Regular exercise is associated with many health-related benefits including improvement in heart and lung functioning, sleep patterns, and mood. Improving health through physical activity also decreases the demand placed on the health care system. Unfortunately, adhering to an exercise program can be very difficult, particularly for older adults. Older adults face more chronic health problems, are more susceptible to social isolation and withdrawal, and are more likely to be hindered by age-related stereotypes regarding physical activity. Given the gradual population shift of the “baby boomers” into this age group, the importance of enhancing the adherence of older adults to exercise programs becomes acutely apparent. Research has sought to examine what social and environmental factors are likely to engage and sustain the involvement of seniors in physical activity. Studies suggest that older adults prefer to exercise with others of a similar in age, and generally dislike exercising in groups composed of young and middle aged adults. Although the perceived age of others may be one important characteristic, it is likely that other perceptions of the group environment may similarly influence older adults' motives and exercise adherence behaviours. William Dunlop is further exploring the relationship between older adults' perceptions of group member characteristics and their subsequent motivation and adherence to group exercise programs. He will study exercise groups at community and health centres across British Columbia’s lower mainland, characterizing them by the surface-level traits of the group (age, gender, ethnicity) as well as the deep-level traits of members (e.g., attitudes, beliefs and values). By identifying how the composition of exercise groups influences the adherence behaviours of group members, Dunlop hopes his work will contribute to the development of intervention-based studies that more effectively increase the physical and psychological health of older adults.