Treadmill motors are rated by the amount of horsepower they provide. The higher the horsepower (HP) rating, the larger and more powerful the motor. Some treadmills are rated at continuous-duty horsepower (CHP). A 2.0 CHP motor is actually more powerful than a 2.0 HP motor. For details, see below:
Continuous Duty Horsepower: A measurement of the motor's ability to maintain a listed HP over an extended period of time. This test is considered the most accurate indicator of motor output, because it is performed at the voltage used in application by the particular motor.
Horsepower: A calculation of the motor's maximum horsepower. This provides no measure of the motor's HP over an extended period of time. Experts agree that continuous-duty ratings are the more accurate indicator of true performance.