[Purpose] This study determined the effects of age, gender, and participation on the benefits of a 6-month supervised exercise program on older adults. [Subjects and Methods] Eighty-five (37 women, 48 men) community-dwelling older adults participated. The chair sit-and-reach test, the 8-foot up-and-go test, the 6-minute walk test, the Berg Balance Scale, lower-body flexibility, dynamic balance, aerobic endurance, balance, metabolic rate, muscle strength, and position sense were evaluated. Repeated-measures of analysis of variance was performed including dependent variables of age, gender, and participation in the exercise program as dependent inter-subject factors and time of assessment as an intra-subject factor. [Results] Mean exercise participation was 29.88 ± 1.29 sessions. Flexibility, balance, position sense, and strength showed a significant main effect of time. There was a significant gender interaction for right shoulder flexion strength and knee extension strength, a significant gender-participation interaction for pre-/post-intervention measures of functional mobility, and a significant age-participation interaction for flexibility. [Conclusion] Exercise training improved outcomes after 6 months of supervised exercise, but the changes were similar regardless of participation level. Changes in strength were more pronounced in men than women.