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The current study examined effects, moderators (for whom), and mediators (working mechanisms) of 12 months of exercise on health-related quality of life (HRQoL) in older long-term survivors of prostate cancer.In total, 100 men aged 71.7 years (standard deviation, 6.4 years) were randomly assigned to 6 months of supervised aerobic and resistance exercise followed by 6 months of a home-based exercise maintenance program (EX group) or printed education material regarding physical activity for 12 months (PA group). Assessments took place at baseline and after 6 and 12 months. Generalized estimating equations were used to study the effects of EX versus PA on HRQoL at 6 and 12 months, adjusting for baseline HRQoL. The authors examined potential sociodemographic and clinical moderators by adding interaction terms, and potential physical and psychological mediators using the product-of-coefficients test.At 6 months, significant beneficial effects were found for global QoL, physical function, and social function in the EX group compared with the PA group. For physical function, beneficial effects were sustained at 12 months. Moderation analyses demonstrated larger effects of EX versus PA for patients who were married, started exercising sooner after their diagnosis, and previously used bisphosphonates. Changes in lower body functional performance significantly mediated the effect of EX on global QoL, physical function, and social function. No mediating effects on HRQoL were found for aerobic fitness, physical activity, fatigue, distress, or falls self-efficacy.Aerobic and resistance exercise appears to have beneficial effects on HRQoL among older, long-term survivors of prostate cancer. Effects were moderated by marital status, time since diagnosis, and use of bisphosphonates, and were mediated by lower body functional performance.

The objective of the current study was to identify mediators of the effects of a combined resistance and aerobic exercise program on perceived physical and general health in men undergoing androgen deprivation therapy for prostate cancer.In total, 57 patients with prostate cancer undergoing androgen deprivation therapy were randomly assigned to 12 weeks of resistance and aerobic exercise or usual care. The outcome measures of physical and general health were assessed by standardized questionnaires. Linear regression analyses were conducted on the residual change scores of the variables. The mediating effects of fatigue, muscle strength, and functional performance on the intervention's effect on physical and general health were examined using the product of coefficients method. Bootstrapping was used to calculate the 95% confidence intervals (95% CIs).The exercise intervention was found to significantly improve physical (beta, 5.03; 95% CI, 1.01-9.04) and general health (beta, 12.89; 95% CI, 2.24-23.54). Upper body muscle strength and walking speed significantly mediated the intervention effect on physical health (beta, 2.65; 95% CI, 0.64-5.54), accounting for 53% of the total effect. Walking speed and fatigue were found to be mediators in the intervention effect on general health (beta, 7.52; 95% CI, 2.16-16.92), accounting for 51% of the total effect.The intervention effects on physical and general health were explained by different mediating mechanisms. Walking speed mediated the intervention effect on both physical and general health. The intervention effect on physical health was further mediated by upper body strength, whereas the effect on general health was mediated by fatigue.