{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:37:59Z","timestamp":1785411479032,"version":"3.56.0"},"reference-count":39,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T00:00:00Z","timestamp":1784764800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100019485","name":"Univers Foundation","doi-asserted-by":"crossref","award":["2024"],"award-info":[{"award-number":["2024"]}],"id":[{"id":"10.13039\/100019485","id-type":"DOI","asserted-by":"crossref"}]},{"award":["2024"],"award-info":[{"award-number":["2024"]}],"id":[{"id":"https:\/\/ror.org\/041mjh419","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Children"],"abstract":"<jats:p>Background\/Objectives: This study evaluated the impact of short-duration physical exercise sessions and daily exercise recordings on the physical health and psychological health of junior high school students in Japan. Methods: A 3-month longitudinal school-based intervention initially enrolled 235 students, and the final analysis included 127 students who completed the program. The study was conducted using a single-arm pre\u2013post design without a control group. The intervention included biweekly group exercise sessions and daily activity recordings. Students were separated into two groups based on their screen time (\u22654 h per day or &lt;4 h per day). Results: After the intervention, a significant decrease in screen time was observed in the group with baseline screen time of 4 h or more, whereas the group with baseline screen time of less than 4 h showed an increase in daily screen time. The results indicated a significant increase in body mass index and trunk muscle mass in both groups. For psychological measures, including the General Self-Efficacy Scale and Communicative and Critical Health Literacy scale, no significant changes over time or group \u00d7 time interactions were observed, although post-intervention scores were significantly higher in the lower screen time group compared to the higher screen time group. However, significant changes in skeletal muscle index, eHealth literacy, and sleep duration were not observed. Conclusions: Due to the lack of a control group, these findings remain preliminary, and observed changes cannot be definitively attributed solely to the intervention. However, the program showed potential in reducing excessive screen time and increasing trunk muscle mass. Future randomized controlled trials are required to confirm the true efficacy of the intervention.<\/jats:p>","DOI":"10.3390\/children13080980","type":"journal-article","created":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T01:18:51Z","timestamp":1784855931000},"page":"980","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Preliminary Impacts of a 3-Month School-Based Exercise and Data Recording Intervention on Lifestyle Habits, Psychological Health, and Physical Health in Japanese Adolescents"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6730-4848","authenticated-orcid":false,"given":"Yasuaki","family":"Kusumoto","sequence":"first","affiliation":[{"name":"Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eri","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-2633-3996","authenticated-orcid":false,"given":"Yasuhiro","family":"Endo","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8487-712X","authenticated-orcid":false,"given":"Kanako","family":"Okazaki","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akihiko","family":"Asao","sequence":"additional","affiliation":[{"name":"Department of Occupational Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshinobu","family":"Tanaka","sequence":"additional","affiliation":[{"name":"Department of Occupational Therapy, School of Health Sciences, Fukushima Medical University, Fukushima City 960-8516, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/S2352-4642(19)30323-2","article-title":"Global trends in insufficient physical activity among adolescents: A pooled analysis of 298 population-based surveys with 1.6 million participants","volume":"4","author":"Guthold","year":"2020","journal-title":"Lancet Child Adolesc. Health"},{"key":"ref_2","unstructured":"Japan Sports Agency (2026, June 19). FY2021 National Survey Results on Physical Fitness, Athletic Ability, Exercise Habits, etc. Available online: https:\/\/www.mext.go.jp\/sports\/content\/20211222-spt_sseisaku02-000019583_111.pdf."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.clnesp.2022.06.001","article-title":"Sedentary behavior, physical inactivity, abdominal obesity and obesity in adults and older adults: A systematic review and meta-analysis","volume":"50","author":"Silveira","year":"2022","journal-title":"Clin. Nutr. ESPEN"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Sember, V., Jurak, G., Kova\u010d, M., Morrison, S.A., and Starc, G. (2020). Children\u2019s physical activity, academic performance, and cognitive functioning: A systematic review and meta-analysis. Front. Public Health, 8.","DOI":"10.3389\/fpubh.2020.00307"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"100322","DOI":"10.1016\/j.mhpa.2020.100322","article-title":"Physical activity, mental health and academic achievement: A cross-sectional study of Norwegian adolescents","volume":"18","author":"Anderssen","year":"2020","journal-title":"Ment. Health Phys. Act."