Polar H7 Burned Calories way more than supposed burn

bradnewsom

I'm sure there is one post somewhere lost in the internet void, but I'm asking hear for convenience and in hopes of finding an accepting community unlike reddit and the like.

Right to the question, I use a Polar H7. I don't rely too highly on calories burned from it the same way I don't rely on watches. What I noticed, I burn at least 200 calories more than what I'm suppose to burn based on a ton of generators that generate the supposed burned calories.

For example, Tuesday on my active rest day, I walked 5.35 miles in one hour and 30 minutes. Burning 1023 calories. Based on generators, I only burned 260 for 3mph pace and 544 for 4mph.

What is going on? With the H7 syncing with FitnessPal, wouldn't I be eating back WAY more calories than what I supposedly lost?

I'm so confused about this system. Does the H7 include the calories you burn resting or is that removed from the total? If not, why the hell does the system sync with MFP in this form if it is incorrect and overshooting?

Thanks! I hope I can get a clear and concise answer for this. I'm not eating back the calories burned from exercising and I'm losing about 1pound a week, a healthy amount. So, I know I'm doing something right. I just need to better understand how to utilize my H7 with my workout with making complete guess work out of it, especially when I'm juggling gaining muscle on top of losing weight.

Azdak

The H7 as I understand is just a chest strap sensor transmitting HR signals. It's the fitness app or watch that you are using with the H7 that is actually providing the calorie numbers.

Morgaen73

If by generators you mean apps that calculate calories burned and don't take into account your heart rate then they cant possibly be as accurate as the HRM. My wife has used my H7 alongside her Apple Watch and the HR is spot on. As far as calories burned goes I used mine with the POLAR app and it is way more conservative ito calories burned than either MFP or the gym machine.

50extra

Which app are you using? I use an H7 myself for cardio and no matter what app I use, the absolute maximum I allow myself to eat back is 50% of calories burned. When I stick to that I lose right on schedule.

bradnewsom

I use Polar Beat, so it tracks everything H7 has to offer. It then syncs with Flow which then syncs to FitnessPal. Thanks for your insight 50extra!

50extra

Yeah I use beat as well, it is very similar to the calories burned on both my fitbit blaze and what myfitnesspal has in its preset logs. I firmly believe it is 2x high, which is why I try to do the 50% rule.

MeanderingMammal

bradnewsom wrote: »

For example, Tuesday on my active rest day, I walked 5.35 miles in one hour and 30 minutes. Burning 1023 calories. Based on generators, I only burned 260 for 3mph pace and 544 for 4mph.

HR is not a reliable indicator of calorie expenditure at low levels of exertion, such as walking.

Regardless of walking slowly or at a comfortable place you'll expend 0.3* bodyweight (lbs) per mile.

When you're using a tool, such as HR monitoring, you need to be aware of when you're using it as designed, and when your use of away from design characteristics.

That said, as above, the H7 is only a pickup and transmit. The magic happens in the app it seems the data to.

NorthCascades

Morgaen73 wrote: »

If by generators you mean apps that calculate calories burned and don't take into account your heart rate then they cant possibly be as accurate as the HRM.

You would think so - because your HR gives a big clue to how strenuously you're working, plus more info is usually better than less - but it's not actually the case.

Sometimes HR is a red herring. Suppose you go out for a walk around the neighborhood, and you stop to have a cup of coffee along the way. The caffeine will elevate your heart rate. So would stress, dehydration, and any number of other things. To your heart rate monitor, it will look as if you're suddenly working much harder when any of these things happen, because an HRM isn't a caffeine monitor.

The world's most accurate ways of measuring exercise calories don't use heart rate. They use masks that measure the gases you breathe in and out to see how much oxygen you're using, or they use devices to measure the physical work you're doing. Because when you get down to it, HR is useful to know but it's not the secret at the heart of our metabolism.

bradnewsom

MeanderingMammal wrote: »

When you're using a tool, such as HR monitoring, you need to be aware of when you're using it as designed, and when your use of away from design characteristics.

Ok, well tell me what are the design characteristics? Because there is no reason why my use strays "away from design charactersitics". The design is made for exercise, including walking. I walk and sprint. That is a characteristic of the design. If not, then why would they make the effort to "design" a platform that syncs such an inaccurate design with MyFitnessPal? Its funny because walking with weights can be just as intense as running. Did you think about that? Or are you making a generalization in turn becoming condescending?

sijomial

bradnewsom wrote: »

MeanderingMammal wrote: »

When you're using a tool, such as HR monitoring, you need to be aware of when you're using it as designed, and when your use of away from design characteristics.

Ok, well tell me what are the design characteristics? Because there is no reason why my use strays "away from design charactersitics". The design is made for exercise, including walking. I walk and sprint. That is a characteristic of the design. If not, then why would they make the effort to "design" a platform that syncs such an inaccurate design with MyFitnessPal? Its funny because walking with weights can be just as intense as running. Did you think about that? Or are you making a generalization in turn becoming condescending?

