title: Higher-intensity exercise helps cancer survivors remain motivated.
abstract: The aim of the present study was to determine if exercise intensity impacts upon the psychosocial responses of breast and prostate cancer survivors to a rehabilitation program.
  
  
  
  Eighty-seven prostate and 72 breast cancer survivors participated in an 8-week exercise and supportive group psychotherapy intervention (n = 84) or control (n = 75) group. Intervention participants were randomized to low-to-moderate intensity exercise (LIG; n = 44; 60-65 % VO2peak, 50-65 % one repetition maximum (1RM)) or moderate-to-high intensity exercise (HIG; n = 40; 75-80 % VO2peak, 65-80 % 1RM) while controls continued usual care. Before and after the 8 weeks, all participants completed the Functional Assessment of Cancer Therapy-Breast or -Prostate to assess quality of life (QOL) and Behavioural Regulations of Exercise Version 2 for exercise motivation. Intervention participants also completed a follow-up assessment 4 months post-intervention.
  
  
  
  All three groups improved in QOL from baseline to post-intervention, with no significant differences. From post-intervention to follow-up, the LIG and HIG similarly maintained QOL scores. Between baseline and post-intervention, both intervention arms improved their motivation to exercise compared to the controls (p = 0.004). At the 4-month follow-up, the HIG had maintained their overall exercise motivation (p < 0.001) and both domains of intrinsic motivation (identified regulation, p = 0.047; intrinsic regulation, p = 0.007); however, the LIG had regressed.
  
  
  
  The structured intervention was successful at improving autonomous exercise motivation, regardless of exercise intensity. However, only those participants who had exercised at a higher intensity sustained their improvement. Intervention participation did not improve QOL more than controls.
  
  
  
  Higher-intensity exercise is more likely to result in more sustainable increases in motivation to exercise among cancer survivors.
authors.affiliation: Department of Kinesiology, California State University-Monterey Bay, Seaside, CA, USA. ermartin@csumb.edu.|School of Health Sciences, University of Notre Dame Australia, Fremantle, Australia. ermartin@csumb.edu.|, 100 Campus Center, Seaside, CA, 93955, USA. ermartin@csumb.edu.
authors.forename: Eric
authors.initials: E
authors.lastname: Martin
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.|Lineberger Comprehensive Cancer Center, Chapel Hill, NC, USA.
authors.forename: Claudio
authors.initials: C
authors.lastname: Battaglini
authors.affiliation: Institute for Health Research, University of Notre Dame Australia, Fremantle, Australia.
authors.forename: Beth
authors.initials: B
authors.lastname: Hands
authors.affiliation: School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia.
authors.forename: Fiona L
authors.initials: FL
authors.lastname: Naumann
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009369:Neoplasms / Q000523:psychology / Q000534:rehabilitation*; D011613:Psychotherapy; D011788:Quality of Life; D017741:Survivors / Q000523:psychology*
keywords: Breast cancer; Exercise motivation; Exercise oncology; Prostate cancer; Quality of life