Research suggests that individuals with autism live a lower quality of life than their peers. Individuals with autism are more likely to become obese than their typically developing peers, and less likely to develop friendships and be involved in their communities. While physical fitness service providers are experts in physical fitness, working with individuals with autism can require additional teaching skills. This study will investigate the effectiveness of instructor implemented Positive Behaviour Support for young adults with autism in a physical fitness program. It is anticipated that the Canucks Autism Network will benefit from this study through the demonstration of the effectiveness of their instructor training and fitness program. The instructors in the study are anticipated to develop skills to work with individuals with autism, which they can further apply in their practice. Participants in the study are anticipated to experience health and social benefits from participating in the program.