Provided is an exercise device for performing exercises suitable to strengthen thigh and hip muscles such as a leg press machine, a total hip, a stationary bicycle, or a moving bicycle, and more particularly provides an exercise device for strengthening thigh and hip muscles while protecting the knees and ankle joints by enabling a user to locate a lower end of an arm on the user's thighs in a sitting, prone or supine position and move the user's legs in order to minimize a load or stress added to the knee and ankle joints.