Polar HRM calorie burn estimate accuracy - study

I am always amazed at how people will dismiss exercise machine calorie numbers out of hand but will accept HRM calorie numbers as "truth" without any question whatsoever.

Whoever designed human brains had a wicked sense of humor.

Do you think the machine values are perhaps way off because the calibration of actual speed is bad?

I was on a treadmill at gym that was flashing a warning about lubricating the belt or such, so I told the staff.
"we'll reset the warning"

Not we'll fix it, not they need oil from time to time, ect. We'll get rid of the warning.

Made me wonder if they ever did the required re-calc after so many belt miles. I got the manual for it awhile back to use the trainer's features on it (nothing like saving your interval routine under a trainer's code for access later, if I get that machine anyway!) and noticed re-calc is supposed to be part of normal routine on it.

If belt is off, then speed is off, then calc's is off. Because I just don't see why they wouldn't use the standard calc's for MET's when they know the weight, pace, incline, ect and could nail the calories needed for that effort.

Agreed. I think it must be the active selection process. The machine numbers are just there. MFP numbers are just there. But the HRM numbers....research was done on which is best, questions were asked about accuracy, threads were read about user experiences, and up to $100 was spent on the final selection. With all that effort put in, whatever random number the device spits out is not just true, but TRUTH.

Excellent point.

It must be right because I spent the money on it.

For the majority that seem to ask about recommendations though, I'd bet the research part of it didn't happen, merely the recommendation part of. The questions on MFP looking for a HRM never seem to sound like the least bit of research was done first, which means merely going on popular vote, that happened to notice your thread, at that time of day, from ones that you don't know if they have any idea.

I know I've asked several what their avg HR was for a workout, and they are like, that stat is there? I can give you my calorie burn, does that tell you? Huh, I have Polar too, all those stats are there after a workout.

For most, asking other people what HRM actually counts as the *research*.

The thing that amuses me most is how quickly people bail on their original argument for getting the HRM. Poster after poster says "Don't trust MFP, the burns are too high!" and then you read a thread where the OP says "MFP says 300 cal, my HRM says 550" and every single response says "TRUST THE HRM, use the higher number". Wait, so MFP estimates way too high, except for when it's way too low? Literally any number the HRM spits out, high or low, is taken as gospel, even tho there isn't a source to confirm the numbers with.

I really like the idea of checking it with walking on the treadmill. What's funny about the HRM stuff- I remember I got my first HRM in college circa 2003ish, when I was taking running as a fitness elective- it came with the tuition for the class. The purpose of it was to work on zone training, learn about VO2max, etc. It had a calorie setting, but the teacher/coach told us to use it to gauge performance only- as in, the gross number doesn't mean anything. So I've used it for years that way. Then I got to MFP and saw 8 million posts about using HRMs, and I remember one of my first posts was asking if everyone was using zone training, and how they could possibly be using it for DVDs and whatnot- was I ever surprised to find out the HRM had become exclusively a calorie counter! I really don't have a point to this anecdote, except how interesting it is that the purpose of the tool has changed so much.

So true, and the HRM companies have complied by making it a primary focus and leaving out other useful stuff. So the cheaper Polars have no zone alarms, except an upper one. No multiple zones, missing a bunch of other features that the chipset can probably do, but is disabled.

Its the blind faith issue that drives me nuts as well. The fact that these, and other devices, are not accurate is no secret, and has been stated many many times, even on this forum, but people believe what they want to believe. I see people posting over and over that hrm readings inflate calorie burn for strength training, and studies that support that fact, but also see post after post telling others to wear a hrm during strength training to know your calorie burn.

Hrm's are designed to do one thing, tell you your heart rate. The calorie burn function is best described as "for entertainment purposes only". Don't know about others, but I find people using the readings so literally, and making sure they eat those numbers back, to be VERY entertaining sometimes.

Well, the studies have shown they can get closer than probably just to entertain or curiosity aspect.
The Firstbeat algorithm HRM's have shown really good accuracy over course of a day in a study, if within 10% is good anyway of metabolic chamber.

But still again, that all applies on other stats being entered correctly on it, or the assumptions the HRM must be making if it's a stat you can't enter.

And correct usage as you indicate, most are designed with steady-state aerobic, anything outside that, even with correct stats entered, is going to lose accuracy, like weight lifting you mentioned. Or HIIT that is popular.
You look at the studies on the benefits of HIIT for fat burning say, and the energy expended is 1/2 or less what the aerobic endurance group did per hr, and you realize that the logged 900-1000 cal burns doing HIIT are no where near accurate.
Of course, that implies the HIIT is being done correctly too.

Practically, how many HRMs use Firstbeat technology? And how many actually use R-R analysis? (which I think you need in order to get the full benefit of the FB software, although I could be wrong). For example, you have to go all the way up to a Polar RX800 (RS800?) or Suunto T6d to get the full R-R analysis feature and now you are over $400 for the HRM. I asked some of these questions to people at First Beat, but never got a real answer (I got answers, but, even in English they didn't make any sense ;-). And I could never bring myself to drop the $$ on one for myself to try it out.

Excellent point.

Even the Garmin's are up there in price, but not that bad though, wow. I knew Suunto always seemed overpriced to me, and the nicer Polar's, but wow. And I've noticed some of the Suunto's use the Firstbeat training stuff, not calorie burn stuff.

But probably when you are getting that nice of a HRM, that is indeed for training and logging and ease of doing intervals because of correct timers, easier to use zone control, ect. Now at that level, calories is probably a side stat, interesting, but the athlete knows how much they need to eat to keep performing.

I have been very impressed with the Garmin 310XT. I'll do extra laps so a segment has stats on it's own, just for comparison.

I've noticed that the first 5-10 min has higher cal/min during that warmup, compared to cooldown last 5-10 min at a higher HR actually. And any laps at harder effort, even with same or higher HR, start showing less and less cal/min.
I've noticed that at the exact same HR, a hot day has less cal/min, because of heat elevated HR, but effort isn't really that hard.
I've noticed that a low HR cardio activity the day after weight lifting of same muscles, gets higher cal/min than same low HR day after an aerobic day. Harder to use the sore muscles, more effort even though HR doesn't reflect that fact.
On HIIT activity, despite the high HR, I show the smaller cal/min as expected, and depending on how fast I let the HR drop to recovery.

Found it very cool.

In fact you can do a Leaf test to put your stats on there as to how many calories burned for HR ranges, but I think that would actually be less accurate.
I do wish though I could put in my own tested VO2max rather than it using the formula and data logging to calculate what it must be. It's probably semi-close, but since it's based on BMI rather than bodyfat%, I know it's off.
I'm planning on making a spreadsheet with what the Leaf test would do anyway, test some sample data and see where it's at.