Body exercise device including: seat portion having a seat face a pair of left and right airbags and/or a pair of front and rear airbags causing the seat face of the seat portion to be left-right or front-rear inclined an air supply unit that supplies pressurized air to an airbag air supply/discharge switching unit that switches between supplying air to and discharging air from an airbag pressure detection unit that detects pressure in an airbag and balance determination unit that, in a process of supplying air to or discharging air from the right and left or front and rear airbags according to the switching operation of the air supply/discharge switching unit, determines the left-right or front-rear balance state of the user based on a difference in pressure change in the pair of left and right airbags or the pair of front and rear airbags, detected by the pressure detection unit.