You are mistaken if you think all heartrates correspond to a particular calorie burn. HR is used as a proxy for oxygen uptake during aerobic cardio. That proxy relationship is an average of tests taken in a lab under controlled conditions. With a basic HRM at best you are getting a reasonable average of a representative sample.

Go outside those test conditions and you are in the realms of guesswork.
Steady state cardio (such as running or cycling) can be reasonable.
There's going to be massive differences between people's low intensity HR during walking which will bear little relation to their actual calorie burn (that's a function primarily of mass being moved over distance).

Your sprinting will be another really poor use of a HRM. Remember they are designed as heartbeat counters and not calorie counters, a training aid not a measuring device for energy.

Start using it for strength training (your farmer's walk example) and the estimates will be even worse, typically strength training feels hard and your HR is elevated but the actual calorie burn is low.

NorthCascades

bradnewsom wrote: »

Ok, well tell me what are the design characteristics?

A heart rate monitor is designed to tell you what your heart rate is. It's not designed to tell you what your calorie burn is.

MeanderingMammal

bradnewsom wrote: »

MeanderingMammal wrote: »

When you're using a tool, such as HR monitoring, you need to be aware of when you're using it as designed, and when your use of away from design characteristics.

Ok, well tell me what are the design characteristics? Because there is no reason why my use strays "away from design charactersitics". The design is made for exercise, including walking. I walk and sprint. That is a characteristic of the design. If not, then why would they make the effort to "design" a platform that syncs such an inaccurate design with MyFitnessPal? Its funny because walking with weights can be just as intense as running. Did you think about that? Or are you making a generalization in turn becoming condescending?

An HRM measures your HR, you can then use that to extrapolate calorie expenditure in those circumstances where there is a reasonable corellation between the two.

The greatest correlation is where one is exercising in steady state, in the aerobic range. So if you're walking the corellation is low, HR isn't a good indicator of calorie expenditure. If you're varying your pace significantly, so you've got big deviations, in HR then there is a significant degree of error in the estimations.

Similarly if you're approaching, and exceeding, the anaerobic threshold the relationship breaks down again. Essentially the level of correlation is a classic bathtub curve.

The software that is used to extrapolate calorie expenditure can only deal with known relationships. More sophisticated systems can use a number of methods to account for periods when the relationship between HR and calories is weak, but essentially the assumptions increase a lot.

For the example you're decribing a situation where most of your calorie expenditure is based on body mass and distance. If you're walking wearing, for example, body armour then your HR will increase, but not in a ways that's going to indicate the difference between walking with, and without. The cause of the HR variation isn't your cardiac effort.

AnvilHead

NorthCascades wrote: »

bradnewsom wrote: »

Ok, well tell me what are the design characteristics?

A heart rate monitor is designed to tell you what your heart rate is. It's not designed to tell you what your calorie burn is.

Furthermore, while a HRM measures your heart rate, it doesn't measure anything as far as calorie burn - it extrapolates an estimated figure based upon lab-derived algorithms (which vary between manufacturers), which are derived from steady-state aerobic cardio. So the calorie burns are an estimate in the first place, and the further you deviate from steady-state aerobic cardio, the further the estimation loses accuracy because the exertion isn't relevant to the model the algorithm is based upon.

sweetpea813

My Polar HRM with the chest strap has been reliable for me but then again, I don't eat back all of my exercise calories. I don't wear it for walking, I only wear it for high intensity cardio classes.

NorthCascades

I use my HRM to evaluate the quality of a workout. Like if I need an LSD ride, I tend to get a bit spirited at time, and the question when I get home is did I spend most of my time in Z2? When I run more than a mile or two at a time, I try to keep my HR just below 165 because that's my threshold, and because it's easier to get an accurate value for HR than it is for right this minute pace, at least in a built up city.

Azdak

This is the another big issue with HRM calorie readings which often is not mentioned--cardiovascular drift. Shown is my HR graph from yesterday--45 min on Stairmaster. While I was varying the workloads within a narrow range, average workload remained roughly the same for the entire workout--machine counted 402 calories for the first half of the workout and 409 for the second half. (The actual calorie count is inflated because there is some handrail support, but it is a reasonably accurate measure of total work performed and is independent of heart rate).

As you can see, there is a steady increase in HR response even though average workload is mostly the same. The HRM calorie count paints an even more dramatic difference--277 calories for the first 1/2 of the workout, 356 for the second half.

Overall, the machine counted 811 and the HRM 633, which is pretty typical for me. The high number (esp on the stairmaster) is an overestimate, I know. The HRM number is almost certainly too low. Within the workout, the HRM calorie number for the first half is probably really low, and the second half is probably pretty close.

For me, those numbers are as accurate as I expect and as accurate as I need. I basically divide my workout calorie goals into 3 categories--250-400 (net); 450-650, 700+. That gives me the best balance, both for weight control and training.