Abstract: An exercise devise that simulates cross country skiing. A pair of rails are mounted between pivotable handles simulating ski poles. Foot pads slidably mounted on the rails are interconnected by a loop including a flexible strap that extends along each rail and around curved static bearing surfaces at each end. A spring maintains the strap of the loop tightly against the static bearing surfaces to generate resistance to sliding movement of the foot pads. The tension in the spring is adjustable by a tightener that shortens the length of the loop and thereby tightens the strap against the static bearing surfaces.