Exercise-related goals and values are likely to differ between people based on factors such as gender, age and culture, and there are reasons to believe that the mechanisms between motivation and exercise behavior presented in the self-determination theory (SDT) process model also could vary as a function of such influences.

This study is part of a digital exercise intervention (see Weman-Josefsson et al., 2016) in a sample of 318 adult women (n = 278) and men (n = 40) aged 23-67 years (M = 46.7; SD = 9.4) joining a digital work-site based step contest. Behavioral regulations, psychological need satisfaction and exercise behavior was measured using a three wave web based questionnaire (T1 = baseline; T2 = post-intervention, week 3; and T3 = follow up, week 6). Moderation analyses were done in the SPSS macro PROCESS using a bootstrapping resampling approach.

The moderation analyses showed gender and age differences in the relations of behavioral regulations, psychological need satisfaction and exercise behavior within the SDT process model. Controlled motivation was for example a significant positive predictor for exercise in men showing external regulation at T2 to moderate the relation between psychological need satisfaction and exercise in men (beta = 11.29, p < .01) at T3 in appositive direction, while this path was negative and non-significant for women. Also Intrinsic regulation at T2 positively predicted relatedness need satisfaction for women at the same time-point (beta = 0.47, p < .05), but this path was negative and non-significant for men. In terms of age differences, the negative association between external regulation at T2 and strenuous exercise at T3 was stronger and significant for older adults compared to middle-aged adults (beta = -8.90, p < .01) and was positive (but non-significant) for younger adults.

We found gender and age to moderate several paths of the self-determination process model, suggesting more comprehensive analyses of potential moderators in exercise behavior to be an interesting avenue for future studies.