Background: Improving sleep quality and reducing depressive symptoms may be target mechanisms for intervention-based research aimed at reducing cardiometabolic risk in low-income communities. This study assessed the effects of exercise training on depressive symptoms and sleep in obese women for a low socioeconomic community. The secondary aim explored associations between changes in depressive symptoms and sleep with changes in cardiorespiratory fitness and cardiometabolic risk factors. Methods: Participants were randomized into exercise (n = 20) or control (n = 15) groups. The exercise group completed 12 weeks of combined resistance and aerobic training (40–60 min, 4 d/wk), and the control group maintained habitual diet and activity. Preintervention and postintervention testing included questionnaires on symptoms of depression, psychological distress, and sleep quality. Sedentary time, peak oxygen consumption, body mass index, and insulin sensitivity were measured objectively. Sleep duration (accelerometry) was assessed at preintervention and weeks 4, 8, and 12. Results: Exercise training reduced depressive symptoms (P = .002) and improved sleep quality (P < .001) and sleep efficiency (P = .005). Reduced depressive symptoms were associated with improved peak oxygen consumption (rho = −.600, P < .001), and improved sleep quality correlated with reduced sedentary time (rho = .415, P = .018). Conclusion: These results highlight the potential for community-based exercise interventions to simultaneously address multiple comorbidities in a low-income setting.
Amy E. Mendham, Julia H. Goedecke, Melony C. Fortuin-de Smidt, Lindokuhle Phiri, Louise Clamp, Jeroen Swart, Gosia Lipinska, and Dale E. Rae
Amy E. Mendham, Julia H. Goedecke, Nyuyki Clement Kufe, Melikhaya Soboyisi, Antonia Smith, Kate Westgate, Soren Brage, and Lisa K. Micklesfield
Background : We first explored the associations between physical behaviors and total and regional adiposity. Second, we examined how reallocating time in different physical behaviors was associated with total body fat mass in men and women from a low-income South African setting. Methods : This cross-sectional study included a sample of 692 participants (384 men and 308 women) aged 41–72 years. Physical behaviors were measured using integrated hip and thigh accelerometry to estimate total movement volume and time spent in sleeping, sitting/lying, standing, light physical activity, and moderate to vigorous physical activity (MVPA). Total body fat mass and regional adiposity were measured using dual-energy X-ray absorptiometry. Results : The associations between total movement volume and measures of regional obesity were mediated by total body adiposity. In men, reallocating 30 minutes of sitting/lying to 30 minutes of MVPA was associated with 1.0% lower fat mass. In women, reallocation of 30 minutes of sitting/lying to MVPA and 30 minutes of standing to MVPA were associated with a 0.3% and 1.4% lower fat mass, respectively. Conclusions : Although the association between physical behaviors and fat mass differed between men and women, the overall public health message is similar; reallocating sedentary time to MVPA is associated with a reduction in fat mass in both men and women.