A wedge-shaped tilt provider is attached in contact with the bottom surface of a seat and the upper surface of a seat connection member of a rocking mechanism to set the seat to an initial inclined position relative to a reference position. By setting the seat to a forwardly inclined position from a horizontal position where the seated surface of the seat is set horizontal, the user straddling the seat can increase the amount of muscle activity of his or her rectus muscle of abdomen, or abdominal muscle. Further, by setting the seat to a rearwardly inclined position, the user straddling the seat can increase the amount of muscle activity of his or her back muscle such as paraspinal muscle. With use of a rocking type exercising apparatus having the above construction, a stress of exercise simulating horseback riding is given to the user by changing the position of the seat relative to the reference position by a certain degree of inclination, while rocking the seat which the user straddles, whereby the user is selectively provided with an exercising effect onto a specific site of his or her body.