekends, weekly frequencies of early morning and late evening sport sessions, and academic-related and sport-related time demands were also collected. Questionnaires revealed a high prevalence of undesired sleep characteristics including poor sleep quality (global PSQI >5 in 49.0%) and low sleep durations on weekdays (25% reporting <7 h). Paired t-tests revealed significant differences in bedtime, waketime, sleep duration, and sleep onset latency between weekdays and weekends (all p < 0.01). Hierarchical regression analyses indicated that early morning sport frequency was a significant predictor of PSQI (β = 0.30) and SHI (β = 0.24) global scores, weekday waketimes (β = -0.17), and weekday sleep durations (β = -0.25; all p < 0.05) in models adjusted for participant characteristics. Late evening sport frequency, and academic-related and sport-related time demands, were not significant predictors of any sleep outcome. Adjusting sport scheduling to avoid early start times could provide a means to improve sleep outcomes and may improve sporting performance and academic attainment.

Does sleep promote adaptation to acute stress: An experimental study

Objectives

Evidence of the impact of chronic stress on sleep is abundant, yet experimental sleep studies with a focus on acute stress are scarce and the results are mixed. Our study aimed to fill this gap by experimentally investigating the effects of pre-sleep social stress on sleep dynamics during the subsequent night, as measured with polysomnography (PSG).

Methods

Thirty-four healthy individuals (65% females, Mage = 25.76 years SD = 3.35) underwent a stress-inducing (SC) or neutral control condition (CC) in virtual reality (VR). We used overnight EEG measurements to analyze the basic sleep parameters and power spectral density (PSD) across the sleep cycles, and measured heart rate and its variability (HRV), skin electrodermal activity (EDA), and salivary cortisol to capture physiological arousal during the VR task and the pre-sleep period.

Results

Following acute stress (SC), the amount of slow-wave sleep (SWS) was higher and N2 sleep lower relative to CC, specifically in the first sleep cycle. In SC, PSD was elevated in the beta-low (16-24 Hz) and beta-high (25-35 Hz) frequency ranges during both stages N2 and SWS over the entire night.

Conclusions

Sleep promoted adaptation to acute social stress by a longer duration of SWS in the subsequent sleep period, especially in early sleep. A similar homeostatic effect towards restorative sleep is well-evidenced in animal model stress studies but has not been previously reported in experimental human studies. Whether the high-frequency PSD activity during stages N2 and SWS also serves in the resolution of transient stress, remains open.

The relationship between nighttime exercise and problematic smartphone use before sleep and associated health issues: a cross-sectional study

OBJECTIVE

Physical exercise has the potential to mitigate addictive behaviors and relevant health issues. However, the nighttime exercise has not been studied regarding this research topic. This study aims to explore the association between nocturnal physical exercise and problematic smartphone use before sleep, as well as related health issues.

METHODS

To explore the association between nighttime physical exercise and problematic smartphone use before sleep as well as related health issues, we conducted a cross-sectional survey among 1,334 college students. Their daily exercise behaviors (including timeframe, rationale, frequency, and duration), smartphone use before sleep, sleep quality, smartphone addiction, anxiety, and depression were measured by questionnaires. The associations were assessed using generalized linear models.

RESULTS

Our findings indicate that nearly 70% of participants chose to perform exercise at nighttime. Among these individuals who exercised at nighttime, the frequency and duration of nighttime exercise were significantly associated with decreased probabilities of smartphone use before sleep. Additionally, the frequency and duration of nighttime exercise were associated with lower levels of smartphone addiction and anxiety disorders.

CONCLUSION

Nighttime Exercise behaviors can effectively reduce sleep delays caused by problematic smartphone use before bedtime. These findings contribute to understanding the potential effects of nighttime exercise on problematic smartphone use and relevant health issues. Future research should employ more precise methodologies to examine these associations.

Effects of morning and evening physical exercise on subjective and objective sleep quality: an ecological study

To optimise the relationship between exercise and sleep quality, the intensity of exercise and its proximity to sleep are key factors to manage. Although low-to-moderate exercises promote sleep quality, late-evening vigorous exercise instead of morning should still be avoided. It potentially impacts the objective and subjective markers of sleep quality. In the present study, we investigated the effects of vigorous morning and evening exercise on objective and subjective sleep features in an ecological context. A total of 13 recreational runners (mean [SD] age 27.7 [7.2] years, four females) performed a 45-60 min run (70% maximal aerobic velocity) either in the MORNING (30 min to 2 h after waking-up) or in the EVENING (2 h to 30 min before sleep). The two exercise conditions were separated by a REST day. After each condition, sleep was objectively assessed using an electroencephalographic headband and subjectively using the Spiegel Sleep Inventory. Compared with REST, both MORNING and EVENING exercise increased the time spent in non-rapid eye movement (NREM, +24.9 min and +22.7 min; p = 0.01, η2  = 0.11, respectively). Longer NREM duration was mainly due to sleep stage 2 extension after both MORNING (+20.8 min) and EVENING (+22.8 min) exercise relative to REST (p = 0.02, η2  = 0.12). No other effect of exercise on either objective or subjective sleep could be observed. Exercise, independently of the time at which it takes place, leads to extended NREM sleep without other effects on sleep quality. Considering the crucial role of exercise in achieving good health, sleep hygiene guidelines should be updated to promote exercise at any time of the day.

Effects of exercise on sleep in children with overweight/obesity: a randomized clinical trial

OBJECTIVE

The objective of this study was to examine the chronic effects of a 20-week exercise training program on device-assessed sleep and sleep-disordered breathing; and to determine whether participating in a session of the exercise program had effects on device-assessed sleep the subsequent night in children with overweight/obesity.

METHODS

A randomized clinical trial was conducted from November 2014 to June 2016. A total of 109 children (age 8-11 years) with overweight/obesity were randomized into an exercise training or control group. The exercise program included aerobic and resistance training 3 to 5 days/week. The control group participants continued their usual lifestyle. Device-assessed sleep outcomes were measured using wrist-worn actigraphy at baseline, in the middle of the exercise program (10th week), and at postintervention for seven consecutive days (24 h/day), and sleep-disordered breathing was measured via the Pediatric Sleep Questionnaire.

RESULTS

The exercise training program had a statistically significant effect on wake after sleep onset time (-10.8 min/day, -0.5 SDs, p = 0.040). No other chronic or acute effects (i.e., the subsequent night of attending a session of the exercise training program) were observed on the remaining sleep outcomes.

CONCLUSIONS

A 20-week exercise training program reduced wake after sleep onset time in children with overweight/obesity. Future randomized trials that include a sample of children with poor sleep health at baseline are needed to better appreciate the role of exercise in sleep health.

