A treadmill including a frame, a power supply, and a motor coupled to the frame and to the power supply. An outer circumferential surface of the solenoid valve is covered with a cover, so that a space defined between the cover and the outer circumferential surface is made to communicate with the gas discharge path to thereby form a gas flow path. When an output difference, which is computed based on the first voltage and the second voltage, is equal to or smaller than a second threshold value, an abnormality of the sensed rotational angle of the pedal is determined. Once the tether and stringer are deployed, each of the integrated tools, including the line cutter, the disgorger, and the measuring tape, are also thereby fully available for convenient and immediate use\u2014without any risk of being dropped and lost.