Abstract
Sleep problems constitute a significant public health issue. Previous studies have found that regular leisure-time physical activity has the potential to improve sleep quality. However, stress may influence both physical activity and sleep, acting as a potential moderator in this association. The aim was to examine cross-sectional associations between self-reported leisure-time physical activity and sleep problems, as well as the potential moderating role of stress. The study population consists of 11 346 Danish adults (age ≥16 years) from the national representative Danish Health and Morbidity Survey conducted in 2021. Associations between leisure-time physical activity and sleep problems were analysed using multiple adjusted logistic regression, which included an investigation of effect modification by level of self-perceived stress. Adjusted odds ratios (ORs) for experiencing sleep problems were 1.37 [95% confidence interval (CI): 1.20–1.56] among participants who were mainly sedentary during leisure time, and 0.81 (95% CI: 0.72–0.91) among those with moderate to vigorous physical activity level compared to those with light physical activity level. Within all strata of stress levels, higher physical activity was positively associated with lower odds of sleep problems. For example, in the high stress level stratum, ORs were 0.80 (95% CI: 0.63–1.03) and 1.64 (95% CI: 1.28–2.11) in participants who were moderately to vigorously physically active and sedentary, respectively, compared to those who were lightly physically active. Higher levels of leisure-time physical activity appear to be associated with a lower prevalence of sleep problems, even among individuals who experience high levels of stress.
Introduction
Sleep problems constitute a significant public health concern due to their association with both physical and mental health outcomes [1–3]. An increasing number of individuals report sleep problems, including sleep insufficiency and sleep disorders, demonstrating the growing need for public health attention [4–6]. Insufficient or poor quality of sleep has been linked to increased risk of chronic disease such as cardiovascular disease, obesity, diabetes, depression, heart attack, and stroke [7–9]. Beyond the increased risk of disease, sleep problems have a negative impact on cognitive performance, long-term sickness absence, and disability pension, contributing to significant societal and economic burdens [10, 11].
Previous research has found that engaging in regular physical activity can improve various aspects of sleep, such as sleepiness, insomnia, and sleep health in general [12, 13]. However, the intensity of physical activity does not appear to make a significant difference in how sleep is improved [12]. The benefits of physical activity include the ability to suppress cortisol levels at night [14], which may have a positive effect on sleep quality. Furthermore, physical activity can regulate the circadian rhythm and lower stress-related hormones, both of which are associated with improved sleep [14–16].
Stress is widely recognized as a factor that can impair sleep quality and normal sleep function, particularly among women, highly reactive sleepers, and individuals with a familial history of insomnia [17, 18]. Moreover, as reported by Kalmbach et al. [18], earlier studies have found that high sleep reactivity to stress may lead to severe insomnia phenotypes.
Research by Stults-Kolehmainen and Sinha indicates that stress negatively impacts individuals’ motivation to exercise and, therefore, reduces their engagement in physical activity and exercise [19]. Indicators of stress, such as perceived stress and life events, have been associated with decreased physical activity levels. Nevertheless, some studies also suggest that physical activity is used as a coping strategy, indicating that stress may sometimes increase physical activity [19].
While physical activity generally promotes better sleep, stress may not only impair sleep but also reduce engagement in physical activity. Despite these established individual associations, evidence on how perceived stress and physical activity interact in relation to sleep problems remains limited.
The aim of this study was to examine associations between self-reported leisure-time physical activity and sleep problems. Furthermore, the aim was to investigate the potential moderating role of stress to provide deeper insights into effective strategies for improving sleep health.
Methods
Study design and population
This population-based cross-sectional study was based on data from the National Representative Danish Health and Morbidity Survey conducted in 2021. The questionnaire survey was a part of The Danish National Health Survey, which is conducted every fourth year [20]. The design of the Danish Health and Morbidity Survey has been described elsewhere [21].
The sample for the Danish Health and Morbidity Survey was randomly selected and consisted of 25 000 Danish adults aged 16 and above. Data were collected digitally and by physical mail [21]. The total study population for the current study consisted of 11 346 individuals.
