US Patent 7786856 Exercise monitor

A device for measuring the aerobic capacity of a subject, has an input for receiving a measurement of distance travelled in a given time. The time is chosen to be sufficiently large to ensure that the user is working at the maximum of his or her aerobic capacity. A processor determines from the values of distance and time an aerobic capacity, and a measure of exercise level is output to the user based on the calculated aerobic capacity. The calculated aerobic capacity conforms to the relationship expressed as V02max=a+bx+c(x^2) wherein V02max is the maximal oxygen consumption of a user; a, b and c are non-zero constants, and x is a measure of distance per unit time.