Abstract: An isokinetic exercise device comprises in a linking arrangement first and second manually-operated members with a floating plate and brake assembly therebetween, all members mounted in rotation about a shaft member. A series of paired arcuate raceways, having a non-linear sloped profile, are located in the opposing faces of the floating plate and the first member. Captivation of a ball bearing between the raceways presents a driving connection for transmittal of forces, created by operator rotation of the first and second members, to the brake assembly. The brake assembly responds to such forces to retard rotation of the first and second members linked thereto, such retardation presented as a resistance to the user. A speed selector assembly provides for a selectable change in the location and attitude of the driving connection so as to control the efficacy of the driving connection which changes the degree of forces transmitted to the brake assembly.