Use of data was approved according to Danish law and participants were informed that participation in the study was voluntary, and that they were guaranteed full anonymity [21].
Assessments
Self-reported sleep problems
Self-reported sleep problems were assessed using the single item question ‘Have you, within the past 14 days, experienced any sleep difficulties or sleep problems? And if yes, how bothered were you by it?’. The participant could answer ‘no’, ‘yes, slightly bothered’, and ‘yes, very bothered’. For this study, the responses ‘yes, slightly bothered’ and ‘yes, very bothered’ were combined into one category indicating sleep problems.
Self-reported level of leisure-time physical activity
Leisure-time physical activity was assessed using the self-reported Saltin and Grimby Physical Activity Level Scale [22]. The participants were asked about their typical physical activity level during leisure-time over the last 12 months. The response categories were ‘strenuous activities usually involving competition or endurance training performed regularly or several times a week’ (vigorous physical activity), ‘exercise, endurance training, or heavy gardening for at least 4 hours a week’ (moderate physical activity), ‘walking, bicycling, or other light activities for a minimum of at least 4 hours a week’ (light physical activity), and ‘reading, TV-watching, or other sedentary activities’ (sedentary).
The categorization in the analysis was based on the above-mentioned categories, except for the categories ‘vigorous physical activity’ and ‘moderate physical activity’, which were combined into one category.
Level of self-perceived stress
Self-reported stress level was measured using a Danish version of Cohen’s 10-item Perceived Stress Scale (PSS) [23]. The PSS is a self-reported measure of subjective stress and is known to be a valid and reliable instrument for measuring stress [24].
The scale consists of 10 questions in which the participants indicate how frequent they have found their life unpredictable, uncontrollable and overloaded over the past month [24]. Items are scored on a Likert scale (total sum score: 0–40), where higher scores indicate higher PSSs. No cut-off values exist, but in general, a score of 17–18 raises concern in other studies [25, 26]. Thus, self-rated stress levels in this study were divided into two categories: High stress level (PSS ≥18) and Low stress level (PSS <18).
Socioeconomic factors and other co-variates
To describe the study population, the following socio-demographic covariates were retrieved from the questionnaire: sex, age, cohabitation status, and educational level. Educational level was grouped into seven categories inspired by the Danish educational nomenclature and recoded into the following four categories of highest completed education: currently in education, primary school, lower educational level, and higher educational level [21].
The following information on health was also retrieved from the questionnaire: mental disorder defined as lasting more than 6 months (no mental disorder, current/previous mental disorder), smoking status (daily smoker/occasional smoker, ex-smoker/never smoker), and alcohol consumption, categorized as within or exceeding The Danish National Board of Health’s sensible drinking limits (≤10 units per week) [27]. Body mass index (BMI) was based on self-reported information of height and weight and classified according to WHO criteria (BMI < 25 and BMI ≥ 25) [28].
Statistical analysis
A descriptive analysis was conducted based on socioeconomic and health characteristics, stratified by sex, and included univariate comparisons of continuous and binary variables using chi-square tests. In the Supplementary Appendix, univariate comparisons were also stratified by sleep problems and physical activity levels to provide a more in-depth description of the associations.
Associations between (i) self-reported leisure-time physical activity and sleep problems and (ii) stress levels and sleep problems, were analysed using multiple adjusted logistic regression analysis. In the analysis with leisure-time physical activity as exposure, the reference group was light physical activity. This analysis was adjusted for sex, age, cohabitation status, mental disorder lasting more than six months, smoking, alcohol, education, obesity, and stress level. The analysis with PSS as the exposure variable used the group with low perceived stress level (PSS < 18) as reference category and was adjusted for sex, age, cohabitation status, mental disorder lasting more than 6 months, smoking, alcohol, education, obesity, and physical activity level. The confounders were selected based on associations documented in the literature, and significant associations with both exposure and outcome. The reference groups were chosen due to their inclusion of the largest proportion of respondents within each variable, thereby providing a stable baseline for comparison. Proportions with 95% confidence intervals (CIs) and odds ratios (ORs) were presented.
