Physical activity (PA) programmes that are targeted to align with participants' personally important motives may promote sustained levels of participation. Sport and exercise contexts may accommodate very different motivational needs Kilpatrick, M., Hebert, E., & Bartholomew, J. (2005). College students' motivation for physical activity PA: Differentiating men's and women's motives for sport participation and exercise. Journal of American College Health, 54, 87-94, and these differences may need to be considered in programming. This study examined differences in the importance of various participatory motives between sportspersons and exercisers, and whether certain motives differentially related to levels of PA commitment and lapses as a function of PA context. Participants (N = 252, M age = 47.2, range = 35-57 years) self-identified as either sportspersons (n = 108) or exercisers (n = 144) and completed a survey capturing their PA motives Markland, D., & Ingledew, D. K. (1997). The measurement of exercise motives: Factorial validity and invariance across gender of a revised Exercise Motivations Inventory. British Journal of Health Psychology, 2, 361-376, commitment and frequency of lapses. Although sportspersons rated competition and social-affiliation motives higher, overall results showed few differences between contexts. For sportspersons and exercisers alike, enjoyment, stress relief and social-affiliation motives predicted commitment, and health-related and stress relief motives buffered against odds of lapsing. Discussion focuses on how research might further examine contextual differences, as well as recommendations for how programmers might target PA programmes in line with significant motives that foster commitment and buffer against lapses.