Classes and Data-Collection for the GOAL Trial finished successfully As of August 2015, the classes and data-collection for the GOAL Trial have finished successfully. From March to August 2014 and 2015 close to 600 female and male older adults participated in thrice weekly exercise sessions lead by a group of fabulous volunteer instructors at three YMCA locations across Greater Vancouver. The UBC Research Team sincerely thanks all participants, instructors, and YMCA personnel for their time, effort, and cooperation and is looking forward to share the study results as soon as possible. Why Groups? Physical activity conducted in a group-setting has the potential to provide older adults with an opportunity to develop a sense of social connectedness. A number of physical activity interventions have been developed to increase physical activity. Group dynamics-based programs are often more successful than those that focus on individuals. Group-based programs have been able to increase physical activity across a variety of populations (older adults, postnatal women), but less is known about why these groups are so effective. This study aims to investigate the influence of both mixed and same gender exercise classes for older adults. Fit Fellas Legacy The age- and gender-matched exercise programs examined in this study were informed by a highly successful exercise program entitled the ‘Fit Fellas’. Fit Fellas was developed for older adult males in British Columbia over 20 years ago for "guys to be guys" and to stay active as they approached retirement age. Over 45% of the members have been adherent for over 10 years and 70% have been adherent for over 5 years. The primary outcome to be assessed within this trial will be older adults’ physical activity adherence behaviours (over 3 months and 6 months). Secondary outcomes to be assessed within this study include group cohesion, and affective attitudes (enjoyment), which will be assessed as mediators of adults’ adherence behaviour. This project could not be conducted without the hard work and help of the Fit Fellas. A special thanks to Barrie Chapman for his involvement with the session development, his voluntary leadership, and all his time and energy to continue the Fit Fellas legacy.