To investigate differences between participants experiencing different levels of stress, we stratified regression analyses by PSS. Interaction effects between physical activity and sex and self-reported stress levels, respectively, were tested to investigate effect modification. Separate models for each stratum were presented as OR, which were interpreted and reported as probabilities.
To explore the robustness of the results, using an alternative measure of sleep quality, we carried out a sensitivity analysis examining perceived insufficient sleep instead of sleep problems. The analysis was based on the question: ‘Do you think you get enough sleep to feel well-rested?’ and the responses were dichotomized into ‘Yes, usually’, and ‘Yes, but not enough’ vs. ‘No, never (almost never)’.
Weighting for non-response was used to make the respondent group more representative of the Danish population. The weights were based on information from administrative registers, including sex, age, municipality of residence, education level, income, marital status, ethnic background, number of visits to the general practitioner and hospitalizations within a year, occupational status, and home ownership status [21].
Analyses were performed using STATA 18.0 statistical software.
Results
The study population consisted of 4985 (44%) men and 6361 (56%) women, and the mean age was 54 years (Table 1). In total, 42% (37% men and 47% women) reported to have sleep problems while 26% (22% men and 30% women) reported a high stress level (PSS ≥ 18). During leisure time, 20% reported to engage in moderate or vigorous physical activity, 54% to be lightly active, and 17% to be sedentary.
Table 1.
Characteristics of the study population by sex (n = 11 346)a
| Variables | N | % | Men (%) | Women (%) |
|---|---|---|---|---|
| 11 346 | N = 4985 (44%) | N = 6361 (56%) | ||
| Age | ||||
| Mean age, years | 54 | – | – | – |
| 16–34 years | 2274 | 29 | 30 | 28 |
| 35–49 years | 2004 | 18 | 17 | 19 |
| 50–64 years | 3100 | 24 | 24 | 24 |
| 65+ years | 3968 | 28 | 28 | 29 |
| Education | ||||
| In education | 689 | 8 | 8 | 8 |
| Primary school | 725 | 7 | 7 | 7 |
| Lower educational level | 3607 | 31 | 33 | 29 |
| Higher educational level | 4826 | 38 | 35 | 41 |
| Missing | 1499 | 16 | 17 | 15 |
| Cohabitation status | ||||
| Lives with partner | 7552 | 59 | 61 | 56 |
| Lives alone | 3794 | 41 | 39 | 44 |
| Physical activity | ||||
| Moderate or vigorous physical activity | 2202 | 20 | 26 | 15 |
| Light physical activity | 6568 | 54 | 47 | 60 |
| Sedentary | 1770 | 17 | 17 | 17 |
| Missing | 806 | 9 | 10 | 8 |
| Smoking | ||||
| Daily smoker/occasional smoker | 1655 | 16 | 17 | 16 |
| Does not currently smoke | 9053 | 77 | 75 | 78 |
| Missing | 638 | 7 | 8 | 6 |
| Alcohol | ||||
| Consumption within alcohol limit/week | 7409 | 75 | 69 | 82 |
| Consumption above alcohol limit/week | 1764 | 15 | 20 | 9 |
| Missing (irrelevant) | 986 (1187) | 10 | 11 | 9 |
| Obesity | ||||
| BMI < 25 | 4969 | 43 | 37 | 50 |
| BMI ≥ 25 | 5414 | 46 | 57 | 40 |
| Missing | 963 | 10 | 11 | 10 |
| Sleep problems | ||||
| No problems | 5990 | 52 | 57 | 48 |
| Problems | 4825 | 42 | 37 | 47 |
| Missing | 531 | 6 | 7 | 5 |
| Stress level (PSS) | ||||
| Stress level ≥ 18 at PSS | 2661 | 26 | 22 | 30 |
| Stress level < 18 at PSS | 7976 | 67 | 71 | 63 |
| Missing | 709 | 7 | 7 | 7 |
| Mental disorder for more than 6 months | ||||
| No mental disorder | 9230 | 79 | 82 | 76 |
| Do have or have had MD | 1206 | 12 | 9 | 15 |
| Missing | 910 | 9 | 9 | 9 |
Numbers and weighted %.
