Ni, M and Signorile, JF. High-speed resistance training modifies load-velocity and load-power relationships in Parkinson's disease. J Strength Cond Res 31(10): 2866–2875, 2017—Muscle power is a major neuromuscular factor affecting motor function and independence in patients with Parkinson's disease (PD), and it is commonly targeted using high-speed exercise. This study examined the changes in velocities (Vpp) and percent loads (%1RMpp) at peak power and load-velocity (L-V) and load-power (L-P) relationships, resulting from resistance training because of exercise choice and loading in older patients with PD. Fourteen older adults with mild to moderate PD participated in a 12-week randomized controlled power training trial. Changes in L-V and L-P relationships for the biceps curl, chest press, leg press, hip abduction, and seated calf were assessed using pneumatic resistance machines at loads ranging from 30 through 90% of subjects' 1 repetition maximum for each exercise. Significant increases in Vpp were seen for biceps curl, leg press, hip abduction, and seated calf and decreases in %1RMpp were noted for biceps curl and hip abduction. Additionally, unique patterns of change were seen in these relationships across exercises, with biceps curl, chest press, and leg press showing the greatest shifts at the lower load end of the loading spectrum, and hip abduction and seated calf showing greatest responses at the higher end. The patterns of change in L-V and L-P relationships provide evidence for the unique responses of the specific muscle groups and joints to the exercises evaluated and offer a framework for more exacting exercise prescriptions in patients with PD.