An RCT META analysis based on the effect of tai chi exercise therapy on the outcome of elderly patients with moderate-to-severe sleep disorders-A systematic review study

Background

According to statistics, about one-fifth of the world's elderly people suffer from sleep disorders, and the problem of sleep disorders in the elderly is extremely serious, and this problem is one of the important causes of chronic diseases such as hypertension, hyperlipidemia, diabetes mellitus, and coronary heart disease in the elderly. The positive effect of Tai Chi exercise therapy on sleep problems has been confirmed, but at present, the effect of the specific duration of Tai Chi exercise on the improvement of elderly people with moderate to severe sleep disorders varies.

Objective

META analysis was used to investigate and find that long-term Tai Chi exercise therapy has the best effect on improving sleep in elderly patients with moderate to severe sleep disorders. Methods: META analysis was performed using Revman 5.3 after searching Web of science, Pubmed, Scopus, The Cochroae Library, OVID, CBM, CNKI, VIP, and other databases, and then filtering and extracting.

Results

A total of seven papers were included. Meta-analysis showed that tai chi exercise was more effective in improving sleep problems in elderly patients with sleep disorders compared to the control group, and the difference was significant. This was demonstrated by a decrease in the global Pittsburgh Sleep Quality Index (PSQI) score [SMD = -0.66, 95 % CI (-0.91, -0.41), P < 0.00001], as well as its subdomains of subjective sleep quality [SMD = -0.79, 95 % CI (-1.06, -0.52), P < 0.00001], sleep latency [SMD = -0.80, 95 % CI (-1.21, -0.40), P < 0.00001], sleep duration [SMD = -0.38, 95 % CI (-0.72, -0.04), P = 0.03], habitual sleep efficiency [SMD = -0.58, 95 % CI (-0.84, -0.31), P < 0.0001], sleep disturbance [SMD = -0.51, 95 % CI (-0.78, -0.25), P = 0.00001] and daytime dysfunction [SMD = -0.33, 95 % CI (-0.59, -0.07), P = 0.01]. Improvement was also observed in the Epworth Sleepiness Scale (ESS) and Insomnia Severity Index Scale (ISI). The results showed that the optimal duration and frequency of Tai Chi exercise therapy for improving moderately severe elderly patients with sleep disorders was long-term.

Conclusion

This study systematically assessed the efficacy of Tai Chi exercise therapy for elderly patients with moderate-to-severe sleep disorders. Through a meta-analysis of relevant randomized controlled trials (RCTs), it aims to determine the effectiveness of Tai Chi exercise in improving sleep quality in elderly patients with moderate-to-severe sleep disorders, as well as to compare its effects with those of traditional treatments; to analyze the safety of Tai Chi exercise for this patient population and assess its feasibility as a non-pharmacological therapy; and to fill the research gaps and provide more comprehensive and systematic evidence support. This study provides a practical approach to reducing the risk of medication side effects in older adults with sleep disorders and offers a potentially effective non-pharmacological treatment option, especially for those who are unable or unwilling to use medication. Tai chi exercise may not only improve sleep, but also improve coordination, muscle strength, balance, and reduce stress and anxiety in older adults. It also helps older adults socialize and enhances their social connections and emotional support. This study suggests that community centers or activity centers for the elderly can organize tai chi classes to promote the participation of older adults, and can be used as a scientific exercise rehabilitation tool in clinical treatment, incorporating tai chi practice into daily life, such as tai chi practice at a fixed time every day or every week, which not only helps to improve the sleep disorders of older adults, but also improves their overall quality of life.

[Research Progress in the Effect of Exercise Intervention on Sleep Disorders and the Mechanisms Involved]

Sleep disorders, a common concern in modern society, seriously affect people's physical and mental health. Reported findings suggest that both acute exercise intervention and long-term regular exercise intervention can improve the disrupted sleep structure and normalize the duration and proportion of the different phases of sleep. Moreover, exercise intervention has a positive effect on the endocrine functions, the metabolic functions, the immune response, the autonomic nervous system, and cardiac functions during sleep. It is a non-medicative therapeutic strategy for improving sleep disorders. The specific type of exercise intervention (aerobic exercise, resistance exercise, or meditative movement) adopted is one of the moderating variables of exercise intervention programs. Different types of exercise improve sleep disorders by way of different mechanisms. Exercise volume and intensity are another moderating variable of exercise intervention programs. The optimal amount and intensity of exercise for different individuals to improve sleep disorders may vary. Exercise interventions implemented at the different times throughout a day can also have varying degrees of impact on sleep disorders and there is no consensus on the optimal exercise time for improving sleep quality at present. Herein, we summarized the mechanisms by which exercise intervention improves sleep disorders from four perspectives, including epigenetics, hyperarousal, human circadian rhythm, and body temperature regulation. In addition, we discussed the current gaps and prospects of research in this field, aiming to provide a theoretical basis for the development of exercise prescriptions for sleep disorders.

Effect of physical activity on sleep problems in sedentary adults: a scoping systematic review

This systematic review was steered forward with the aim of analyzing how different forms of exercise could influence the objective and subjective sleep outcome among sedentary adults with sleep problems. A pre-detailed study protocol (PROSPERO ID: CRD42021229649) was used to search for RCTs through five databases. The methodological quality of the included RCTs was assessed by PEDro and studies were included if they scored > 5. Effect size of all outcome measures were calculated using Cohen's d. Of the 4154 studies, 19 studies met the inclusion criteria and underwent quality assessment using 11-point PEDRO scale. 9 studies with PEDro score > 5 were finally included in this systematic review out of which, participants of 4 studies had insomnia (nrange = 37-48, agerange = 44-60 years), 3 studies had poor sleep quality (nrange = 80-275, agerange = 52-70 years) and 2 studies had obstructive sleep apnea syndrome (nrange = 26-68, agerange = 51 years). Majority of studies revealed that physical activity seems to have greater improvement with a large effect size on subjective sleep outcomes among sedentary adults with sleep problems like insomnia, poor sleep quality and OSAS, whereas limited studies and non-significant results were observed on objective sleep outcomes. Physical activity improves sleep outcomes especially among sedentary middle-aged and older adults. More research is needed to examine the effect of physical activity programs on objective sleep outcomes especially in younger sedentary adults with different sleep problems.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00494-w.

Association of sociodemographic, anthropometric, and sleep quality factors with accelerometer-measured sitting and physical activity times among Emirati working women during the COVID-19 pandemic: A cross-sectional study

BACKGROUND

Although a significant lack of physical activity has been linked to an increase in obesity among Emirati women, the factors associated with accelerometer-measured sitting and physical activity times in Emirati women remain unclear.

OBJECTIVES

To explore the association of accelerometer-measured sitting and physical activity times with sociodemographic, anthropometric, and sleep quality factors among Emirati working women.