Participant characteristics, stratified by sleep problems and physical activity level, are presented in Supplementary Appendices A and B. Overall, participants without sleep problems reported lower stress levels, and higher levels of leisure-time physical activity were associated with fewer sleep problems as well as lower stress prevalence. For instance, among those with moderate or vigorous physical activity levels, 31% of men and 41% of women reported sleep problems, compared to 51% and 62% among sedentary men and women. Similarly, high stress levels (PSS ≥ 18) were reported by 15% of moderately or vigorously physically active men and 26% of women, vs. 33% and 46% among sedentary men and women.
Unadjusted and adjusted associations between leisure-time physical activity and sleep problems are presented in Table 2. After adjusting for confounders, participants engaging in moderate or vigorous levels of physical activity had lower odds of experiencing sleep problems (OR = 0.81, 95% CI: 0.72–0.91) compared to those with light physical activity levels. Additionally, the OR for having sleep problems among participants who were mainly sedentary in leisure time was 1.37 (CI: 1.20; 1.56), compared to those with light physical activity levels. The association between stress level and sleep problems is also shown in Table 2. Compared to a low stress level, those with a high stress level had an OR of 3.43 (CI: 3.06; 3.83), indicating an increased risk of experiencing sleep problems.
Table 2.
Weighted unadjusted and adjusted ORs of sleep problems by leisure-time physical activity and PSS.
| Sleep problems |
|||||||
|---|---|---|---|---|---|---|---|
| Unadjusted |
Adjusted |
||||||
| % with sleep problems | Odds ratio | (95% CI) | P | Odds ratio | (95% CI) | P | |
| Leisure time physical activity level | |||||||
| Moderate or vigorous physical activity | 35 | 0.68 | (0.61; 0.75) | <.001 | 0.81 | (0.72; 0.91) | <.001 |
| Light physical activity | 45 | 1 (Ref.) | 1 (Ref.) | ||||
| Sedentary | 58 | 1.69 | (1.52; 1.87) | <.001 | 1.37 | (1.20; 1.56) | <.001 |
| Stress level by perceived stress scale | |||||||
| Stress level ≥ 18 at PSS | 67 | 3.259 | (3.28; 3.93) | <.001 | 3.43 | (3.06; 3.83) | <.001 |
| Stress level < 18 at PSS | 36 | 1 (Ref.) | 1 (Ref.) | ||||
Values are presented as percentages and weighted odds ratios. Analysis for physical activity is adjusted for sex, age, cohabitation status, mental disorder lasting more than 6 months, smoking, alcohol, education, obesity, and stress level. Analysis for stress level (PSS) is adjusted for the same covariates, with physical activity instead of stress level.
Test for interaction between physical activity and sex and self-reported stress levels, respectively, shows a statistically significant interaction, indicating that the effect of physical activity on sleep varies depending on the level of the other variables (data not shown). Figure 1 shows adjusted ORs for reporting sleep problems according to joint associations of leisure-time physical activity level and self-reported stress level. Compared to those who were lightly physically active in leisure time, engaging in moderate or vigorous physical activity was associated with a lower OR for experiencing sleep problems among participants with both high and low stress levels. Moreover, among participants with both high and low stress levels, sedentary leisure time was associated with increased odds of experiencing sleep problems. For example, among participants with sedentary leisure time and high stress level, the OR for sleep problems was 1.64 (CI: 1.28; 2.11) and among those with sedentary leisure time and a low stress level, the OR for sleep problems was 1.26 (CI: 1.08; 1.47).
Figure 1.
Weighted and adjusted odds ratios of sleep problems by leisure-time physical activity and perceived stress. Odds ratios are weighted and adjusted for sex, age, cohabitation status, mental disorder lasting more than 6 months, smoking, alcohol, education, and obesity.
Supplementary analyses show that, in the association between physical activity level and sleep problems, similar patterns were observed across sexes (Supplementary Appendix C). Finally, a sensitivity analysis using the variable ‘experienced insufficient sleep’ as a measure of sleep, confirmed that physical activity level reduces the odds of poor sleep, and the association is slightly stronger compared to sleep problems (Supplementary Appendix D).
