Regular exercise frequency linked to lower risk of depression and anxiety among students

A Norwegian study reveals that consistent, repeatable physical activity may reduce the likelihood of depression and anxiety in students over time, emphasising the importance of routine over intensity or duration.

Students who keep up a regular exercise habit appear less likely to meet the clinical threshold for depression or anxiety a year later than those who rarely work out, according to a new Norwegian study that tracked mental health over time rather than taking a single snapshot. The clearest pattern was not how hard students trained, but how often they did it: frequent, repeatable activity was more consistently linked to better outcomes than punishing sessions or very long workouts. (journals.plos.org)

The research, published in PLOS One on 19 August, drew on Norway’s Students’ Health and Wellbeing Study, a national survey sent every four years to full-time higher-education students. In the 2022 round, 59,544 of 169,572 invited students replied; 53,362 of those were aged 18 to 35 and had complete exercise data. Roughly a year later, from 24 January to 6 February 2023, 10,460 students completed a self-administered version of the Composite International Diagnostic Interview, a World Health Organization tool designed to identify disorders including major depressive episode and generalized anxiety disorder using DSM-5 criteria. (journals.plos.org)

After accounting for demographic differences and baseline psychological distress, the gap between active and inactive students remained. Compared with students who exercised almost every day, women who never or seldom exercised had a 15% higher adjusted risk of a common mental disorder at follow-up, while men had a 33% higher adjusted risk. Students who fell short of the WHO benchmark of at least 150 minutes of moderate-to-vigorous activity a week also carried a higher adjusted risk: 10% higher among women and 17% higher among men, according to reporting that unpacked the paper’s adjusted estimates. Total weekly activity showed a stepped pattern too, with risk dropping as exercise rose to about 10 hours a week; among women the lowest estimated risk was around five to six hours, while among men it continued to decline across the measured range. (journals.plos.org)

The sex split was more complicated once the researchers broke exercise into its parts. For women, lower intensity was linked to a higher later risk of depression or anxiety, while for men the more notable warning sign was shorter sessions. Even so, the authors said frequency was the most reliable signal overall, with intensity and duration showing weaker, less uniform patterns. In the main models, the team adjusted not only for age and sex but for factors including parental education, migration background, relationship status, whether students had children, whether they lived alone, and baseline distress measured on the Hopkins Symptom Checklist. (journals.plos.org)

Michael Grasdalsmoen of Western Norway University of Applied Sciences, who led the analysis with colleagues at the University of Bergen and the Norwegian Institute of Public Health, offered a deliberately modest takeaway. “I would say: use those 20 minutes. Go for a brisk walk, run, cycle, ski if you have the opportunity, or do another activity you enjoy and can easily repeat,” he told Earth.com. In a PLOS-backed summary carried by Medical Xpress, the authors said: “Our findings show that students who engage in regular physical exercise are at lower risk of developing common mental disorders over time. These findings highlight the importance of making physical activity an accessible and natural part of student life.” They added that student mental health “should be recognized as an important part of a healthy learning environment.” (earth.com)

Why this matters is not hard to see. Common mental disorders are among the leading causes of disability in young adults, and the move into higher education often coincides with disrupted sleep, academic competition, loneliness, financial pressure and the loss of established routines. Reporting around the study pointed to several plausible ways exercise could help: repeated activity may improve sleep, regulate stress, reduce low-grade inflammation, support brain signalling, build a sense of mastery and create social contact. WHO guidance for adults recommends 150 to 300 minutes of moderate aerobic activity a week, or 75 to 150 minutes of vigorous activity, plus muscle-strengthening work on at least two days; just as importantly, the guidance stresses that some activity is better than none. (journals.plos.org)

The authors were careful not to oversell the findings. This was an observational study, so it cannot prove that exercise itself prevented illness. Diagnostic disorder was not measured at baseline, meaning the follow-up combined new, persistent and recurring cases rather than strictly new ones. Exercise levels were self-reported, which leaves room for recall error and overstatement. And while the team used weighting to reduce bias, only 17.6% of the original baseline sample completed the later diagnostic assessment, raising the possibility that students with the most severe mental-health problems were under-represented. The paper also says unmeasured factors such as therapy, psychotropic medication and substance use could have influenced both exercise habits and later mental health. (journals.plos.org)

Even with those cautions, the study adds a more clinically grounded layer to a large body of work linking movement and mood, because it followed students forward and used a diagnostic instrument rather than a symptom checklist alone. It was funded by the Norwegian Ministry of Education and Research and the Norwegian Ministry of Health and Care Services, with the funders having no role in the study, according to the PLOS release. The practical message is also narrower than many fitness slogans: for students under pressure, a routine they can actually sustain may matter more than any heroic training plan. (medicalxpress.com)