DESIGN

A cross-sectional study.

METHODS

A convenience sample of 163 healthy working Emirati women aged 18-45 years was used. Sedentary and physical activity times were measured using the Fibion accelerometers worn on the thighs for 4-7 days. General demographic information, anthropometric measurements, and self-reported sleep quality (Pittsburgh sleep quality index score) were collected. Only participants who had valid data (i.e. wear time of ⩾600 min (10 h) per day for a minimum of 4-7 days) were evaluated. All values were normalized to a 16-h day to mitigate differences in wear time among the participants.

RESULTS

Overall, 110 Emirati women were included. The mean sitting time per 16-h day was 11.6 ± 1.1 h; mean moderate activity time per day, 40.88 ± 17.99 min; and mean vigorous activity time per day, 2.41 ± 1.21 min. Longer sitting time was associated with high body fat, secondary education, and divorce. Sitting time was reduced in those with good sleep quality. Moderate-to-vigorous physical activity time was increased in women with postgraduate education and was decreased in women with a longer work experience and with comorbidities. The total activity time increased with increasing age and good sleep quality, whereas it decreased with increasing body fat, presence of at least one comorbidity, secondary education, and divorce.

CONCLUSION

Certain demographic, anthropometric, and sleep quality factors were associated with accelerometer-measured sitting and physical activity times among Emirati working women. Future longitudinal studies should consider these factors when investigating predictors of physical activity levels in this population.

Healthy sleep practices for shift workers: consensus sleep hygiene guidelines using a Delphi methodology

STUDY OBJECTIVES

The unique requirements of shift work, such as sleeping and working at variable times, mean that current sleep hygiene guidelines may be inappropriate for shift workers. Current guidelines may also contradict fatigue management advice (e.g. advising against daytime napping). The present study utilized a Delphi methodology to determine expert opinion regarding the applicability of current guidelines for shift workers, the appropriateness of the term "sleep hygiene," and develop tailored guidelines for shift workers.

METHODS

The research team reviewed current guidelines and existing evidence to draft tailored guidelines. Seventeen individual guidelines, covering sleep scheduling, napping, sleep environment, bedtime routine, substances, light exposure, diet, and exercise were drafted. Experts from sleep, shift work, and occupational health fields (n = 155) were invited to review the draft guidelines using a Delphi methodology. In each round, experts voted on individual guidelines, with 70% agreement considered consensus. Where consensus was not reached, written feedback from experts was discussed and incorporated into subsequent iterations.

RESULTS

Of the experts invited, 68 (44%) agreed to participate, with 55 (35%) completing the third (final) round. Most experts (84%) agreed that tailored guidelines were required for shift workers. Consensus was reached on all guidelines after three rounds. One additional guideline (sleep inertia) and an introductory statement were developed, resulting in a final set of 18 individual guidelines, termed "healthy sleep practices for shift workers."

CONCLUSIONS

This is the first study to develop tailored sleep hygiene guidelines for shift workers. Future research should investigate the acceptability and effectiveness of these guidelines amongst shift workers.

Children with Autism Spectrum Disorder Exhibit Elevated Physical Activity and Reduced Sedentary Behavior

According to previous research, individuals with autism spectrum disorder (ASD) have lower levels of physical activity than their typically developed (TD) counterparts. There have been conflicting reports about physical activity (PA) levels in people with ASD. Given the conflicting evidence, further investigation is required. We believe that evaluating PA in individuals with ASD is critical in order to offer PA intervention plans aiming at increasing their health-related physical fitness on a daily, systematic, and individualized basis. In the current study, an ActiGraph monitor (GT3X+) was used to accurately measure PA and sedentary activity in 21 children with autism aged 6.43 ± 2.29 years and 30 TD children aged 7.2 ± 3.14 years. Our data indicated that while the light and moderate activity counts were not significantly different between the two groups, the vigorous activity was significantly higher in ASD compared to TD. This finding was attributed to ASD characteristic stereotypy and self-stimulating behaviors. The significantly higher vigorous PA is discussed in relation to altered neurochemistry, oxidative stress, and neuroinflammation as etiological mechanisms in ASD. This research provides a better understanding of the status of PA participation in individuals with ASD.

Recovery from shift work

One fifth of today's workforce is engaged in shift work and exposed to various mental and physical health risks including shift work disorder. Efficiently recovering from shift work through physical and mental interventions allows us to mitigate negative effects on health, enables a better work-life balance and enhances our overall wellbeing. The aim of this review is to provide a state-of-the-art overview of the available literature. The role of sleep timing and naps, light therapy and psychotherapy, diet and exercise in recovery from shift work is presented here. We further review the impact of shift schedules and social support on post-shift unwinding.

Exogenous Ketosis Improves Sleep Efficiency and Counteracts the Decline in REM Sleep after Strenuous Exercise

INTRODUCTION

Available evidence indicates that ketone bodies may improve sleep quality. Therefore, we determined whether ketone ester (KE) intake could counteract sleep disruptions induced by strenuous exercise.

METHODS

Ten well-trained cyclists with good sleep quality participated in a randomized crossover design consisting of two experimental sessions each involving a morning endurance training and an evening high-intensity interval training ending 1 h before sleep, after which polysomnography was performed overnight. Postexercise and 30 min before sleeping time, subjects received either 25 g of KE (EX KE ) or a placebo drink (EX CON ). A third session without exercise but with placebo supplements (R CON ) was added to evaluate the effect of exercise per se on sleep.

RESULTS

Blood d -β-hydroxybutyrate concentrations transiently increased to ~3 mM postexercise and during the first part of the night in EX KE but not in EX CON or R CON . Exercise significantly reduced rapid eye movement sleep by 26% ( P = 0.001 vs R CON ) and increased wakefulness after sleep onset by 95% ( P = 0.004 vs R CON ). Interestingly, KE improved sleep efficiency by 3% ( P = 0.040 vs EX CON ) and counteracted the exercise-induced decrease in rapid eye movement sleep ( P = 0.011 vs EX CON ) and the increase in wakefulness after sleep onset ( P = 0.009 vs EX CON ). This was accompanied by a KE-induced increase in dopamine excretion ( P = 0.033 vs EX CON ), which plays a pivotal role in sleep regulation. In addition, exercise increased sleep spindle density by 36% ( P = 0.005 vs R CON ), suggesting an effect on neural plasticity processes during sleep.

CONCLUSIONS

These data indicate that KE ingestion improves sleep efficiency and quality after high-intensity exercise. We provide preliminary evidence that this might result from KE-induced increases in dopamine signaling.