Discussion
This study found that higher levels of physical activity in leisure time were significantly associated with a lower prevalence of self-reported sleep problems in a large, representative sample of Danish adults. Notably, the association persisted among individuals reporting high levels of stress. These findings suggest that physical activity may play a protective role in sleep regulation, potentially buffering the negative impact of psychological stress. The results point to a dynamic interaction between physical activity, stress, and sleep, underscoring the relevance of behavioural factors in mitigating stress-related sleep disturbances.
This study aligns with previous research demonstrating the beneficial effects of physical activity on sleep quality and sleep health in general [12, 13, 29, 30]. In a meta-analysis based on experimental studies, Amiri et al. [13] found that exercise improves sleep quality, reduces insomnia and sleepiness, and that providing good conditions for exercise can promote sleep health. In another meta-analysis based on experimental studies, Kredlow et al. [12] found a difference in acute and regular exercise when looking at the association with sleep problems. The findings indicate that acute exercise exerts modest positive effects on total sleep time and sleep efficiency, whereas regular exercise additionally produces moderate improvements in sleep quality.
Our study offers a different perspective than previous research by Kredlow et al. demonstrating how different intensities of physical activity influences sleep problems differently [12]. Furthermore, it adds to the current body of literature by examining the three-way interaction between physical activity, stress and sleep—a relationship that has previously received limited attention. To our knowledge, this is the first study to investigate whether stress levels moderate the association between leisure-time physical activity and sleep problems. Consistent with prior research [31], our results indicate that individuals with sedentary leisure time are more likely to report high stress levels. Research by An et al. [32] has shown that sedentary behaviour and sleep deprivation are associated with increased stress levels.
When examining the complex relationship between stress, physical activity, and sleep, the stress-buffering hypothesis proposed by Wunsch et al. [33] offers a useful framework. The hypothesis suggests that physical activity reduces the harmful consequences of stress, thereby preventing stress from negatively affecting an individual’s health status. Although Wunsch et al. did not include sleep as an outcome measure, the underlying mechanism they describe implies that physical activity may influence the relationship between stress and sleep problems. Building on this idea, our study provides new insights, suggesting that studies with experimental or longitudinal study designs could further elucidate whether stress affects the association between physical activity and sleep, as well as whether physical activity moderates the effect of stress level on sleep.
It is essential to consider other potential mechanisms that may have contributed to our findings. First, regarding the association between physical activity levels and sleep problems, previous studies have found that physical activity during the day can lower cortisol levels in the evening, which is related to both stress and sleep [14, 34]. Cortisol levels may have had an effect on findings in this study, as high levels of cortisol in the evening are associated with insomnia [35]. Second, physical activity influences the circadian rhythm, which can have a positive effect on sleep quality if the exercise is carried out during the day [16]. Finally, physical activity raises the core body temperature, followed by a decline in body temperature, which helps facilitate sleepiness [36].
This study contributes to the understanding of the relationship between physical activity and stress, and how they interact to influence sleep outcomes. Given that stress negatively impacts both sleep and motivation for physical activity, a cycle of poor sleep and inactivity may further exacerbate stress. Our findings highlight the importance of maintaining physical activity levels even during periods of high stress. Based on our study, a hypothesis for further exploration and testing, is that physical activity may help disrupt this cycle by improving sleep and reducing stress levels, thereby offering a potential intervention point. Moreover, these findings indicate the relevance of considering mental health, particularly stress, alongside physical activity to prevent sleep problems. While previous studies have shown that sleep problems can negatively impact mental health, including depression, anxiety, and stress [3], our results suggest a potential bidirectional relationship, with physical activity playing a role in this interaction.
Strengths and limitations
A strength of this study is the use of data from the nationally representative Health and Morbidity Study, a large representative survey assessing health and morbidity in the Danish adult population [37].
In addition, to enhance the generalizability of our findings and reduce potential selection bias, we applied non-response weighting to ensure that the respondent group more accurately reflects the broader Danish population. Furthermore, our sensitivity analyses, in which we varied outcome definition, revealed no significant differences in the observed associations. This supports the robustness of our findings and highlights the importance of assessing potential biases that may influence conclusions.
