Exercise apparatus, for example of the type disclosed in the U.S. Pat. No. 6,705,976, is provided with a resistance source for exerting a counterforce to the force applied by the user. This resistance source includes at least two of (1) means, such as a cylindrical rod or the like, for removably holding one or more weights, (2) at least one hook or the like for removably attaching one or more springs, and (3) means for removably attaching one or more damping devices.