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1186\/s12966-017-0541-8","article-title":"Prevalence, trajectories, and determinants of television viewing time in an ethnically diverse sample of young children from the UK","volume":"14","author":"Barber","year":"2017","journal-title":"Int. J. Behav. Nutr. Phys. Act."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"909","DOI":"10.1007\/s00431-016-2720-z","article-title":"Screen time is associated with depressive symptomatology among obese adolescents: A HEARTY study","volume":"175","author":"Goldfield","year":"2016","journal-title":"Eur. J. Pediatr."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Haghjoo, P., Siri, G., Soleimani, E., Farhangi, M.A., and Alesaeidi, S. (2022). Screen time increases overweight and obesity risk among adolescents: A systematic review and dose-response meta-analysis. BMC Prim. Care, 23.","DOI":"10.1186\/s12875-022-01761-4"},{"key":"ref_9","unstructured":"Children and Families Agency (2026, June 19). FY2023 Survey on Internet Usage Environment of Young People. Available online: https:\/\/www.cfa.go.jp\/assets\/contents\/node\/basic_page\/field_ref_resources\/9a55b57d-cd9d-4cf6-8ed4-3da8efa12d63\/fc117374\/20240226_policies_youth-kankyou_internet_research_results-etc_09.pdf."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"621","DOI":"10.1007\/s00431-017-2886-z","article-title":"Association of lifestyle behaviours with self-esteem through health-related quality of life in Spanish adolescents","volume":"176","author":"Knox","year":"2017","journal-title":"Eur. J. Pediatr."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Villodres, G.C., Salvador-P\u00e9rez, F., Chac\u00f3n-Cuberos, R., and Muros, J.J. (2023). Lifestyle behaviours, self-esteem and academic performance in primary education students\u2014A structural equation model according to sex and school type. Children, 10.","DOI":"10.3390\/children10111769"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Wu, J., Yang, Y., Yu, H., Li, L., Chen, Y., and Sun, Y. (2023). Comparative effectiveness of school-based exercise interventions on physical fitness in children and adolescents: A systematic review and network meta-analysis. Front. Public Health, 11.","DOI":"10.3389\/fpubh.2023.1194779"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Weston, K.L., Azevedo, L.B., Bock, S., Weston, M., George, K.P., and Batterham, A.M. (2016). Effect of Novel, School-Based High-Intensity Interval Training (HIT) on Cardiometabolic Health in Adolescents: Project FFAB (Fun Fast Activity Blasts)\u2014An Exploratory Controlled Before-And-After Trial. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0159116"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Cline, A., Knox, G., De Martin Silva, L., and Draper, S. (2021). A process evaluation of a UK classroom-based physical activity intervention\u2014\u2018Busy Brain Breaks\u2019. Children, 8.","DOI":"10.3390\/children8020063"},{"key":"ref_15","unstructured":"Baker, J.S., Buchan, D.S., Malina, R.M., and Thomas, N.E. (2022). Benefits of high intensity anaerobic exercise for adolescents and school children. Br. J. Sports Med., Available online: https:\/\/bjsm.bmj.com\/content\/benefits-high-intensity-anaerobic-exercise-adolescents-and-school-children."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1123\/jtpe.2017-0072","article-title":"Adolescent physical activity and motivational profiles while keeping a physical activity record","volume":"37","author":"Fullmer","year":"2018","journal-title":"J. Teach. Phys. Educ."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Moore, R., Edmondson, L., Gregory, M., Griffiths, K., and Freeman, E. (2023). Barriers and facilitators to physical activity and further digital exercise intervention among inactive British adolescents in secondary schools: A qualitative study with physical education teachers. Front. Public Health, 11.","DOI":"10.3389\/fpubh.2023.1193669"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1039","DOI":"10.1001\/jamapediatrics.2023.3057","article-title":"Screen time at Age 1 year and communication and problem-solving developmental delay at 2 and 4 years","volume":"177","author":"Takahashi","year":"2023","journal-title":"JAMA Pediatr."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1507\/endocrj.EJ23-0343","article-title":"Association between screen time, including that for smartphones, and overweight\/obesity among children in Japan: NICE EVIDENCE Study 4","volume":"71","author":"Ikeda","year":"2024","journal-title":"Endocr. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2273","DOI":"10.1007\/s00431-022-04420-z","article-title":"Adolescent screen time: Associations with school stress and school satisfaction across 38 countries","volume":"181","author":"Khan","year":"2022","journal-title":"Eur. J. Pediatr."},{"key":"ref_21","unstructured":"Liguori, G., and American College of Sports Medicine (2022). ACSM\u2019s Guidelines for Exercise Testing & Prescription, Wolters Kluwer. [11th ed.]."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1037\/0033-295X.84.2.191","article-title":"Self-efficacy: Toward a unifying theory of behavioral change","volume":"84","author":"Bandura","year":"1977","journal-title":"Psychol. Rev."