I just finished the latest TrainerRoad podcast (ep 459) and at the end of the episode, the last topic they discussed was using a metric of Calories burned per minute - and I searched “calories” and didn’t see that option.
The concept was that in order to improve performance, the goal is to improve your ability to utilize more calories per minute regardless of whether they come from fat or carbs. Since Intervals already has a calories burned metric, I assume it would be easy to add in a calories/min metric as well?
I don’t know the exact details by heart but calorie expenditure during exercise is calculated from Work in KJ. If I remember correctly the work in kJ is the same as the calories in kcal burned. Pure scientific conversion will show show a number that’s 4 times lower but given the fact that the human body is only about 25% efficient, it comes out like that. 1KJ of work is 1Kcal burned.
So all things considered, you could add the Work chart to give you what you’re after.
I assume that is how the Calories burned is calculated given a ride with Power data within Intervals (and other platforms), but intervals doesn’t have the ability to look at this in terms of a burn rate per unit time - does it?
Using the search term “work” Intervals “only” allows you to plot total work over a full activity rather than a minute by minute average burn rate, which is what the research discussed on TrainerRoad was doing.
Calculated Calories burned is always only the assumption that your efficiency is about 25%.
So the assumption is that calories burned is equal to your work done (kJ), as mentioned above.
Calories per time would be kJ per second. The work (J) you have done is power times time (Ws). If you solve the equation you get kJ/s = Ws/s = W.
So Work per time is power.
They actually said to improve performance you have to improve power.
The kcal metric (on a Garmin) is based on a number of permutations based on the technology you have available.
Your estimated Resting Metabolic Rate (RMR), using age, height, weight and gender can estimate calories. Active calories is from an activity, which can use heart rate, breathing, and if power is available, then it can use power too. One doesn’t always need a power meter to get a kcal value.