Relation between calories burnt and heart rate

Wiltord1982

Hi everyone,

I have a question about the relation between the amount of calories burnt and the heart rate. So, is there a relation?

For example, does running at 150 bpm burns as many calories at biking or swimming at 150 bpm? Is that how it works?

That question popped in my head tonight as I was doing cardio on machines at the gym and wanted to try them all... I wondered if they were all made equal, that's it

Thanks!

DavPul

The relationship is tenuous at best. Skydiving can have my heart beating at 150 per minute too, but with zero calories burned

Wiltord1982

That makes sense. I guess running remains the best calorie-burning exercise

DanIsACyclingFool

And yet everyone (including me) preaches using an HRM to predict calorie burn as a superior method to things like MFPs online database.

Skydiving, muggings, and your first experience as a stripper aside, an HRM that makes the ASSUMPTION that you are exercising is probably the best tool for predicting your caloric burn. The only scientific way I know to measure your actual energy expense is to use either direct calorimetry (measure heat given off the body) or indirect calorimetry (monitor your respiration and measure the exchange of oxygen and CO2). Both are obviously impractical for exercising at your local gym.

An HRM measures (obviously) your heart rate. The more exertion the body experiences, the higher your heart rate, and the higher the caloric burn. Thus, average heart rate is proportional to average caloric burn. It's the best tool we have, at least until Starfleet Medical releases a tricorder onto the market.

I think any exercise that puts you on a particular heart rate will be taxing the body approximately the same as any other, regardless of the muscles used to do the taxing.

Azdak

And yet everyone (including me) preaches using an HRM to predict calorie burn as a superior method to things like MFPs online database.

Skydiving, muggings, and your first experience as a stripper aside, an HRM that makes the ASSUMPTION that you are exercising is probably the best tool for predicting your caloric burn. The only scientific way I know to measure your actual energy expense is to use either direct calorimetry (measure heat given off the body) or indirect calorimetry (monitor your respiration and measure the exchange of oxygen and CO2). Both are obviously impractical for exercising at your local gym.

An HRM measures (obviously) your heart rate. The more exertion the body experiences, the higher your heart rate, and the higher the caloric burn. Thus, average heart rate is proportional to average caloric burn. It's the best tool we have, at least until Starfleet Medical releases a tricorder onto the market.

I think any exercise that puts you on a particular heart rate will be taxing the body approximately the same as any other, regardless of the muscles used to do the taxing.

Not everyone.

The fundamental problem with HRMs is that they are only possibly accurate under a narrow set of exercise conditions. The only time there is a consistent relationship between HR and calories burned (VO2) is during aerobic exercise at steady state.

Heart rate may increase under other conditions, but the heart rate increase in those cases is driven by different physiological responses, and thus the heart rate-oxygen uptake-calorie burn relationship does not exist.

And even under aerobic steady-state conditions, there is a difference in heart rate response comparing activities like running, cycling, and swimming for example.

So, over time, one can use heart rate response for the same modality as a gauge of training intensity and perhaps even calories, but it becomes tenuous to use it to compare effort for different activities.

Take into account the differences in quality between different HRM models and the differences in accuracy in how people set up their HRMs (including the wide range of HRmax values in the normal population) and the usefulness/accuracy of using an HRM to predict exercise calories ranges from "roughly in the ballpark" to "pick a number out of a hat".

DavPul

And yet everyone (including me) preaches using an HRM to predict calorie burn as a superior method to things like MFPs online database.

Skydiving, muggings, and your first experience as a stripper aside, an HRM that makes the ASSUMPTION that you are exercising is probably the best tool for predicting your caloric burn. The only scientific way I know to measure your actual energy expense is to use either direct calorimetry (measure heat given off the body) or indirect calorimetry (monitor your respiration and measure the exchange of oxygen and CO2). Both are obviously impractical for exercising at your local gym.

An HRM measures (obviously) your heart rate. The more exertion the body experiences, the higher your heart rate, and the higher the caloric burn. Thus, average heart rate is proportional to average caloric burn. It's the best tool we have, at least until Starfleet Medical releases a tricorder onto the market.

