Factors predicting gains in moderate-to-vigorous physical activity in prostate cancer survivors on androgen deprivation therapy.

Abstract

Whether individual, environmental, and psychosocial factors predict changes in moderate-to-vigorous physical activity (MVPA) is poorly addressed in prostate cancer (PC) survivors undergoing androgen deprivation therapy (ADT). This secondary analysis of a randomized controlled trial examined changes in MVPA following a supervised personal training (PT), supervised group-based (GROUP) program, or a home-based, smartphone-assisted exercise (HOME) intervention in PC survivors on ADT and explored individual, environmental, and psychosocial predictors of MVPA. PC survivors on ADT underwent aerobic and resistance training for 6months via PT, GROUP, or HOME. MVPA was captured via accelerometers and the Godin Leisure-Time Exercise Questionnaire. Changes in MVPA between groups were assessed using linear regression. The following predictors of MVPA were examined using Spearman correlations: the Neighborhood Environment Walkability Scale (NEWS); the Planning, Attitudes, and Behaviours (PAB) scale; the Relatedness to Others in Physical Activity Scale (ROPAS); and individual factors at baseline. Participants (n = 37) were 69.4 ± 6.5years old and 78.4% were on ADT for ≥ 3months. Changes in accelerometry-based bouts and MVPA as well as self-reported MVPA did not differ between groups at 6months. The Aesthetics domain of the NEWS questionnaire at baseline was the strongest predictor of positive MVPA changes (r = .66). Attitude (r = .64), planning (r = .57), and motivation (r = .50) at baseline were also predictive of engaging in higher MVPA throughout the intervention. Changes in objective MVPA were modest. Additional emphasis on specific psychosocial and individual factors is important to inform theory-based interventions that can foster PA behavior change in PC survivors on ADT. Registration # NCT02046837.