Protocol of the Budapest sleep, experiences, and traits study: An accessible resource for understanding associations between daily experiences, individual differences, and objectively measured sleep

Sleep is both a neurophysiological state and a biologically necessary behavior that performs a variety of indispensable roles for human health, development, and cognitive functioning. Despite this, comparatively little is known about the relationships between daily experiences and sleep features. Importantly, these relationships are bidirectional in nature, may be differently associated with subjectively and objectively assessed sleep, and may also be modulated by individual differences To address this challenge, we created the Budapest Sleep, Experiences, and Traits Study (BSETS), a multidisciplinary observational sleep study utilizing novel remote EEG devices. BSETS was designed to establish a dataset for future use in investigating the relationships between sleep features and daily experiences. In this paper we describe the protocol of the currently ongoing BSETS, which examines a community-dwelling sample of over 250 healthy participants who are studied in a naturalistic setting using a large questionnaire assessing psychological, demographic, and anthropometric information, as well as evening/morning diaries of sleep and daily experiences, and mobile EEG recordings over a period of 7 days. This dataset will become an accessible resource to the wider scientific community and can be utilized to investigate the complex multidirectional relationships between objectively and subjectively measured sleep, daily experiences, and individual differences, bestowing it with significant value for sleep researchers as well as practitioners working in clinical settings with patients suffering from disordered sleep.

Activities and social contact as antecedents to sleep onset time in U.S. adolescents

This study evaluated adolescents' evening patterns in activities, social contact, and location to better understand antecedents to adolescents' sleep onset time (SOT). The SOT is important for sleep duration and related health outcomes. Using a nationally representative sample of 15- to 18-year-old adolescents from the American Time Use Survey (N = 10,341; 47% female; 57% white), structural equation modeling demonstrated that late SOTs mediated links between evening activities, social contact, locations, and shorter sleep durations. Passive leisure, time in public locations, and time with friends late in the evenings were associated with later SOTs, whereas homework and active leisure did not. Parents and practitioners can use this information to carefully evaluate evening activities, social contact, and location to support healthy SOTs for adolescents across time.

Soccer, Sleep, Repeat: Effects of Training Characteristics on Sleep Quantity and Sleep Architecture

Due to the high demands of competitive sports, the sleep architecture of adolescent athletes may be influenced by their regular training. To date, there is no clear evidence on how training characteristics (intensity, time of day, number of sessions) influence sleep quality and quantity. 53 male soccer players (M = 14.36 years, SD = 0.55) of Austrian U15 (n = 45) and U16 elite teams (n = 8) were tested on at least three consecutive days following their habitual training schedules. Participants completed daily sleep protocols (7 a.m., 8 p.m.) and questionnaires assessing sleep quality (PSQI), chronotype (D-MEQ), competition anxiety (WAI-T), and stress/recovery (RESTQ). Electrocardiography (ECG) and actigraphy devices measured sleep. Using sleep protocols and an ECG-based multi-resolution convolutional neural network (MCNN), we found that higher training intensity leads to more wake time, that later training causes longer sleep duration, and that one training session per day was most advantageous for sleep quality. In addition, somatic complaints assessed by the WAI-T negatively affected adolescent athletes' sleep. Individual training loads and longer recovery times after late training sessions during the day should be considered in training schedules, especially for adolescent athletes. MCNN modeling based on ECG data seems promising for efficient sleep analysis in athletes.

Acute evening high-intensity interval training may attenuate the detrimental effects of sleep restriction on long-term declarative memory

Recent evidence shows that a nap and acute exercise synergistically enhanced memory. Additionally, human-based cross-sectional studies and animal experiments suggest that physical exercise may mitigate the cognitive impairments of poor sleep quality and sleep restriction, respectively. We evaluated whether acute exercise may offset sleep restriction's impairment of long-term declarative memory compared to average sleep alone. A total of 92 (82% females) healthy young adults (24.6 ± 4.2 years) were randomly allocated to one of four evening groups: sleep restriction only (S5, 5-6 h/night), average sleep only (S8, 8-9 h/night), high-intensity interval training (HIIT) before restricted sleep (HIITS5), or HIIT before average sleep (HIITS8). Groups either followed a 15-min remote HIIT video or rest period in the evening (7:00 p.m.) prior to encoding 80 face-name pairs. Participants completed an immediate retrieval task in the evening. The next morning a delayed retrieval task was given after their subjectively documented sleep opportunities. Long-term declarative memory performance was assessed with the discriminability index (d') during the recall tasks. While our results showed that the d' of S8 (0.58 ± 1.37) was not significantly different from those of HIITS5 (-0.03 ± 1.64, p = 0.176) and HIITS8 (-0.20 ± 1.28, p = 0.092), there was a difference in d' compared to S5 (-0.35 ± 1.64, p = 0.038) at the delayed retrieval. These results suggest that the acute evening HIIT partially reduced the detrimental effects of sleep restriction on long-term declarative memory.

Effect of Nighttime Exercise on Sleep Quality Among the General Population in Riyadh, Saudi Arabia: A Cross-Sectional Study

Introduction Engaging in physical activity has been proven to have health benefits, with a positive impact on sleep quality. While the timing of exercise plays a significant role in determining its effect on sleep, nighttime exercise still needs to be explored, especially in Saudi Arabia. This study assessed the effect of nighttime exercise on sleep quality among the general population in Riyadh, Saudi Arabia. Methods A cross-sectional study was conducted on people performing physical exercises in the gym, training, and walking places using a self-administered questionnaire evaluating exercising behaviors and sleep quality. Comparisons were performed using the Chi-square test and ANOVA, and p<0.05 was considered for significance. Results We enrolled 385 participants, among whom 53.8% were male, and 47.2% were female. The mean age was 28.2±7.85 years, and mostly aged 25-29 years (24.7%), followed by 20-24 years old (21.3%). Most had university degrees (61.3%) and were also employed (60%). Of all participants, the majority were overweight and obese (61.3%). Most (n=225) participants practiced vigorous physical exercise, and the mean Pittsburgh Sleep Quality Index (PSQI) global score was 7.37±3.49 points. Evening vigorous (r= 0.25, p=0.038) and moderate (r=0.30, p=0.025) physical exercise sessions lasting > 90 min had a significant positive correlation with poor sleep quality (high PSQL score). There was no statistically significant correlation between sleep quality and other variables (p>0.05). Conclusion This study found that participants had poor sleep quality, and lengthy, intense evening exercises had a negative effect on sleep. Incorporating regular exercise tailored to individual preferences and encouraging people to widen the time interval between exercise and bedtime could improve sleep quality.