I think any exercise that puts you on a particular heart rate will be taxing the body approximately the same as any other, regardless of the muscles used to do the taxing.

This is well written, logical, and thoughtful......yet fundamentally incorrect. That's my biggest issue with the way hrms are presented in this site day after day. It seems to make sense but the science just isn't there.

As a measure of intensity, absolutely. As a measure of calories burned, no. But 90% of the people on this site are relying on them for calories.

There's a reason they are called HEART rate monitors, not CALORIES BURN monitors. They would get sued out of business if they called them the latter.

meerkat70

azdak i've always found your argument compelling on this.

but what would you suggest as a reasonable best guess method, since we all have to make some kind if estimate to get our sums to balance.

SJCon

Az and Dav are correct but so are the other posts on this thread. As mentioned the real way to come the closest in measuring burn is not practical outside of a Lab, Also keep in mind that the tables are also an estimate and do not reflect a "True" measure of burn, they are not lab condition measures. So use the best tool you have available. For Dav that will never be a HRM, he is knowledgeable, consistent and makes a good point which I take to be, know the strengths and weakness of whatever tool you are using. Is a WAG better than tables or a HRM or even a Fitbit? Never but to answer the question asked, cycling mostly uses lower body where running uses more of the whole body., both are aerobic but a HRM would probably better reflect the burn for running rather than cycling. It all goes to the VO2, which is why the HRM is way off on burn for weight lifting or resistance equipment and people often us the circuit training numbers. Those assume you are doing aerobic work like steps or jacks between sets ergo more whole body exertion.

Just my two Coppers and I also don't think running is the best way to burn calories but that is another thread.

DanIsACyclingFool

So the question remains...what to use to help us "balance the books"? After all, this entire site/app is devoted to exactly this kind of accounting.

9 months or so ago I was frustrated with "winging it", and the inconsistent success it brought. I did my part with weighing food, but as for calories going out, was pretty much relying on mfp's estimates. It wasn't working too well, and I figured the missing part of the puzzle was a device that told me what I was burning on a dynamic basis as my body changed. I was basically willing to pay anything for a device that would help me stay in a safe deficit. (Back then I also believed all the scare mongering about starvation mode, too, so I felt my deficit window had to be fairly narrow).

WAG is out.
Real calorimetry is impractical.
That leaves us tables, body media devices, hrms, and ???

The issue I have with tables is that the database has no idea how fit I am. It may know my lean mass but not how conditioned I am. As an insanity veteran, my cardio capacity is higher than it would have been had I chosen some other less intense regimen, and that fact seemed important.

IIRC Body media devices often use skin temp as one of their metrics, which at least seems like an attempt at measuring heat output.Still, I found myself skeptical that they'd give the best data.

Popular opinion seemed to be that hrms were the way to go. Of course, I'm also acutely aware now how much misinformation and bro science is around here, but back then, I just went with the most popular answer.

As for hrms as I've gotten fitter my average heart rate has gone way down, indicating I am doing the same activity at a lower intensity. Consequently my caloric burns will be lower, and I'll have to add intensity back in the form of resistance, speed, etc to get the burns back up. I'm fairly confident that this is somewhat realistic. Does it give me an exact number? Yeah....is it scientifically accurate and admissible in court as an absolute value? No way...no more than the number on the side of a box of poptarts is a scientific measure of how many calories I ate. But you shouldn't be going down to the exact calorie anyways. A deficit or surplus should be designed to give some wiggle room.

So I guess my position is that an hrm is the best guess I can make in terms of my personal energy expenditure during cardio (mostly intervals of various lengths, and lot's of cycling). The number I get isn't perfect...but is there something that can give me a better one? Az, Dav, Sj, how would you rank the various methods discussed?

thanks!

Mr_Knight

I have a question about the relation between the amount of calories burnt and the heart rate. So, is there a relation?

There is a relationship, but it is dependent on knowing your physical fitness level, and is also a function of body mechanics (more so in some sports (swimming) than other sports (walking)).

