People with Parkinson disease will be recruited from the community and randomized into 2 equal groups: high intensity interval circuit training with lower extremity (LE) and lower and upper extremity (LEUE) training. The study will be composed of a baseline assessment, 8 group class sessions, and a post-intervention assessment. The baseline assessment will include demographics, disease and fall history and outcome measure collection. Group class sessions will include concurrent group warmup, followed by an 8-station circuit performed with high intensity intervals, and a cool-down. The circuit will include 4 stations performed by both the LE and LEUE groups and 4 stations specific to each intervention group, including 4 additional LE exercise stations for the LE group and 4 UE specific stations for the LEUE group. The stations that differ will not be adjacent to one another nor specifically indicated as different. The stations that differ will mirror similar aspects of function (ie, strength, reaction time, etc.) for the UE and LE stations. Participants will be told exercise stations may vary within-session and week to week but will not be informed that only one group has UE exercise interventions. After conclusion of the class series, post-intervention balance and stepping outcomes will be reassessed.
