I am talking specifically about a paper called Prediction of energy expenditure from heart rate monitoring during submaximal exercise.
It states that within the narrow range of 90-150 bpm, there is a linear correlation between heart rate and calories burned as follows:
EE = -59.3954 + gender x (-36.3781 + 0.271 x age + 0.394 x weight + 0.404 V[O.sub.2max] + 0.634x heart rate) + (1 - gender) x (0.274 x age + 0.103x weight + 0.380x V[O.sub.2max] + 0.450 x heart rate)
However, I have my doubts about this. In particular, how come this formula doesn't factor in the metabolic equivalent of task (MET)? Surely the exercise intensity plays an important role in how calories are burned, or is that just purely reflected through heart rate and V02max?
What I find strange is that it takes very little workout intensity to get my heart rate very high. Just today I ran on the treadmill at a mere 4.7 mph (7.5 kph) for an hour at a sustained heart rate between 145 and 155. Going by the HR formula, I burned around 1033 kcal, whereas running at this speed yields an MET of about 8.3, which yields 772 kcal (my MET is 93). That's not even close.
As another example, a game of basketball has me easily averaging a 160-170 HR (even with all the whistles, timeouts, stop & go, etc) and my HR will sustain 20-30 BPM above normal for at least another 30 mins or so after the game.
I don't think I'm necessarily out of shape. I managed to achieve a VO2max above 50 a week ago via the cooper test. I'm a big guy at 6"6, 245 lbs, roughly 20% body fat. Is it strange that my HR increases so fast from running? Does it make me an outlier with regards to this formula? Should I rely on MET values more than this HR formula for estimating caloric burn during exercise?