Would the Actigraph Always be Sufficient for Sleep Analysis in Exercise-Based Studies? A Case Report of Negative Response of Sleep to Exercise

Introduction  Sleep deprivation is common after coronary artery bypass grafting (CABG). It is mostly managed well by exercise. The number of reported post-CABG cases that respond negatively to exercise is scanty. The etiology is usually associated with the underlying sleep pathology, and how it responds to exercise. Cases with undiagnosed central sleep apnea post CABG have not been reported before. Case description  A medically stable male patient, 63 years old, hypertensive, but not diabetic, had entered coronary artery bypass grafting (CABG) 8 weeks before attending the outpatient cardiac rehabilitation unit and was referred for a cardiac rehabilitation program at this time. He entered a study in the cardiac rehabilitation center utilizing either aerobic or combined aerobic and resistance training for 10 weeks to improve sleep architecture and functional capacity post-CABG. After randomization, he entered the group doing combined aerobic and resistance exercises. All of the patients in this group improved except him, his sleep quality worsened, but his functional capacity improved. After a complete analysis of sleep on polysomnography, it was revealed that the patient had central sleep apnea that was mostly worsened by resistance training. The patient was withdrawn from the study by the 8th week, and his sleep condition improved gradually. After then, he was asked to attend the cardiac rehabilitation center again to share in aerobic exercise, having evidence that central sleep apnea does not respond negatively to this form of training. After 12 months of follow-up, the patient still shows no signs of sleep deprivation. Conclusion  Sleep deprivation is prevalent in post-CABG patients, but with different presentations and it can generally improve by exercise. Identification of the underlying cause of the sleeping difficulty is a cornerstone of targeted treatment.

Habitual sleep and intraindividual variability of sleep in gifted children: an actigraphy study

STUDY OBJECTIVES

Giftedness is a multidimensional condition. It is increasingly put forward that gifted children (GC) could be a population at high risk for sleep problems. The current study investigated GC and typically developing children for their habitual sleep, night-to-night sleep variability, and parental reports of child sleep.

METHODS

The sample consisted of 62 GC (31 girls; mean age = 9.63 ± 1.71 years) and 62 typically developing children (31 girls; mean age = 9.68 ± 1.68 years). Groups were age and sex matched. Giftedness was identified using Renzulli's 3-factor definition of giftedness. Sleep duration, quality, and night-to-night variability were assessed using actigraphy. Parents were asked to complete the short-form version of the Children's Sleep Habits Questionnaire to report on their child's sleep. Groups were compared with independent sample t-tests and chi-square analyses.

RESULTS

GC displayed lower sleep efficiencies, more wake time after sleep onset, and more night-to-night sleep variability than typically developing children. GC were found to experience less social jetlag compared to typically developing children, and they also showed more clinically significant sleep problems as reported by parents.

CONCLUSIONS

Sleep maintenance and stability tend to be challenged in GC. While there is growing evidence that greater sleep variability is associated with poorer physical and emotional health, studies have yet to examine these associations in GC specifically to get a better understanding of giftedness. Overall, there is a need for research focused on both predictors and consequences of sleep patterns and sleep variability in GC.

CITATION

Bastien L, Théoret R, Bernier A, Godbout R. Habitual sleep and intraindividual variability of sleep in gifted children: an actigraphy study. J Clin Sleep Med. 2023;19(5):925-934.

Association of the time of day of peak physical activity with cardiovascular mortality: Findings from the UK Biobank study

Cardiovascular physiology and pathophysiology display pronounced circadian rhythms. The study is designed to examine whether the time of day of physical activity is associated with cardiovascular mortality. We analyzed 94,489 UK Biobank adults with objectively measured physical activity, including 53,328 morning-type participants and 30,962 evening-type participants based on self-reported chronotypes. The time of day of peak physical activity was categorized using a machine learning algorithm: early morning (n = 18,477), late morning (n = 25,700), midday (reference) (n = 27,803), and night (n = 22,509). Hazard ratios of cardiovascular mortality were examined using the Cox proportional hazards model. During a median follow-up of 6.9 years (interquartile range, 6.3-7.4 years), we identified 629 cardiovascular deaths. The hazard of cardiovascular mortality was elevated in the early morning group (hazard ratio = 1.56, 95% Confidence Interval [1.23-1.98]) and night group (1.49, [1.18-1.88]) but not in the late morning group (1.21, [0.98-1.47]) compared to the referent midday group. In the chronotype-stratified analysis, the increased cardiovascular mortality in the morning group was only observed in the evening-type participants, while the increased cardiovascular mortality in the night group was only observed in the morning-type participants. In conclusion, optimizing the timing of peak physical activity according to cardiovascular circadian rhythms and individual chronotypes could be a potential therapeutic target that brings additional health benefits.

Sleep hygiene strategies for individuals with chronic pain: a scoping review

OBJECTIVES

Up to a quarter of the world's population experience chronic pain, which, in addition to interfering with daily activities and waking function, is often associated with poor sleep. Individuals experiencing poor sleep are often encouraged to implement sleep hygiene strategies. However, current sleep hygiene strategies have not been developed considering the unique challenges faced by individuals with chronic pain and therefore they might not be as effective in this population. The aim of this scoping review is to map the state of the existing literature examining sleep hygiene strategies in individuals with chronic pain.

DESIGN

This scoping review included a search of four online databases (Medline, Embase, PsycINFO and CINAHL) to identify articles examining the use of sleep hygiene strategies in populations with chronic pain.

RESULTS

Thirty articles investigated at least one sleep hygiene strategy in individuals with chronic pain, with improvements to sleep reported for six sleep hygiene strategies (education, exercise, limiting alcohol use, limiting tobacco use, prebed state and sleep environment). However, the timing of these strategies was often not reported which limits the degree to which these strategies can be generalised for use as a presleep strategy.

CONCLUSION

This scoping review examined the existing literature focusing on sleep hygiene strategies for people with chronic pain. There are limitations to the methodology of the existing literature and gaps in our understanding of sleep hygiene strategies in some chronic pain conditions that must be addressed in future research before the effectiveness of these strategies can be understood.

Bidirectional Daily Associations Between Accelerometer-Measured Sleep and Physical Activity in Brazilian High School Students

PURPOSE

This study analyzed day-to-day estimates of bidirectional associations between sleep parameters and intensity-specific physical activity and assessed whether the timing of physical activity influences these relationships.

METHODS

The sample was comprised of 651 high school students (51.2% female, 16.33 [1.0] y old) from southern Brazil. Physical activity and sleep were measured using accelerometers. Multilevel models were applied to test associations of nocturnal total sleep time, onset, and efficiency with moderate to vigorous and light (LPA) physical activity.

RESULTS

Higher engagement in moderate to vigorous physical activity and LPA was associated with increased total sleep time, and this effect was greater when physical activity was performed in the morning. Morning and evening LPA were associated with increased sleep efficiency and reduced total sleep time, respectively. Practice of LPA in the morning leads to early sleep onset, whereas evening LPA was associated with later onset. Higher total sleep time and later sleep onset were associated with lower moderate to vigorous physical activity and LPA on the following day. However, higher sleep efficiency was associated with increased LPA.

