title: The effect, moderators, and mediators of resistance and aerobic exercise on health-related quality of life in older long-term survivors of prostate cancer.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, EMGO Institute for Health and Care Research, Amsterdam, The Netherlands.
authors.forename: Laurien M
authors.initials: LM
authors.lastname: Buffart
authors.affiliation: Edith Cowan University Health and Wellness Institute, Edith Cowan University, Joondalup, Western Australia, Australia.
authors.forename: Robert U
authors.initials: RU
authors.lastname: Newton
authors.affiliation: Department of Public and Occupational Health, VU University Medical Center, EMGO Institute for Health and Care Research, Amsterdam, The Netherlands.
authors.forename: Mai J
authors.initials: MJ
authors.lastname: Chinapaw
authors.affiliation: Edith Cowan University Health and Wellness Institute, Edith Cowan University, Joondalup, Western Australia, Australia.|School of Medicine, University of Wollongong, Wollongong, New South Wales, Australia.
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Taaffe
authors.affiliation: Edith Cowan University Health and Wellness Institute, Edith Cowan University, Joondalup, Western Australia, Australia.|Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.|Faculty of Medicine, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: Nigel A
authors.initials: NA
authors.lastname: Spry
authors.affiliation: School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia.|Newcastle Mater Hospital, Newcastle, New South Wales, Australia.
authors.forename: James W
authors.initials: JW
authors.lastname: Denham
authors.affiliation: Edith Cowan University Health and Wellness Institute, Edith Cowan University, Joondalup, Western Australia, Australia.|Department of Surgery, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Joseph
authors.affiliation: Department of Pathology and Molecular Medicine, University of Otago, Wellington, New Zealand.
authors.forename: David S
authors.initials: DS
authors.lastname: Lamb
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, EMGO Institute for Health and Care Research, Amsterdam, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Brug
authors.affiliation: Edith Cowan University Health and Wellness Institute, Edith Cowan University, Joondalup, Western Australia, Australia.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Galvão
mesh_terms: D000368:Aged; D015444:Exercise; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000401:mortality / Q000523:psychology*; D011788:Quality of Life; D017741:Survivors / Q000523:psychology*
keywords: exercise; health-related quality of life; mediator; moderator; neoplasm