member 522 of the linear actuator 50 is located at the base portion of the transmission shaft 521 the urging frame 40 and the two pull rods 60 are almost horizontally disposed between the jogging platform 30 and the base 10 in light of this state the front segment of the jogging platform 30 is accommodated between the two base rods 11 of the base 10 such that the underside of the midsegment of the two side rods 31 is rested against the rear connection rod 12 the jogging platform 30 is in the horizontal state the user stands on the jogging belt 33 of the jogging platform and then starts the electric motor 341 to drive the jogging belt 31 so as to enable the user to begin the jogging exercise as shown in fig7 9 the user may raise the jogging platform 30 to be in the state of angle of elevation to enhance the exercise energy by starting the linear actuator 50 as to cause the transmission shaft 521 to turn forward thereby causing the driven member 522 to move toward the end of the transmission shaft 521 the input member 44 is thus actuated to turn the entire urging frame 40 to swivel downward to enable the rollers 45 to slide toward the rear end of the guide slots 111 by means of the guidance of the two pull rods 60 the urging frame 40 pushes the front segment of the jogging platform 30 to rise.