Abstract
Objective: To examine the effects of an internet-delivered, distance-based physical activity (PA) behaviour change programme on motivation to perform PA in cancer survivors.
Design: Breast, prostate and colorectal cancer survivors (N = 95) were randomized to either an online Theory of Planned Behaviour (TPB)-based PA behaviour change programme (UCAN) or usual care.
Main Outcome Measures: Motivational variables from the TPB including intention, planning, attitude, subjective norm, perceived behavioural control and underlying beliefs.
Results: UCAN had significant negative effects on self-efficacy (−.7; 95% CI = −1.2 to −.1; d = −.53, p = .019), affective attitude (−.4; 95% CI = −.8 to −.0; d = −.45, p = .044), instrumental attitude (−.5; 95% CI = −.9 to −.1; d = −.43, p = .026) and confidence to perform PA in bad weather (−.8; 95% CI = −1.6 to −.1; d = −.49, p = .030), despite health issues (−.7; 95% CI = −1.3 to −.1; d = −.48, p = .031), despite pain/soreness (−.7; 95% CI = −1.4 to −.1; d = −.52, p = .020), despite family responsibilities (−1.0; 95% CI = −1.7 to −.3; d = −.62, p = .005) and when PA is boring (−.8; 95% CI = −1.4 to −.1; d = −.54, p = .016).
Conclusion: UCAN had negative effects on motivational variables in cancer survivors. These findings may be explained by methodological issues related to measuring motivation and/or the absence of post-intentional constructs.
Disclosure statement
The authors declare that they have no competing interests.