JMIR Publications

ABSTRACT

Background:

Existing literature on the association of frequency of muscle-strengthening exercise (MSE) with depression among adolescents is limited and contradictory.

Objective:

The current study aimed to elucidate the association of frequency of MSE with depression among middle and high school students.

Methods:

A total of 27 070 students in grades 7-12 from 376 middle and high schools were surveyed through an anonymous self-administered questionnaire between April and June 2022. Information on MSE participating was self-reported and depression symptoms was assessed using the Patient Health Questionnaire-9 (PHQ-9). Poisson regression was utilized to examine the association between frequency of MSE and depression symptoms.

Results:

The current analyses were performed among 27 006 eligible students. 51.6% were boys and the mean (SD) age was 15.6 (1.7) years. The overall prevalence of meeting MSE recommendations (i.e., engaging in MSE ≥3 days/week) was 34.6% (95%CI: 32.6-36.6), higher among boys (43.8%, 95%CI: 41.8-45.8) than girls (24.3%, 95%CI: 22.0-26.6) (P<0.001). 5882 (21.8%) students suffered from depression symptoms. After adjustment for socio-demographic status, lifestyle factors and academic performance, compared to students without engaging in MSE, the prevalence ratios (PRs) and associated 95% confidence intervals (95%CIs) for depression symptoms were 0.98 (0.97-0.99) for those engaging in MSE once a week, 0.95 (0.93-0.97) for 2 days/week, 0.93 (0.90-0.96) for 3 days/week, 0.90 (0.87-0.94) for 4 days/week, 0.88 (0.84-0.93) for 5 days/week, 0.86 (0.81-0.92) for 6 days/week, and 0.84 (0.78-0.90) for 7 days/week, respectively.

Conclusions:

The overall prevalence of meeting MSE recommendations in Zhejiang is low. Frequency of muscle-strengthening exercise was inversely associated with depression symptoms among adolescents.