title: Associations of objectively measured moderate-to-vigorous physical activity and sedentary behavior with quality of life and psychological well-being in prostate cancer survivors.
abstract: Although evidence is building on the positive effects of physical activity for prostate cancer survivors, less is known about the possible independent effects of sedentary behavior on quality of life and psychological well-being in this population. We determined the extent to which objectively measured moderate-to-vigorous physical activity (MVPA) and sedentary behavior were independently associated with quality of life, anxiety, and depressive symptoms in prostate cancer survivors.
  
  
  
  An exploratory cross-sectional analysis was undertaken on baseline data from a multicenter, cluster randomized controlled trial on the efficacy of a clinician referral and 12-week exercise program for men who had completed active treatment for prostate cancer. Multiple regression analyses were performed using data from 98 prostate cancer survivors who wore hip-mounted accelerometers (time spent sedentary defined as <100 counts per minute [CPM]; MVPA defined as >1,951 CPM) and completed self-report instruments on their quality of life, anxiety, and depressive symptoms. Results were compared with minimal clinically important differences for the quality of life scales.
  
  
  
  Independent of sedentary behavior, increases in MVPA of between 15 and 33 min/day were associated with clinically important (but not statistically significant) improvements in three quality of life scales (insomnia, diarrhea, and financial difficulties). Independent of MVPA, decreases in sedentary behavior of 119 and 107 min/day were associated with clinically important (but not statistically significant) improvements in physical functioning and role functioning, respectively.
  
  
  
  Within our exploratory study, modest increases in MVPA and more substantive decreases in sedentary behavior were independently associated with clinically important improvements in several quality of life scales. Further research, including prospective studies, is required to understand sedentary behavior across larger and more representative samples (in terms of their physical, psychological, and social functioning and their engagement in physical activity) of prostate cancer survivors.
  
  
  
  Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12610000609055.
authors.affiliation: Deakin University, Faculty of Health, Locked Bag 20001, Geelong, VIC, 3220, Australia.
authors.forename: Cadeyrn J
authors.initials: CJ
authors.lastname: Gaskin
authors.affiliation: Deakin University, Faculty of Health, Locked Bag 20001, Geelong, VIC, 3220, Australia.|Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia.
authors.forename: Melinda
authors.initials: M
authors.lastname: Craike
authors.affiliation: Deakin University, Faculty of Health, Biostatistics Unit,, Geelong, Australia.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Mohebbi
authors.affiliation: Deakin University, School of Exercise and Nutrition Sciences, Geelong, Australia.
authors.forename: Jo
authors.initials: J
authors.lastname: Salmon
authors.affiliation: Behavioural Medicine Laboratory, Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada.
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.affiliation: School of Health and Human Sciences, Southern Cross University, Lismore, NSW, Australia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Broadbent
authors.affiliation: Deakin University, Faculty of Health, Locked Bag 20001, Geelong, VIC, 3220, Australia. trish.livingston@deakin.edu.au.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Livingston
mesh_terms: D000368:Aged; D001007:Anxiety / Q000523:psychology; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology; D015444:Exercise / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010549:Personal Satisfaction; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000523:psychology*; D011788:Quality of Life / Q000523:psychology*; D057185:Sedentary Behavior; D057566:Self Report; D017741:Survivors / Q000523:psychology*
keywords: Accelerometer; Exercise; Physical activity; Prostate cancer; Sedentary behavior; Sedentary time