Despite these strengths, some limitations should be acknowledged. The cross-sectional design prevents conclusions about causality or the temporal relationship between physical activity and sleep problems. Reverse causation cannot be entirely excluded, nor can the potential influence of other contributing factors. Although key confounders were controlled for, the possibility of residual confounding remains. For instance, chronic illness may have played a role in shaping the observed associations.
Due to the nature of self-reported data, social desirability bias may have influenced the results. Participants may have overestimated their physical activity level, either unintentionally or in order to present themselves in a more positive light. Furthermore, this study does not distinguish between individuals who are slightly or very bothered by sleep problems.
A particular concern is the measurement of stress and its generalizability. Stress was assessed using PSS, which evaluates whether individuals perceived their life as unpredictable, uncontrollable, or overloading during the past month. The group with high stress levels was therefore likely to include both individuals with acute/temporary stress and chronic stress [38]. Further, we used a cut-off point at 18, consistent with previous research [26]. A higher threshold, such as 25, might have excluded individuals facing temporary high-pressure situations rather than those with more severe, prolonged stress.
Finally, it should be noted that data for the present study were collected in 2021, during the COVID-19 pandemic, which may have affected health behaviours in Denmark due to lockdown and restrictions [21]. During this period, more people reported sleep problems and physical activity decreased in several Western countries [39, 40]. No clear validity issues were identified [21], however, the potential impact of COVID-19 on public health should be considered.
Overall, the results of this cross-sectional study suggest that higher levels of leisure-time physical activity are associated with a lower prevalence of sleep problems. This association is significant for respondents with both high and low stress levels.
Future research should explore the underlying causal mechanisms between physical activity and sleep problems and the role of stress in optimizing sleep benefits from physical activity.
Supplementary Material
Contributor Information
Anna P B Bjerkén, Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark.
Hannah Ahrensberg, National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
Susan Andersen, National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
Mette Aadahl, Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Anne I Christensen, National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
Christina B Petersen, Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark; National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
Supplementary data
Supplementary data are available at EURPUB online.
Conflict of interest: None declared.
Funding
None declared.
Data availability
The data underlying this article were provided by National Institute of Public Health, University of Southern Denmark under licence. Data will be shared on request to the corresponding author with permission of National Institute of Public Health, University of Southern Denmark.
Key points.
The study examines cross-sectional associations between self-reported leisure-time physical activity and sleep problems, as well as the potential moderating role of stress.
Odds ratio for having sleep problems was higher when being sedentary in leisure time compared to being lightly physically active.
Odds ratio for having sleep problems was lower when being moderately to vigorously physically active in leisure time compared to being lightly physically active.
Higher levels of leisure-time physical activity appear to be associated with a lower prevalence of sleep problems, even among individuals who experience high levels of stress.
