Abstract: Embodiments disclosed herein relate to exercise machines. In some embodiments, the device may include a resistance adjuster configured to adjust the difficulty of an exercise performed on the exercise machine. Particularly, the exercise machine may include a knob configured to modify the resistance in even steps. The exercise machine also may include functional components, such as pulleys, for transmitting a drive force from a user to a resistive body. The functional components may be operatively connected via one or more belts. In some embodiments, the exercise machine may include one or more belt tensioners to regulate the tension of the one or more belts.