Sa˝udo, B, de Hoyo, M, and McVeigh, JG. Improved muscle strength, muscle power, and physical function after flywheel resistance training in healthy older adults: A randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to examine whether flywheel resistance exercise training improved muscle strength, muscle power, and physical function in older adults. Thirty-six older adults (64 ▒ 5 years) were randomly allocated to either a flywheel resistance exercise training group (ETG; n = 18) or a control (CON) group (n = 18). Subjects in the ETG underwent 6 weeks of resistance training on a flywheel squat device (4 sets of 9 maximal repetitions). Isokinetic concentric (60 and 240░Ěs) and eccentric (120░Ěs) knee extension and flexion peak torques and mean power were measured. Physical function was assessed by the 30-second Chair Sit-Stand Test (CST) and walking speed. After the intervention, within-group analyses showed significantly greater flexion torques and mean power with the dominant leg (concentric at 60░Ěs and 240░Ěs and eccentric at 120░Ěs; all d > 0.7, p < 0.05) and improvements in CST (d > 0.8) in the ETG, while no substantial differences were found in the CON group. Significant between-group differences in knee flexion torque both concentric (at 60░Ěs: ┐ = 0.168 and 240░Ěs: ┐ = 0.112) and eccentric (at 120░Ěs: ┐ = 0.103) with the dominant leg were also found in favor of the ETG. There was also significantly better performance in the CST for the ETG (┐ = 0.207). There was a significant association between changes in strength and changes in mean power in the ETG. Changes in physical function outcomes were also observed. In conclusion, flywheel resistance exercise training is an appropriate form of activity for improving strength and functional capacity of older adults.