CONCLUSION

The relationship between sleep parameters and physical activity is bidirectional and dependent on physical activity intensity and timing.

The Influence of Light and Physical Activity on the Timing and Duration of Sleep: Insights from a Natural Model of Dance Training in Shifts

Environmental, social, and behavioral variables influence sleep timing and duration. Using wrist-worn accelerometers, we recorded 31 dancers (age = 22.6 ± 3.5) for 17 days and who trained either in the morning (n = 15) or in the late evening (n = 16). We estimated the dancers' daily sleep pattern: onset, end, and duration. In addition, their minutes of moderate-to-vigorous physical activity (MVPA) and mean light illuminance were also calculated daily and for the morning-shift and late-evening-shift time windows. On training days, the shifts involved differences in sleep timing, alarm-driven waking frequency, and the pattern of light exposure and MVPA duration. Sleep was strongly advanced when dancers trained in the morning and when alarms were used, while morning light had a low influence. Sleep was delayed when dancers were more exposed to light and displayed longer MVPA during the late evening. Sleep duration was strongly reduced on weekends and when alarms were used. A small reduction in sleep duration was also observed when morning illuminance was lower or when late evening MVPA was longer. Training in shifts influenced the timing of environmental and behavioral factors, which added up to shape dancers' sleep timing and duration.

The effect of acute exercise on the cortisol awakening response

The effects of acute exercise on the cortisol awakening response (CAR), characterized by the rapid increase in cortisol concentrations within the 30-45 min following sleep offset has yet to be fully elucidated. Thus, our study investigated the effects of late-evening acute exercise on the CAR the following morning. We hypothesized that exercise would have a significant effect on the CAR the following morning. Twelve participants (mean (SD): age = 23 (4) years; mass = 76.8 (8.7) kg; height = 175.6 (5.0) cm; [Formula: see text]O2max = 48.9 (7.5) ml.kg^-1.min^-1) reported to the laboratory in the evening (1800 h) on two occasions and were randomly assigned to either exercise for one hour (70-75% of maximal power output) or rest condition. Blood and saliva samples were assayed for cortisol. Mixed-effects models determined the effect of exercise on the cortisol response post-waking in both blood and saliva. Participants demonstrated an average exercise-induced increase in circulating cortisol of 477.3%, with actual mean (SD) heart rate relative to maximum of 87.04% (6.14%). Model results demonstrated a negative effect for exercise condition when modeling the serum and salivary cortisol responses to awakening via a quadratic growth model (serum, β_Condition = - 42.26 [95% CI - 64.52 to - 20.01], p < 0.001; saliva, β_Condition = - 11.55 [95% CI - 15.52 to - 7.57], p < 0.001). These results suggest that cortisol concentrations in saliva and blood are significantly lower the morning following a prior evening exercise session. Therefore, the CAR may serve as a useful biomarker to monitor responses to exercise training, although the underlying mechanism for these decreases in the CAR should be investigated further.

Intraday adaptation to extreme temperatures in outdoor activity

Linkages between climate and human activity are often calibrated at daily or monthly resolutions, which lacks the granularity to observe intraday adaptation behaviors. Ignoring this adaptation margin could mischaracterize the health consequences of future climate change. Here, we construct an hourly outdoor leisure activity database using billions of cell phone location requests in 10,499 parks in 2017 all over China to investigate the within-day outdoor activity rhythm. We find that hourly temperatures above 30 °C and 35 °C depress outdoor leisure activities by 5% (95% confidence interval, CI 3-7%) and by 13% (95% CI 10-16%) respectively. This activity-depressing effect is larger than previous daily or monthly studies due to intraday activity substitution from noon and afternoon to morning and evening. Intraday adaptation is larger for locations and dates with time flexibility, for individuals more frequently exposed to heat, and for parks situated in urban areas. Such within-day adaptation substantially reduces heat exposure, yet it also delays the active time at night by about half an hour, with potential side effect on sleep quality. Combining empirical estimates with outputs from downscaled climate models, we show that unmitigated climate change will generate sizable activity-depressing and activity-delaying effects in summer when projected on an hourly resolution. Our findings call for more attention in leveraging real-time activity data to understand intraday adaptation behaviors and their associated health consequences in climate change research.

Physical Activity Levels and Sleep in Schoolchildren (6-17) with and without School Sport

There is strong evidence to support the association between daily physical activity and sleep parameters in children and adolescents. Physical activity and outdoor play are favourably associated with most sleep outcomes in school children. The aim is to find out the levels of physical activity and the quality of sleep in Basque schoolchildren aged between six and seventeen and to analyse the possible differences between those who carry out some kind of physical sports activity and those who do not. The sample consisted of 1082 schoolchildren (50.1% male and 49.9% female). Differences between groups were compared using the Mann-Whitney U test (2 samples) and Kruskal-Wallis one-factor ANOVA (k samples). A total of 723 (66.94%) of the participants said they practiced some physical sports activity. The accelerometers obtained significant differences in all levels of physical activity, as well as in sleep efficiency, with higher levels of physical activity (sedentary p = 0.001; light p = 0.017; moderate p = 0.009; vigorous p = 0.001 and moderate-to-vigorous physical activity p = 0.002) and better sleep efficiency (p = 0.002) in those schoolchildren who perform some type of physical sports activity. A significant difference in time spent in sedentary activities was also observed between primary and secondary school pupils of both sexes and regardless of the degree of physical sports activity completion.

Possible effects of uberization on the quality of sleep of professional drivers

Uber and other on-demand business platforms drivers experience unparalleled flexibility in work hours, and many are using this model instead of working a fixed-hours job. The option of working more hours a day and, as a result, increasing the remuneration received is often chosen by drivers even at the expense of sleep. Due to their professional obligation, this population is at risk of excessive sleepiness due to sleep deprivation or poor sleep quality, increasing the risk of detrimental effects on health and the risk of car accidents. Considering that sleep is essential for general health, it is mandatory to create strategies to address these issues, such as limiting the maximum number of hours worked a day under the laws regulating labor rights and periodically assessing drivers' alertness.

Determinants of natural adult sleep: An umbrella review

BACKGROUND

Sleep has a major impact on health, which makes it a relevant topic for research and health practitioners. Research on sleep determinants, i.e. factors that positively or negatively influence sleep, is fragmented.

OBJECTIVE

The purpose of this umbrella review is to provide an overview of the current evidence on determinants of natural adult sleep.

