Originally Posted by
ericy
For the most part I would agree. But if you have a power meter on your trainer/bicycle, it will be directly measuring the amount of energy you are using to push the pedals. Getting from there to a calorie count is a lot more straightforward than trying to guestimate it based on heart rate or other such things.
I understand there are efficiency differences in power production. Then over on the running side it gets worse, where Garmin and Stryd have wildly different numbers for the same pace/ effort, both backed by a number of research papers but the numbers indicated by the various research disagree with each other. Yet other research disagrees with run power as a concept. Much like L/R balance in cycling power, there's also very little to do with the numbers yet other than plug it into cycling power-based workouts and assume it all translates, which is unlikely.
Cycling power meters are excellent for pacing and measuring capability. The calorie burn numbers derived from them are much less compelling.
Which reminds me, I need to cook up my 5x20@80% workout.