{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T16:29:23Z","timestamp":1787502563705,"version":"build-2736575974"},"reference-count":35,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2022,11,18]],"date-time":"2022-11-18T00:00:00Z","timestamp":1668729600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Reportedly, daytime napping affects the physical fitness of athletes. However, results of these studies are conflicting, and may not be generalizable to all populations. Early adulthood is an important period linking adolescents and adults, during which building good physical fitness is crucial for their remaining lives. Thus, we investigated whether daytime napping duration is associated with physical fitness among Chinese university students. This study was based on an annual physical health examination for all university students and included 11,199 participants (6690 males; 4509 females). The daytime napping duration was assessed using a self-report questionnaire. Physical fitness was measured with a 50 m sprint; 1000 m (for males) and 800 m (for females) runs; standing long jump, sit-and-reach, pull-up (for males), and sit-up (for females) tests; and vital capacity. The adjusted association was evaluated using analysis of covariance. Of the participants, 86% napped regularly. After covariate adjustment was performed, significant V-shaped associations were observed between the daytime napping duration and the 50 m sprint and 800 m run results in males and females. Inverted V-shaped associations were observed between the daytime napping duration and the sit-and-reach, standing long jump, and pull-up test performances and vital capacity in males and between the daytime napping duration and the standing long jump test performance in females. Daytime napping for &lt;30 min may have beneficial effects on physical fitness among university students.<\/jats:p>","DOI":"10.3390\/ijerph192215250","type":"journal-article","created":{"date-parts":[[2022,11,18]],"date-time":"2022-11-18T06:02:29Z","timestamp":1668751349000},"page":"15250","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Duration of Daytime Napping Is Related to Physical Fitness among Chinese University Students"],"prefix":"10.3390","volume":"19","author":[{"given":"Lingfeng","family":"Kong","sequence":"first","affiliation":[{"name":"Department of Physical Education, Hohai University, 1 Xikang Road, Nanjing 210098, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yufei","family":"Cui","sequence":"additional","affiliation":[{"name":"Department of Physical Education, Huaiyin Institute of Technology, Huaian 223003, China"},{"name":"Department of Medicine and Science in Sports and Exercise, Graduate School of Medicine, Tohoku University, Sendai 9808575, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiang","family":"Gong","sequence":"additional","affiliation":[{"name":"Department of Physical Education, Huaiyin Institute of Technology, Huaian 223003, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,18]]},"reference":[{"key":"ref_1","unstructured":"China Institute of Sport Science (2022, November 11). The Fifth Bulletin on National Physical Fitness Monitoring. Available online: https:\/\/www.ciss.cn\/zhxw\/info\/2021\/32028.html."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1046\/j.1532-5415.2002.50217.x","article-title":"Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79: The health, aging and body composition study","volume":"50","author":"Visser","year":"2002","journal-title":"J. Am. Geriatr. Soc."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1177\/1941738120931755","article-title":"Physical Fitness and Bone Health in Young Athletes and Nonathletes","volume":"12","author":"Magalhaes","year":"2020","journal-title":"Sports Health Multidiscip. Approach"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1111\/j.1447-0594.2008.00492.x","article-title":"Six-year prospective study of physical fitness and incidence of disability among community-dwelling Japanese elderly women","volume":"9","author":"Tainaka","year":"2009","journal-title":"Geriatr. Gerontol. Int."},{"key":"ref_5","first-page":"1410","article-title":"Physical fitness, but not physical activity, is associated with mental health in apparently healthy young adults","volume":"62","author":"Blumenburg","year":"2021","journal-title":"J. Sports Med. Phys. Fit."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9791281","DOI":"10.1155\/2019\/9791281","article-title":"Physical Activity, Sedentary Behavior, and Quality of Life among University Students","volume":"2019","author":"Nowak","year":"2019","journal-title":"Biomed. Res. Int."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/sj.ijo.0803774","article-title":"Physical fitness in childhood and adolescence: A powerful marker of health","volume":"32","author":"Ortega","year":"2008","journal-title":"Int. J. Obes."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1016\/0895-4356(95)00533-1","article-title":"Physical-strength tests and mortality among visitors to health-promotion centers in Japan","volume":"48","author":"Fujita","year":"1995","journal-title":"J. Clin. Epidemiol."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Kljajevic, V., Stankovic, M., Dordevic, D., Trkulja-Petkovic, D., Jovanovic, R., Plazibat, K., Orsolic, M., Curic, M., and Sporis, G. (2021). Physical Activity and Physical Fitness among University Students-A Systematic Review. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19010158"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Bogataj, S., Trajkovic, N., Cadenas-Sanchez, C., and Sember, V. (2021). Effects of School-Based Exercise and Nutrition Intervention on Body Composition and Physical Fitness in Overweight Adolescent Girls. Nutrients, 13.","DOI":"10.3390\/nu13010238"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"156","DOI":"10.5993\/AJHB.42.1.15","article-title":"Frequency of Breakfast and Physical Fitness among Chinese College Students","volume":"42","author":"Cui","year":"2018","journal-title":"Am. J. Health Behav."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Gu, M., Liu, C.C., Hsu, C.C., Lu, C.J., Lee, T.S., Chen, M., and Ho, C.C. (2021). Associations of sleep duration with physical fitness performance and self-perception of health: A cross-sectional study of Taiwanese adults aged 23\u201345. BMC Public Health, 21.","DOI":"10.1186\/s12889-021-10636-9"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2553","DOI":"10.1080\/02640414.2020.1793651","article-title":"Effects of a 30 min nap opportunity on cognitive and short-duration high-intensity performances and mood states after a partial sleep deprivation night","volume":"38","author":"Souissi","year":"2020","journal-title":"J. Sports Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"112673","DOI":"10.1016\/j.physbeh.2019.112673","article-title":"Effect of different nap opportunity durations on short-term maximal performance, attention, feelings, muscle soreness, fatigue, stress and sleep","volume":"211","author":"Hsouna","year":"2019","journal-title":"Physiol. Behav."