References
- 1. Damgaard AJ, Sørensen JB, Jensen MM et al. The association between sleep, mental health, and health behaviours: a Danish population-based cross-sectional study. Scand J Public Health 2024;11:14034948241262366. [DOI] [PubMed] [Google Scholar]
- 2. Medic G, Wille M, Hemels ME. Short- and long-term health consequences of sleep disruption. Nat Sci Sleep 2017;9:151–61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Scott AJ, Webb TL, James MM-S et al. Improving sleep quality leads to better mental health: a meta-analysis of randomised controlled trials. Sleep Med Rev 2021;60:101556. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Kerkhof GA. Epidemiology of sleep and sleep disorders in The Netherlands. Sleep Med 2017;30:229–39. [DOI] [PubMed] [Google Scholar]
- 5. Knutson KL, Cauter EV, Rathouz PJ et al. Trends in the prevalence of short sleepers in the USA: 1975–2006. Sleep 2010;33:37–45. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Kronholm E, Partonen T, Laatikainen T et al. Trends in self-reported sleep duration and insomnia-related symptoms in Finland from 1972 to 2005: a comparative review and re-analysis of Finnish population samples. J Sleep Res 2008;17:54–62. [DOI] [PubMed] [Google Scholar]
- 7. Chattu VK, Manzar MD, Kumary S et al. The global problem of insufficient sleep and its serious public health implications. Healthcare (Basel) 2018;7:1–16. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Colten H, Altevogt B. Extent and health consequences of chronic sleep loss and sleep disorders. In: Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington (DC): 3: Institute of Medicine (US) Committee on Sleep Medicine and Research, 2006. [PubMed] [Google Scholar]
- 9. Duncan MJ, Murphy L, Oftedal S et al. The associations between physical activity, sedentary behaviour, and sleep with mortality and incident cardiovascular disease, cancer, diabetes and mental health in adults: a systematic review and meta-analysis of prospective cohort studies. J Act Sedentary Sleep Behav 2023;2:19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10. Åkerstedt T, Mittendorfer-Rutz E, Rahman S. Sleep disturbance and work-related mental strain: a national prospective cohort study of the prediction of subsequent long-term sickness absence, disability pension and mortality. Scand J Public Health 2020;48:888–95. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. Khan MA, Al-Jahdali H. The consequences of sleep deprivation on cognitive performance. Neurosciences (Riyadh) 2023;28:91–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Kredlow MA, Capozzoli MC, Hearon BA et al. The effects of physical activity on sleep: a meta-analytic review. J Behav Med 2015;38:427–49. [DOI] [PubMed] [Google Scholar]
- 13. Amiri S, Hasani J, Satkin M. Effect of exercise training on improving sleep disturbances: a systematic review and meta-analysis of randomized control trials. Sleep Med 2021;84:205–18. [DOI] [PubMed] [Google Scholar]
- 14. Hackney A, Viru A. Twenty-four-hour cortisol response to multiple daily exercise sessions of moderate and high intensity. Clin Physiol 1999;19:178–82. [DOI] [PubMed] [Google Scholar]
- 15. Haupt S, Eckstein ML, Wolf A et al. Eat, train, sleep-retreat? hormonal interactions of intermittent fasting, exercise and circadian rhythm. Biomolecules 2021;11:1–19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Shen B, Ma C, Wu G et al. Effects of exercise on circadian rhythms in humans. Front Pharmacol 2023;14:1282357. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17. Carpi M, Cianfarani C, Vestri A. Sleep quality and its associations with physical and mental health-related quality of life among university students: a cross-sectional study. Int J Environ Res Public Health 2022;19:1–13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. Kalmbach DA, Anderson JR, Drake CL. The impact of stress on sleep: pathogenic sleep reactivity as a vulnerability to insomnia and circadian disorders. J Sleep Res 2018;27:e12710. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Stults-Kolehmainen MA, Sinha R. The effects of stress on physical activity and exercise. Sports Med 2014;44:81–121. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20. Jensen H, Ekholm O, Davidsen M et al. The Danish health and morbidity surveys: study design and participant characteristics. BMC Med Res Methodol 2019;19:91–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21. Jensen H, Møller S, Davidsen M et al. Materiale og metode Sundheds- og sygelighedsundersøgelsen 2021. Statens Institut for Folkesundhed, SDU, 2022.
- 22. Grimby G, Börjesson M, Jonsdottir IH et al. The “Saltin–Grimby physical activity level scale” and its application to health research. Scand J Med Sci Sports 2015;25(Suppl 4):119–25. [DOI] [PubMed] [Google Scholar]
- 23. Eskildsen A, Dalgaard VL, Nielsen KJ et al. Cross-cultural adaptation and validation of the Danish consensus version of the 10-item perceived stress scale. Scand J Work Environ Health 2015;41:486–90. [DOI] [PubMed] [Google Scholar]
- 24. CORC. Perceived Stress Scale (PSS-10): Child Outcomes Research Consortium. n.d. https://www.corc.uk.net/outcome-experience-measures/perceived-stress-scale-pss-10 (19 May 2025, date last accessed).
