A treadmill includes a belt, a display, a first sensor having first transmission circuitry for transmitting a first radar beam over the belt and first reception circuitry for detecting a first reflected signal that is a reflection of the first radar beam from a user on the belt, a processor connected to the first sensor, the belt and the display, and a non-transitory computer-readable storage medium storing a program to be executed by the processor. The program includes instructions for determining, according to the first reflected signal, first data associated with a vital sign of the user and displaying, according to the first data, the vital sign on the display.