PURPOSE - 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.
METHODS - 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.
RESULTS - 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.
CONCLUSIONS - 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.
IMPLICATIONS FOR CANCER SURVIVIORS - Higher-intensity exercise is more likely to result in more sustainable increases in motivation to exercise among cancer survivors.
Journal of cancer survivorship : research and practice. 2015 Nov 19 [Epub ahead of print]
Eric Martin, Claudio Battaglini, Beth Hands, Fiona L Naumann
Department of Kinesiology, California State University-Monterey Bay, Seaside, CA, USA. Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. , Institute for Health Research, University of Notre Dame Australia, Fremantle, Australia. , School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia.