Slow walking burns more calories. (Horray for the rest of us

songbyrdsweet

Both...each person has a different metabolic rate and their organs will use different amounts of calories. A larger heart will require more calories, so a small female's heart would use less than yours does. Energy needs of all tissues increase with increased workload, so the cals per beat would increase if you needed a more powerful beat. The average wattage of a heart is 2.3, but the sources I checked listed anything from 1.3 to 5. That value of 4.5^-4 calories would only apply to an individual with a RHR of 70 bpm and a perfectly average-sized heart during rest.

Understood your above, but I am wondering if an individual has a linear or exponential scale...

Say me - 192lbs, 6'2", ~18% Fat, MBI ~24.8 BMI -

At 70hbpm = X calories being used
At 100bpm = X + Y calories being used
At 150bpm = X + Y +Z calories being used

If some college people did a study and attempted to figure out your bmp vs calories and found that it was linear, it wouldnt be difficult to figure out at all. Then you could told your heart beats for the day, * by your unique constant and get how many calories your burnt.

Ahhh I see what you're saying! That would be neat, although just HR wouldn't give you a totally accurate value since it's not linearly correlated to total energy output. It wouldn't really be exponentially linked either. The rest of your organs and muscles have different caloric demands. It's more accurate to measure oxygen consumption, which is still independent of the HR. No matter how fast your heart can beat, when you're sprinting, your lungs jut can't oxygenate it fast enough, so while the HR would be high, the oxygen consumption would be low, and total caloric output would be fairly low (mostly due to the short length of time rather than power output, which would be high). Plus you'd still have to subtract your hourly RMR calories to determine how many net cals you actually burnt during exercise.