A housing 1 is provided with a left foot support 2a and a right foot support 2b respectively for mounting users left foot and right foot. The left foot support 2a and the right foot support 2b are respectively driven to move along a rail which defines a travel path. The housing 1 is provided with a motor 31 having an output shaft 31 a which generates a rotary motion which is distributed into two routes by a worm gear 32a and two worm wheels 32b. Rotary motions of each of the worm wheels 32b are respectively transmitted to the left foot support 2a and the right foot support 2b by a crank rod 38, thereby the rotary motions of each of the worm wheels 32b act as driving forces which respectively reciprocate the left foot support 2a and the right foot support 2b. Accordingly, this configuration makes it possible to provide an exercise assisting device being configured to stimulate leg muscles by only one driving force for generation of the driving forces.
