Examining The Relationship Between Physical Activity And Depressive Symptoms: A Comparison Of Bouts Versus Every Minute Counts

PURPOSE: The 2018 Physical Activity (PA) Guidelines recommend at least 150 minutes of moderate-to-vigorous physical activity (MVPA) per week in which every minute counts towards the accumulation goal. This differs from the 2008 guidelines which recommended that PA be accumulated in at least 10-minute bouts. Few studies have examined how these guidelines differ with respect to mental health outcomes. We examined whether MVPA, light PA (LPA), or total PA (TPA) accumulated in at least 10-minute bouts differs from MVPA, LPA, or TPA accumulated per “every minute counts” with respect to depressive symptoms in a sample of non-clinically depressed older adults. METHODS: We used baseline data (N = 648) from the Investigating Gains in Neurocognition in an Intervention Trial of Exercise study. Participants scoring >9 on the Geriatric Depression Scale and exercising for greater than 20 min/day, three days per week were ineligible for participation in the trial. PA was measured using a wrist-worn accelerometer (Actigraph GT9X Link) over 7 days and processed using GGIR. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale (HADS-D). Linear regression models examined the relationship between MVPA, LPA, and TPA and depressive symptoms. Age, sex, and study site were added as covariates. RESULTS: 587 participants (Mean age = 70 ± 3.7; 70% female) had complete actigraphy data and were used in the analyses. Participants accumulated an average of 30 min/day of MVPA using “every minute counts” and 8 min/day in bouts. Using an “every minute counts” analysis, greater amounts of MVPA (β = -0.011, p = .01), LPA (β = -0.001, p = .04), and TPA (β = -0.001, p = .01) were associated with reduced depressive symptoms. However, when examining PA accumulated in at least 10-minute bouts, neither MVPA (β = -0.003, p = .2), LPA (β = 0.0007, p = .14), or TPA (β = 0.0008, p = .09) were associated with depressive symptoms. CONCLUSIONS: Our findings suggest that greater volume of overall PA, rather than the pattern in which it was accumulated, is related to reduced depressive symptoms among inactive older adults. This supports the 2018 PA Guidelines, recommending every minute counts towards the accumulation of PA, for the promotion of mood in late life. National Institutes of Health (R01AG053952)