- 25. Buhelt LP, Pisinger C, Andreasen AH. Smoking and stress in the general population in Denmark. Tob Prev Cessat 2021;7:27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26. Schmidt SAJ, Sørensen HT, Langan SM et al. Perceived pshychological stress and risk of herpes zoster: a nationwide population-based cohort study. Br J Dermatol 2021;185:130–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27. Sundhedsstyrelsen. Anbefalinger om alkohol. Sundhedsstyrelsen, n.d. https://www.sst.dk/da/Borger/En-sund-hverdag/Alkohol/Anbefalinger-om-alkohol (19 May 2025, date last accessed).
- 28. WHO. A Healthy Lifestyle—WHO Recommendations. World Health Organization, 2010. https://www.who.int/europe/news-room/fact-sheets/item/a-healthy-lifestyle—who-recommendations (30 January 2025, date last accessed).
- 29. Jennum P, Bonke J, Clark A et al. Søvn og sundhed. København: Vidensråd for forebyggelse, 2015. [Google Scholar]
- 30. Sejbuk M, Mirończuk-Chodakowska I, Witkowska AM. Sleep quality: a narrative review on nutrition, stimulants, and physical activity as important factors. Nutrients 2022;14:1912. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31. Ashdown-Franks G, Koyanagi A, Vancampfort D et al. Sedentary behavior and perceived stress among adults aged >/=50 years in six low- and middle- income countries. Maturitas 2018;116:100–7. [DOI] [PubMed] [Google Scholar]
- 32. An K, Jang J, Kim J. Sedentary behavior and sleep duration are associated with both stress symptoms and suicidal thoughts in Korean adults. Tohoku J Exp Med 2015;237:279–86. [DOI] [PubMed] [Google Scholar]
- 33. Wunsch K, Kasten N, Fuchs R. The effect of physical activity on sleep quality, well- being, and affect in academic stress periods. Nat Sci Sleep 2017;9:117–26. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34. Nys LD, Anderson K, Ofosu EF et al. The effects of physical activity on cortisol and sleep: a systematic review and meta-analysis. Psychoneuroendocrinology 2022;143:1–12. [DOI] [PubMed] [Google Scholar]
- 35. Dressle RJ, Feige B, Spiegelhalder K et al. HPA axis activity in patients with chronic insomnia: a systematic review and meta-analysis of case–control studies. Sleep Med Rev 2022;62:101588. [DOI] [PubMed] [Google Scholar]
- 36. JHK Medicine. Exercising for Better Sleep. Johns Hopkins Medicine; n.d. https://www.hopkinsmedicine.org/health/wellness-and-prevention/exercising-for-better-sleep (26 November 2025, date last accessed).
- 37. Christensen AI. The National Representative Health and Morbidity Studies (SUSY). Syddansk Universitet: Statens institut for Folkesundhed, n.d. https://www.sdu.dk/en/sif/forskning/projekter/sundheds_og_sygelighedsundersoegelserne (12 December 2024, date last accessed). [Google Scholar]
- 38. Harris KM, Gaffey AE, Schwartz JE et al. The perceived stress scale as a measure of stress: decomposing score variance in longitudinal behavioral medicine studies. Ann Behav Med 2023;57:846–54. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39. Alimoradi Z, Gozal D, Tsang H et al. Genderspecific estimates of sleep problems during the COVID-19 pandemic: systematic review and meta-analysis. J Sleep Res 2022;31:e13432. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40. Petersen C, Kruger C, Guldager J et al. Are changes in physical activity during COVID-19 associated with mental health among Danish university students? Front Public Health 2023;11:1126240. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
The data underlying this article were provided by National Institute of Public Health, University of Southern Denmark under licence. Data will be shared on request to the corresponding author with permission of National Institute of Public Health, University of Southern Denmark.
Key points.
The study examines cross-sectional associations between self-reported leisure-time physical activity and sleep problems, as well as the potential moderating role of stress.
Odds ratio for having sleep problems was higher when being sedentary in leisure time compared to being lightly physically active.
Odds ratio for having sleep problems was lower when being moderately to vigorously physically active in leisure time compared to being lightly physically active.
Higher levels of leisure-time physical activity appear to be associated with a lower prevalence of sleep problems, even among individuals who experience high levels of stress.