Association between depressive symptoms and perceived exertion during exercise: observational population-based cohort study of European,Indian Asian,and African-Caribbean older adults

BackgroundExercise interventions are increasingly recognised to help reduce depressive symptoms; however, fatigue and perception of increased energy expenditure, which are often associated with depression, may be barriers to adherence. Although depression has been associated with a blunted cardiovascular stress response, little evidence exists describing perceived exertion during exercise and depression. Furthermore, cardiorespiratory fitness and depression vary by ethnicity across a range of ages. We investigated associations between depressive scores and perception of exertion and physiologically measured exertion during exercise in a tri-ethnic population of older adults.MethodsParticipants were older adults enrolled in a tri-ethnic population-based cohort originally recruited in west London (UK), the Southall and Brent REvisited (SABRE) study. 691 participants (57% men, 43% women; mean age 71·3 years, SD 6·5 years; ethnicity European n=304], Indian Asian n=222], or African-Caribbean n=165]) underwent assessment of depression on the ten-item Geriatric Depression Scale (GDS) and undertook a self-paced 6-min step test. Outcomes measured were rate of perceived exertion (assessed using a 0–10 Borg score immediately after exercise) and exertion (steps completed and highest achieved whole-body oxygen consumption in mL/min per kg). Linear relationships were summarised using β-coefficients with 95% CI from regression models adjusted for age, sex, and ethnicity. An interaction term was used to assess the effect of ethnicity on associations. Ethics approval was from the National Research Ethics Service Committee Fulham, London. All participants gave written consent to undertake the tests.FindingsIn all participants, higher rate of perceived exertion was associated with greater GDS (β 0·10, 95% CI 0·01 to 0·19, p=0·03). GDS was inversely associated with objectively measured exertion (β ?6·8, 95% CI ?9·9 to ?3·8 for steps, p<0·001; and ?7·0, ?10·0 to ?4·0 for whole-body oxygen consumption, p<0·001). The effect of GDS on rate of perceived exertion persisted following adjustment for steps achieved during the test (adjusted β 0·12, 95% CI 0·02 to 0·21, p=0·01) or whole-body oxygen consumption (0·14, 0·05 to 0·25, p=0·01). Ethnicity did not modify these associations.InterpretationOlder adults with higher depression scores had an increased perception of exertion independent of objectively measured exertion during exercise. This result is consistent with previous findings and a well-documented blunted cardio-respiratory response to exercise in the presence of depression. Greater perceptions of exertion could hinder compliance in exercise training programmes targeting depressive symptoms in older adults.FundingThe SABRE study was funded by a grant from the British Heart Foundation.