jammin + gym = jymmin
Scientists hooked up exercise machines to computers that produced music according to the movement of the people using the machines. Those who created music as they worked out reported feeling less tired and believed they had exerted less energy than did those that listened to prerecorded music.
And, active music-making during physical exertion improved mood "to a far greater extent than passive music listening."
The future of exercise machines? Bring your axe to the gym and plug it into the treadmill.