A portable exercise device which provides the benefits of working out with free weights. Adjustable foot pads on opposite sides of a central housing accommodate different stance widths and retract to a compact storage position. Right and left reels in the housing receive cords which extend through the foot pads and carry special hand grips. Outward pulling on the cords is resisted by spring packs having clock-type coil springs. The spring packs can be stacked on one another to vary the resistive force applied to the reels. The two resistance systems are independent of one another but are adjusted to the same initial tension by a common cable adjustment mechanism. Attachment of added components allows rowing exercises to be carried out.