I got on the treadmill and warmed up but as soon as I accelerated to a run, my knees started protesting: I had not even thought to tape them. Forget it, I decided, and used an elliptical instead. Fake exercise. 30' @ 100% incline and 45% resistance, and I didn't need my 150 bpm dance-mix thingie to tell me the elliptical works me less than the treadmill. On a treadmill, 5.2 mph is about as slow as I can comfortably run, and 150 or 151 bpm is fine for that, but I needed lower resistance on the elliptical to match my pace to the bpm. Solution: mixes with different bpm. Whoever assembles these free podcasts (DJ Steveboy) makes them in a range of bpms.