I know there is a tendency on MFP to use HRMs as the gold standard for calorie burn estimates, but it's really not appropriate, for most people, most of the time. The biggest benefit, IMO, is that it gets people away from the "vigorous/moderate" self-selection MFP makes users do in the MFP database, which is just a recipe for disaster for most people for what should be obvious reasons.

In the end, anyone who wants a serious measure of accuracy will need a consistent exercise routine and a consistent measuring tool, so they can work out the delta/fudge factor and adjust for their own circumstance. This obviously requires meticulous logging of both food and exercise.

I, personally, use very basic calculators for burn estimation that use body weight and distance as the prime determinants in burn estimation. Cycling, running and swimming are my primary cardio exercises, and there are unique calculators for each.

DavPul

So the question remains...what to use to help us "balance the books"? After all, this entire site/app is devoted to exactly this kind of accounting.

the problem lies in this mythical search for the perfect calorie accounting method. you don't need exact figures. you just need to be close. and for close, a person can rely on common sense just as easily as a device. give yourself between 8-12 cals per minute of vigorous exercise and you'll be ballpark enough to lose weight consistently. you can always adjust up or down from there depending on the results.

it's always struck me as odd that people look for some hyperaccurate method of calorie counting when everything else involved in the equation is an estimate. you don't know your real tdee. even if you slept in a lab for a week to figure it out, it would still vary from day to day based on activity level and outside influences. unless you measure every single bite that you place in your mouth your cals are an approximation as well.

so the formula is: tdee is somewhere between 2500-2900, cals eaten are somewhere between 2100-2500 but i must know that my cals burnt today are EXACTLY 452.22? Pretty sure you'll lose consistently if you plugged in 300, 400, or 500. hell, 600

DanIsACyclingFool

Well, I definitely didn't need to know 452.22. What I needed was a way to guarantee with high reliability that x>y. For me I wasn't sure that was happening, or if something else was going on.

And as a newbie, how does one sort out 8-12 cals per minute of vigorous exercise from all the other "facts" and "figures" that litter the internet? We have to weigh how often we hear a particular piece of info and factor that in accordingly. And btw, are you saying I burn 8-12 cal? Or a 130lb woman? Or a 200lb bodybuilder? My logic was that there needs to be some accounting for lean mass and muscular fitness. A one-size-its-all formula seems...WAGish, TBH.

Technology is a useful tool to make life easier, more reliable, consistent, etc. Some people can just decide they're going to lose a few pounds and by making a few guesstimates it just comes off. Others struggle. I don't want guesswork. As an engineering-type, I want numbers.I can't just wing it and hope because it doesn't work for me. I need a formula and some measured data that predicts a certain result, then I track the result and try to correlate it to what I expect. Throw in all the noise about having too big a deficit and I felt that I needed something to make measurements. The best guess seemed to be an HRM.

Anyways, that's why I wanted an device. How accurate is that device is another matter. Like we both said, a few hundred cals either way shouldn't make or break you.

SJCon

In the end, anyone who wants a serious measure of accuracy will need a consistent exercise routine and a consistent measuring tool, so they can work out the delta/fudge factor and adjust for their own circumstance. This obviously requires meticulous logging of both food and exercise.

I think this represents the distillation..............consistent routine and consistent measure. I think that is what all are saying here, we just have different ways of doing it that make each of us feel comfortable. I struggled for a long time and staying in budget seemed to always leave me starving. I was an Industrial Engineer so like DB I by nature look to "Quantify" things and my solution was a BodyMedia link. It indicated my burn appeared to be higher than the norm and set my budget higher, gave me sleeping calories burned that changed with fitness levels (BMR) and let me establish a more personal TDEE. Now I know this is not more accurate than some methods but it was intuitive to me and allowed me to see things graphically. Most importantly it allowed me to set a goal based on a consistent measure and it working very well FOR ME. It is a pain to always wear in the same place but now I can take it off and have a budget I know I can lose with. I am sure things will change and tweeks will need to be made but for me that is a consistent measure that I wear when I need to.
Bottom line ... I agree with everyone's statements on this thread, just proves there are many ways to reach the same goal. BTW I use my HRM as well but mostly to track training load or if I am not wearing my BMF for a break.