To facilitate a method for building up muscle by providing a device which can inhibit blood from circulating through muscles, which can vary a compressive force imparted to the muscles while the force is accurately grasped, and which allows to exercise with the device attached to the body.

An inflatable cuff for measuring blood pressure is improved so that a baffle plate 6 is provided along the outside of the tube 5 in the cuff 1. The baffle plate 6 regulates inward the expanding direction of the tube 5; therefore, even if the inflatable cuff 1 and the tube 5 are narrowed, the tightening pressure works on the inside.