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Associations of exercise characteristics and exercise partners with self-reported atopic dermatitis among Japanese university students

Year: 2026

Type: article

Abstract: Background Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease; however, its association with physical activity remains inconclusive. The role of the social context of exercise, including exercise partners, is also unclear. This study examined associations between exercise characteristics and self-reported AD among Japanese young adults. Methods This cross-sectional study included 12,494 university students in Japan. Exercise frequency, perceived intensity, and exercise partner were assessed using a self-administered questionnaire. Self-reported AD was ascertained by asking participants whether they had previously been diagnosed with AD. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression. Each exercise characteristic was first examined individually, adjusting for age, sex, body mass index, drinking, smoking, systolic blood pressure, and self-reported sleep duration. Exercise frequency, intensity, and partner were then entered simultaneously into a mutually adjusted model to assess whether these associations were independent of one another. Results The prevalence of self-reported AD was 6.5%. In the individually adjusted models, high exercise frequency (≥ 4 times/week), intense exercise, and group exercise were associated with lower odds of AD compared with no exercise, exercising alone, or light exercise, respectively (adjusted ORs: 0.72 [95% CI: 0.56–0.92], 0.75 [0.61–0.91], and 0.71 [0.56–0.88]); exercising alone or with friends was not significantly associated with AD. When exercise frequency, intensity, and partner were mutually adjusted for one another, the overall associations of exercise frequency and intensity with AD were no longer statistically significant. For exercise partner, group exercise remained associated with lower odds of AD than exercising alone (OR: 0.77 [95% CI: 0.59–0.98]), although the overall association across categories of exercise partner did not reach statistical significance. Conclusions Higher exercise frequency, greater exercise intensity, and group exercise were each inversely associated with self-reported AD when examined individually. However, after mutual adjustment for other exercise characteristics, these associations were generally attenuated, and only a modest inverse association for group exercise remained. These findings should therefore be interpreted with caution, and causal inference is further limited by the cross-sectional design.

Source: Journal of PHYSIOLOGICAL ANTHROPOLOGY

DOI: 10.1186/s40101-026-00449-3