A total-body exerciser comprises: an upper-body exercising unit; a buttocks exercising unit; and an ankle exercising unit. The upper-body exercising unit comprises: an upper-body support for supporting the upper body; an upper-body supporting guide rail formed on the bottom surface of the upper-body support and enabling the upper-body support to move horizontally; and a rotating bracket mounted on a lower surface of the upper-body supporting guide rail. The buttocks exercising unit comprises: a buttocks support for supporting the buttocks; and a buttocks-supporting height-adjusting cylinder connected to a lower portion of the buttocks support, and capable of adjusting the height of the buttocks support. The ankle exercising unit comprises: an ankle support for supporting an ankle; an ankle-supporting guide rail formed on a bottom surface of the ankle support and enabling horizontal movement of the ankle support; and a rotating bracket mounted on a lower surface of the ankle-support guide rail.