The aim of this study was to examine the effects of Assisted Cycle Therapy (ACT) on self-efficacy and exercise perception in older adults with Down syndrome (DS) after a three times a week for 8 weeks intervention. Thirteen participants were in the ACT group in which a motor assisted their cycling to be performed at least 30% faster than voluntary cycling (VC), 11 participants were in the voluntary cycling group and two participants were in the no cycling (NC) group. The results showed that both exercise groups (i.e., ACT and VC) improved in their self-efficacy after the 8 week intervention. In addition, exercise perception improved following ACT and not VC or NC. Our results are discussed with respect to their future implications for exercise in the DS population. It might be that the yielded results were due to differences in effort required by each intervention group as well as the neurotrophic factors that occur when muscle contractions create synaptic connections resulting in improvement in cognition and feelings of satisfaction. In the future, research should focus on the psychological factors such as social accountability and peer interaction as they relate to ACT and physical activity in person's with DS.