A pilot study on the motivational effects of an internet-delivered physical activity behaviour change programme in...

To examine the effects of an internet-delivered, distance-based physical activity (PA) behaviour change programme on motivation to perform PA in cancer survivors.

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.

Motivational variables from the TPB including intention, planning, attitude, subjective norm, perceived behavioural control and underlying beliefs.

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).

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.