BackgroundStudies argue that knowledge about motives for physical activity participation can inform activities, initiatives and interventions to promote physical activity. However, most of these studies are based on small sample sizes and only include participants within a few selected types of PA. Further, they have not examined the consistency of individuals’ motives across different activity types. As a result, this article examines RQ1: the most prevalent motives, RQ2: the association of motives with activity type and social background characteristics, and RQ3: the consistency of motives across different activity types.MethodsWe utilised data from a survey of physical activity participation among 163,000 adult Danes (aged 15 + years). In the survey, the participants were asked about their participation in thirteen activity types and about their motives for practising the activity types they reported to do at least weekly. The motive items were operationalised based on the eight dimensions in the Physical Activity and Leisure Motivation Scale (PALMS). We conducted analyses of mean values and standard deviations as well as multilevel regression analyses.ResultsWe identified large differences in the importance of different motives for physical activity participation. The three most important motives were psychological condition (M = 4.54), physical condition (M = 4.48) and enjoyment (M = 4.36). We also found significant associations between motives and activity types in particular, but also between motives and social background characteristics (gender, age and educational level). For instance, we found that compared to running, physical condition was a much less important motive in outdoor activities (b = -3.01), activities on water (b = -2.44) and street sports (b = -2.38). Finally, our analysis showed how individuals’ motives are not consistent across different activity types.ConclusionsOur study contributes to the literature on motives for physical activity participation by using a large sample of individuals and by differentiating motives according to a wide range of activity types. The results underline the need to study motives in relation to activity types, as there are large differences in the prevalence of different motives. Our findings suggest that motives are not consistent across activity types, but rather they develop in an interplay between the individual and the activity type practised.