PURPOSE The purpose of this study was to investigate the association of physical activity level with insomnia severity (Normal, Subthreshold, Moderate and Severe) in adolescents and to use it as a basis for insomnia prevention. METHODS This study was conducted on a cohort of 50 adolescents under the age of 20 (19 males, 31 females) recruited from Hospital N in Incheon, Korea. Participants were categorized into groups according to the severity of insomnia in both males and females using the Korean version of the Insomnia Severity Index-Korean (ISI-K). The Korean version of the International Physical Activity Questionnaire was also used to calculate participants’ weekly moderate and vigorous physical activity. RESULTS The participants’ characteristics did not differ by insomnia severity in males, but there were significant differences in weight (p=.008), BMI (p=.019), SBP (p=.004), and DBP (p=.019) in females by insomnia severity. In male adolescents, there was no significant difference in the amount of physical activity by insomnia severity, but there was a trend toward decreased amount of physical activity with increasing severity. Among female adolescents, there were significant differences in the amount of physical activity by insomnia severity: moderate (p<.05), high (p<.05), and moderate-high (p<.05). In the unadjusted model, adolescents who did not meet the recommended amount of physical activity (150 minutes per week) were more likely to have insomnia (OR=4.67, 95% CI=1.34–16.24) than those who met the recommended amount of physical activity. The model after adjusting for covariates (gender and body mass index) also showed an association between the recommended amount of physical activity and insomnia (OR=3.94, 95% CI=1.17–13.28). Negatice correlations was found between insomnia index and moderate-to-vigorous physical activity (r=–.357, p=.013). CONCLUSIONS Adolescents are approximately 4.67 times more likely to suffer from insomnia if they do not meet physical activity recommendations, and there was a negative correlation between the insomnia index and moderate-to-vigorous physical activity, suggesting that physical activity should be increased to reduce the insomnia index.