},{"key":"ref_23","unstructured":"Weinman, J., Wright, S., and Johnston, M. (1995). Generalized self-efficacy scale. Measures in Health Psychology: A User\u2019s Portfolio. Causal and Control Beliefs, NFER-Nelson."},{"key":"ref_24","first-page":"73","article-title":"An attempt to develop a general self-efficacy scale","volume":"12","author":"Sakano","year":"1986","journal-title":"Jpn. J. Behav. Ther."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1093\/heapro\/15.3.259","article-title":"Health literacy as a public health goal: A challenge for contemporary health education and communication strategies into the 21st century","volume":"15","author":"Nutbeam","year":"2000","journal-title":"Health Promot. Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"874","DOI":"10.2337\/dc07-1932","article-title":"Measuring functional, communicative, and critical health literacy among diabetic patients","volume":"31","author":"Ishikawa","year":"2008","journal-title":"Diabetes Care"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e27","DOI":"10.2196\/jmir.8.4.e27","article-title":"eHEALS: The eHealth literacy scale","volume":"8","author":"Norman","year":"2006","journal-title":"J. Med. Internet Res."},{"key":"ref_28","first-page":"361","article-title":"Developing (Japanese version) of the eHealth Literacy Scale (eHEALS)","volume":"58","author":"Mitsutake","year":"2011","journal-title":"Nihon Koshu Eisei Zasshi"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/s41256-023-00297-z","article-title":"Screen time among school-aged children of aged 6\u201314: A systematic review","volume":"8","author":"Qi","year":"2023","journal-title":"Glob. Health Res. Policy"},{"key":"ref_30","first-page":"CS354544","article-title":"Daily screen time among teenagers: United States, July 2021\u2013December 2023","volume":"513","author":"Zablotsky","year":"2024","journal-title":"NCHS Data Brief"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.sleh.2023.02.005","article-title":"Bedtime screen use behaviors and sleep outcomes: Findings from the Adolescent Brain Cognitive Development (ABCD) Study","volume":"9","author":"Nagata","year":"2023","journal-title":"Sleep Health"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Hartley, S., Royant-Parola, S., Zayoud, A., Gremy, I., and Matulonga, B. (2022). Do both timing and duration of screen use affect sleep patterns in adolescents?. PLoS ONE, 17.","DOI":"10.1371\/journal.pone.0276226"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"110","DOI":"10.24953\/turkjped.2021.1264","article-title":"Promoting adolescent health: Health literacy, self-efficacy and internet use","volume":"64","author":"Ceylan","year":"2022","journal-title":"Turk. J. Pediatr."},{"key":"ref_34","first-page":"e262","article-title":"The relationship between health literacy, self-efficacy, and self-care behaviors in older adults with hypertension in the north of Iran","volume":"6","author":"Darvishpour","year":"2022","journal-title":"Health Lit. Res. Pract."},{"key":"ref_35","unstructured":"Ministry of Education, Culture, Sports, Science and Technology (2026, June 19). A Guide to Health Education in Elementary Schools to Foster the Ability to Live, Available online: https:\/\/www.mext.go.jp\/a_menu\/kenko\/hoken\/__icsFiles\/afieldfile\/2019\/07\/12\/1334052_2.pdf."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Taba, M., Allen, T.B., Caldwell, P.H.Y., Skinner, S.R., Kang, M., McCaffery, K., and Scott, K.M. (2022). Adolescents\u2019 self-efficacy and digital health literacy: A cross-sectional mixed methods study. BMC Public Health, 22.","DOI":"10.1186\/s12889-022-13599-7"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Detter, F., Nilsson, J.\u00c5., Karlsson, C., Dencker, M., Rosengren, B.E., and Karlsson, M.K. (2014). A 3-year school-based exercise intervention improves muscle strength\u2014A prospective controlled population-based study in 223 children. BMC Musculoskelet. Disord., 15.","DOI":"10.1186\/1471-2474-15-353"},{"key":"ref_38","first-page":"307063","article-title":"A school-based exercise intervention program increases muscle strength in prepubertal boys","volume":"2010","author":"Daly","year":"2010","journal-title":"Int. J. Pediatr."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Ko\u017alenia, D., Popowczak, M., Szafraniec, R., Alvarez, C., and Domaradzki, J. (2024). Changes in muscle mass and strength in adolescents following high-intensity functional training with bodyweight resistance exercises in physical education lessons. J. Clin. Med., 13.","DOI":"10.3390\/jcm13123400"}],"container-title":["Children"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/8\/980\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T04:20:15Z","timestamp":1784953215000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/8\/980"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,23]]},"references-count":39,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["children13080980"],"URL":"https:\/\/doi.org\/10.3390\/children13080980","relation":{},"ISSN":["2227-9067"],"issn-type":[{"value":"2227-9067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,23]]}}}