Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

M.S. in Health Promotion


Health, Exercise Science, and Recreation Management

First Advisor

Paul D. Loprinzi

Second Advisor

Kofan Lee

Third Advisor

Toshiikazu Ikuta

Relational Format



Objective: To experimentally examine whether increasing sedentary behavior, among a young adult active population, for one week is still associated with increased depression symptomology even when allowing for a moderate engagement in physical activity (PA). Methods: Participants were confirmed as active via self-report and accelerometry during baseline and randomly assigned to one of three experimental groups. The Sedentary Intervention Group (n=19) reduced steps to less than 5000/day and were not alloto exercise for one-week; the Reduced MVPA (moderate-to-vigorous PA) Group (n=18) reduced steps to less than 5000/day but exercised for 50% of their previously reported vigorous PA for one-week; and the Control Group (n=20) maintained normal activity for one-week. PA and depression levels were assessed at baseline, postintervention, and after one week of resumed normal activity for the intervention groups. Results: The experiment was successful in altering physical activity levels among the intervention groups and maintaining activity habits in the control group (FInteraction =16.053, P < 0.001, ?2p¬ = 0.391). Depression symptomology remained constant across the two time periods in the control group. For both intervention groups (Sedentary Group and Reduced MVPA Group), depression statistically significantly increased during the inactive week and then resumed back to baseline levels after a week of resumed activity. However, there were no differential trends in depression (FInteraction = 0.276, P = 0.760, ?2p¬ = 0.008) among these two intervention groups. Conclusion: We provide experimental evidence that increasing sedentary behavior causes an increase in depression symptomology among young active adults. We did not, however, observe a joint effect of sedentary behavior and exercise on changes in depression.



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