METHODS

A comprehensive literature search was performed on determinants of sleep. Reviews and meta-analyses on natural adult sleep were included. Six electronic databases (PubMed, WoS, Embase, CINAHL, PsycInfo and Cochrane) were used for the search, last accessed September 2021. The quality of the selected articles was assessed using the AMSTAR2 tool. Results were categorized in four main categories: biological, behavioral, environmental and personal/socio-economical determinants.

RESULTS

In total 93 reviews and meta-analyses resulted in a total of 30 identified determinants. The impact of each determinant differs per individual and per situation. Each determinant was found to affect different sleep parameters and the relationship with sleep is influenced by both generic and specific moderators.

DISCUSSION

A comprehensive overview on relevant sleep determinants provides a practical and scientifically based starting point to identify relevant intervention approaches to secure or improve individual sleep quality. The difference in aggregation level of the determinants and in measurement methods are the major limitations of this umbrella review. Extending existing generic sleep hygiene rules with an overview of all types of potential determinants will enhance the awareness of the complexity and can be used to improve the effect of sleep interventions in health promotion.

TRIAL REGISTRATION

The umbrella review was registered with PROSPERO (registration ID CRD42020149648) https://www.google.com/search?client=firefox-b-d&q=CRD42020149648.

Bidirectional associations between physical activity and sleep in older adults: a multilevel analysis using polysomnography

Although recent studies have examined the bidirectional associations between physical activity and sleep parameters, few have focused on older adults utilizing objective assessments, such as polysomnography. This micro-longitudinal observational study included 92 Japanese older adults (aged 65–86 years) who underwent objective evaluations of sleep quality using polysomnography and completed subjective sleep-related questionnaires. Activity levels were assessed using an accelerometer. Polysomnography, subjective sleep-related questionnaires, and accelerometer were administered for 7 consecutive days. Multilevel models (participant-, day-level) were used to examine the temporal associations of objective and subjective sleep parameters with sedentary behavior and physical activity. In the day-level analysis, higher levels of sedentary behavior during daytime were associated with longer rapid eye movement (REM) sleep, shorter REM latency, lower levels of non-REM sleep (stage N3), and reduced delta power during daytime. Higher levels of low-intensity physical activity during daytime were associated with lower levels of REM sleep, longer REM latency, and increased stage N3 sleep in the day-level analysis. Higher levels of moderate-to-vigorous physical activity were associated with increased REM latency. Longer subjective sleep time was associated with increased next-day moderate-to-vigorous physical activity. Thus, low-intensity physical activity may provide objective benefits related to deep sleep parameters in older adults.

Short-term effect of physical activity on sleep health: A population-based study using accelerometry

BACKGROUND

Regular physical activity (PA) is an important behavior in improving sleep health. However, the short-term effects of PA on sleep are still controversial. This study aimed to verify the effect of different intensities of PA practiced in different periods of the day on the subsequent sleep night in a population-based cohort of young adults.

METHODS

Prospective analyses were conducted for PA performed during the day and its effect on the following sleep night using data from the 22-year follow-up of the 1993 Pelotas Birth Cohort in Brazil (mean age of participants = 22.6 years). Wrist-worn accelerometry was used to measure both PA and sleep parameters. Regarding intensity, we analyzed the sleep effect of light PA (LPA), moderate PA, and vigorous PA, stratified by sex. Sleep variables were sleep time window (STW; the difference between sleep onset and sleep end), total sleep time (TST; the sum of minutes classified as sleep in STW), and sleep percent (SP; SP = (TST/STW); expressed in percentage). We performed generalized estimating equations using Stata software.

RESULTS

The means of STW, TST, and SP were 443.6 min/day, 371.1 min/day, and 84%, respectively. Time spent in moderate PA and vigorous PA in the morning and afternoon was not associated with sleep variables. Among men, 10 min/day of morning LPA increased TST by 2.56 min/day. Among women, 10 min/day of morning LPA increased SP by 0.15 percentage points. Afternoon LPA also increased SP by 0.09 percentage points for women. Night PA seems to have an inverse effect on sleep variables for any intensity and both sexes.

CONCLUSION

The effect of PA on sleep health is intrinsically related to the period of the day in which it is performed. The effect magnitude is different between sexes. For better sleep health, it is preferable that PA be performed during the day.

A Review of Equine Sleep: Implications for Equine Welfare

Sleep is a significant biological requirement for all living mammals due to its restorative properties and its cognitive role in memory consolidation. Sleep is ubiquitous amongst all mammals but sleep profiles differ between species dependent upon a range of biological and environmental factors. Given the functional importance of sleep, it is important to understand these differences in order to ensure good physical and psychological wellbeing for domesticated animals. This review focuses specifically on the domestic horse and aims to consolidate current information on equine sleep, in relation to other species, in order to (a) identify both quantitatively and qualitatively what constitutes normal sleep in the horse, (b) identify optimal methods to measure equine sleep (logistically and in terms of accuracy), (c) determine whether changes in equine sleep quantity and quality reflect changes in the animal's welfare, and (d) recognize the primary factors that affect the quantity and quality of equine sleep. The review then discusses gaps in current knowledge and uses this information to identify and set the direction of future equine sleep research with the ultimate aim of improving equine performance and welfare. The conclusions from this review are also contextualized within the current discussions around the “social license” of horse use from a welfare perspective.

Combining Cognitive Behavioral Therapy for Insomnia and Chronic Spinal Pain Within Physical Therapy: A Practical Guide for the Implementation of an Integrated Approach

Most people who have nonspecific chronic spinal pain (nCSP) report comorbid insomnia. However, in current treatment strategies for nCSP, insomnia is usually not addressed. Considering the bidirectional interaction between pain and sleep and its underlying psychophysiological mechanisms, insomnia may increase the risk of developing adverse physical and psychological health outcomes and should thus no longer be left untreated. As suggested by previous pilot studies, adding cognitive behavioral therapy for insomnia to the contemporary evidence-based biopsychosocial physical therapy approach may also improve pain outcomes in nCSP. This manuscript aims to provide practical guidelines on hybrid physical therapy, including the combination of the following components: (1) pain neuroscience education (eg, to reconceptualize pain) and cognition-targeted exercise therapy (eg, graded exposure to functional daily life movements), and (2) cognitive behavioral therapy for insomnia (sleep psychoeducation, behavioral and cognitive therapy, correction of sleep hygiene, and relaxation therapy) can be deployed for the management of patients who have chronic spinal pain. Impact. Due to the major impact sleep disturbances have on pain and disability, insomnia as a comorbidity should no longer be ignored when treating patients with chronic spinal pain.

Actigraphic Physical Activity, Pain Intensity, and Polysomnographic Sleep in Fibromyalgia

INTRODUCTION

Fibromyalgia involves chronic pain and disrupted physical activity and sleep. Research examining the relationship between pre-bedtime physical activity, pain, and objective sleep is limited. This study examined whether objectively measured physical activity levels (via actigraphy), pain intensity, or their interaction are associated with polysomnographic sleep outcomes.