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1993","DOI":"10.1097\/HJH.0000000000000291","article-title":"The effects of midday nap duration on the risk of hypertension in a middle-aged and older Chinese population: A preliminary evidence from the Tongji-Dongfeng Cohort Study, China","volume":"32","author":"Cao","year":"2014","journal-title":"J. Hypertens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"38075","DOI":"10.1038\/srep38075","article-title":"J-curve relation between daytime nap duration and type 2 diabetes or metabolic syndrome: A dose-response meta-analysis","volume":"6","author":"Yamada","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"741","DOI":"10.3724\/zdxbyxb-2021-0296","article-title":"Association between napping status and depressive symptoms in urban residents during the COVID-19 epidemic","volume":"50","author":"Lin","year":"2021","journal-title":"J. Zhejiang Univ. Med. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"544","DOI":"10.12965\/jer.130082","article-title":"The relationship between mental health and health-related physical fitness of university students","volume":"9","author":"Jeoung","year":"2013","journal-title":"J. Exerc. Rehabil."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1097\/MRR.0000000000000238","article-title":"Fatigue and physical fitness of mildly disabled persons with multiple sclerosis: A cross-sectional study","volume":"40","author":"Valet","year":"2017","journal-title":"Int. J. Rehabil. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1557","DOI":"10.1080\/02640410701244983","article-title":"The role of a short post-lunch nap in improving cognitive, motor, and sprint performance in participants with partial sleep deprivation","volume":"25","author":"Waterhouse","year":"2007","journal-title":"J. Sports Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1080\/02640414.2016.1161208","article-title":"Acute effects of psychological relaxation techniques between two physical tasks","volume":"35","author":"Pelka","year":"2017","journal-title":"J. Sports Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1123\/ijspp.2019-0308","article-title":"Improved Physical Performance and Decreased Muscular and Oxidative Damage With Postlunch Napping After Partial Sleep Deprivation in Athletes","volume":"15","author":"Romdhani","year":"2020","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Boukhris, O., Trabelsi, K., Hill, D.W., Hsouna, H., Abdessalem, R., Ammar, A., Hammouda, O., Clark, C.C.T., Zmijewski, P., and Duking, P. (2022). Physiological response and physical performance after 40 min and 90 min daytime nap opportunities. Res. Sports Med., 1\u20134.","DOI":"10.1080\/15438627.2022.2079979"},{"key":"ref_24","unstructured":"Ministry of Education of the People\u2019s Republic of China (2022, November 11). Notification of <National Student Physical Health Standard> Revised in 2014, Available online: http:\/\/www.moe.gov.cn\/s78\/A17\/twys_left\/moe_938\/moe_792\/s3273\/201407\/t20140708_171692.html."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1396","DOI":"10.1249\/01.MSS.0000078923.96621.1D","article-title":"International physical activity questionnaire: 12-country reliability and validity","volume":"35","author":"Bassett","year":"2003","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1176\/ajp.126.1.116","article-title":"A cross-cultural survey of symptoms in depression","volume":"126","author":"Zung","year":"1969","journal-title":"Am. J. Psychiatry"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"150","DOI":"10.3200\/JACH.57.2.150-158","article-title":"Sleep and behavioral correlates of napping among young adults: A survey of first-year university students in Madrid, Spain","volume":"57","author":"Vgontzas","year":"2008","journal-title":"J. Am. Coll. Health"},{"key":"ref_28","first-page":"248","article-title":"Prevalence of sleep disturbances in college students","volume":"25","author":"Groff","year":"1996","journal-title":"Sleep Res."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Lovato, N., Lack, L., and Wright, H. (2014). The napping behaviour of Australian university students. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0113666"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1046\/j.1365-2869.1998.00087.x","article-title":"The siesta culture concept is not supported by the sleep habits of urban Mexican students","volume":"7","author":"Castano","year":"1998","journal-title":"J. Sleep Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1249\/MSS.0000000000001786","article-title":"Effects of Napping on Alertness, Cognitive, and Physical Outcomes of Karate Athletes","volume":"51","author":"Daaloul","year":"2019","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1464","DOI":"10.1080\/07420528.2018.1490316","article-title":"A brief pre-exercise nap may alleviate physical performance impairments induced by short-term sustained operations with partial sleep deprivation\u2014A field-based study","volume":"35","author":"Keramidas","year":"2018","journal-title":"Chronobiol. Int."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2115","DOI":"10.1007\/s40279-021-01482-1","article-title":"Benefits of Daytime Napping Opportunity on Physical and Cognitive Performances in Physically Active Participants: A Systematic Review","volume":"51","author":"Souabni","year":"2021","journal-title":"Sports Med."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"E416","DOI":"10.1210\/jc.2014-2566","article-title":"Napping reverses the salivary interleukin-6 and urinary norepinephrine changes induced by sleep restriction","volume":"100","author":"Faraut","year":"2015","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1152\/japplphysiol.00133.2007","article-title":"Oxidative protein damage is associated with poor grip strength among older women living in the community","volume":"103","author":"Howard","year":"2007","journal-title":"J. Appl. Physiol."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/22\/15250\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:21:04Z","timestamp":1760145664000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/19\/22\/15250"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,18]]},"references-count":35,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2022,11]]}},"alternative-id":["ijerph192215250"],"URL":"https:\/\/doi.org\/10.3390\/ijerph192215250","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,18]]}}}