Its bewildering all the consumer products that go on to track things like watts, etc. I played competitive sports in school and we never bothered with anything like that even if it was available. You run until you are exhausted then you run some more. Same thing with a bike ride if you are trying to put work in imo. Want to train for hills? forget the Peloton, just go and ride up some hills until your legs are cooked, and next week you will be able to ride longer.