METHODS

Adults with fibromyalgia and insomnia complaints (n = 134, mean age = 52 yrs, SD = 12 yrs, 94% female) completed 14 days of biaxial, wrist worn actigraphy, pain ratings, and a single night of polysomnography (PSG). Average activity for intervals 9:00-12:00, 12:00-15:00, 15:00-18:00, 18:00-21:00 was computed. Multiple regressions examined whether average activity, average evening pain, or their interaction were associated with PSG outcomes: sleep onset latency (SOL), wake after sleep onset (WASO), sleep efficiency, %stage1, %stage2, %stage3, and %rapid eye movement. Analyses controlled for age, body mass index, average bedtime, time in bed, and sleep/pain medication use.

RESULTS

Greater morning actigraphic physical activity from 9:00 to 12:00 was independently associated with greater %stage 1 sleep (B = 0.01, SE = 0.00, p < .01). Greater afternoon activity from 12:00 to 15:00 independently predicted a higher WASO (p < .001). Associations between afternoon physical activity from 12:00 to 15:00 and greater %stage 1 (p < .001) were significant for at higher (~71/100), average (~52/100), but not lowest (~32/100) pain.

CONCLUSION

Greater morning and afternoon activity is associated with greater PSG sleep fragmentation and greater %stage 1 sleep in individuals with fibromyalgia and insomnia complaints, and the relationship between higher physical activity and greater %stage 1 is stronger for individuals with higher pain. Further studies examining causal pathways between physical activity, activity pacing, and sleep are warranted in fibromyalgia.

A network meta-analysis comparing the effects of exercise and cognitive training on executive function in young and middle-aged adults

AbstractIn young and middle-aged adults, executive function is associated with success in work-life and mental health. Physical activity with and without cognitive training has the potential to benefit executive function, but its relative effectiveness remains unclear. This network meta-analysis compares the effectiveness of different exercise and cognitive training types and their combination on executive function in young and middle-aged adults. PubMed, Web of Science, MEDLINE, Cochrane, PsycINFO, and SPORTDiscus were searched for experimental studies that compared pre- to posttest changes in inhibitory control and/ or working memory between one or more intervention groups and a control group. Interventions were ranked on their relative effectiveness using P-scores. Study quality was rated using the PEDro scale. Forty-six studies were included and yielded 30 and 70 pair-wise effect sizes for the inhibitory control and working memory networks, respectively. With one exception, all studies were of high quality. Combined exercise and working memory training induced the greatest benefits for working memory (standardized mean differences, SMD = 0.59), whereas training a single executive function (SMD = 0.32) was most effective for inhibitory control. The effectiveness of working memory training (SMD ≥ 0.27) and coordinative exercise (SMD ≥ 0.20 to 0.29) ranked second and third for both executive function outcomes. In contrast, the effectiveness of endurance exercise was comparable to active controls on both networks. In young and middle-aged adults, exercise with coordinative demands seems to have an effectiveness similar to working memory training. The combination of exercise and cognitive training further increases executive function benefits.

Sleep and physical activity: results from a long-term actigraphy study in adolescents

PURPOSE

Research to date suggests that physical activity is associated with improved sleep, but studies have predominantly relied on self-report measures and have not accounted for school day/free day variability. To address these gaps in the literature, the aim of the present study was to (a) quantify physical activity in adolescents using long-term daily actigraphy measurement and (b) to examine the association between actigraphically assessed steps and sleep behavior in a sample of healthy adolescents. To be able to capture intra- and inter-individual differences in the daily physical activity of adolescents, we examined within as well as between subjects effects and its association with sleep.

METHODS

Fifty adolescents between 10 and 14 years of age were included in the present study. In total 5989 days of actigraphy measurement (average of 119 ± 40 days per participant; range = 39-195 days) were analyzed. We use multilevel modeling to disentangle the within and between subject effects of physical activity on sleep. In this way, we examine within an individual, the association between steps during the day and subsequent sleep on a day-to-day basis. On the other hand, our between subjects' analysis allows us to ascertain whether individuals with more overall physical activity have better sleep.

RESULTS

Within a subject more steps on school and free days were associated with later bed times on school and free days as well as later rise times on school days only. On the other hand, comparing between subjects' effects, more steps were associated with lower sleep efficiency on free and school days. No other significant associations were found for the other sleep variables.

CONCLUSION

Our results obtained through objective and long-term measurement of both sleep and number of steps suggest weak or non-significant associations between these measures for most sleep variables. We emphasize the importance of the methodology and the separation of within subject from between subject features when examining the relationship between physical activity and sleep.

Nocturnal Lifestyle Behaviours and Risk of Poor Sleep during Pregnancy

The extent to which lifestyle practices at night influence sleep quality in pregnant women remains unknown. This study aimed to examine whether nocturnal behaviours were associated with poor sleep during pregnancy. We performed a cross-sectional analysis of a prospective cohort of pregnant women at 18–24 gestation weeks recruited from KK Women’s and Children’s Hospital, Singapore, between 2019 and 2021. Nocturnal behaviours were assessed with questionnaires, and sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI) with a global score ≥5 indicative of poor sleep quality. Modified Poisson regression and linear regression were used to examine the association between nocturnal behaviour and sleep quality. Of 299 women, 117 (39.1%) experienced poor sleep. In the covariate-adjusted analysis, poor sleep was observed in women with nocturnal eating (risk ratio 1.51; 95% confidence interval [CI] 1.12, 2.04) and nocturnal artificial light exposure (1.63; 1.24, 2.13). Similarly, nocturnal eating (β 0.68; 95% CI 0.03, 1.32) and light exposure (1.99; 1.04, 2.94) were associated with higher PSQI score. Nocturnal physical activity and screen viewing before bedtime were not associated with sleep quality. In conclusion, reducing nocturnal eating and light exposure at night could potentially improve sleep in pregnancy.

Technology and Sleep Quality: Friend or Foe? Let the Exergames Come into Play!

Low sleep quality is associated with many health problems. Although physical exercise is a nonpharmacological tool that positively impacts sleep quality, there are many barriers (lack of energy, lack of motivation, lack of skills, lack of resources, and fear of injury) for people to adopt an active lifestyle. Exergames are an alternative way of physical exercise that are funnier and more attractive than traditional forms of physical exercise and, therefore, has the potential to increase adherence to a physical exercise program. Given that previous studies showed that exergames presents similar physiological and psychological outcomes to traditional forms of exercise, we aimed to discuss in this narrative review potentials applications, limitations and perspectives of using exergames to improve sleep quality.