THIS is why HRMs have limited use for tracking calories

MinimalistShoeAddict

Sorry if this is a dumb question but does this mean that the HRMs are best suited for steady cardio activities? Would they be relatively accurate for it?

Yes, those are the only conditions under which they should be considered reasonably accurate.

Now, that also assumes that they are: A) a quality model from a company that does their own research to develop their algorithms (e.g. Polar) and set up properly. To be most accurate, and HRM must be programmed with your actual HRmax and your actual VO2max. Those numbers are not always easily obtainable and some lower-level models (even Polars) do not allow you to manually input these variables. In that case, I don't know how you can make them more accurate.

For example, an HRM will set a default HRmax of 220-age (or close to that). We know that in the normal population, HRmax can vary 20-30 beats from that "220-age" number. If your HRM has a default HRmax of 180, for example, but your actual HRmax is 210, the HRM will substantially overestimate your calories burned--it thinks you are working much harder than you are.

Great point! Everyone should check their HRM to verify the accuracy of these settings.

phjorg1

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

to retain lean mass while eating in calorie deficit... and to improve posture, promote bone density, get stronger, improve athletic performance, maximize fat loss, etc etc. You can go on forever with all the benefits resistance training has. and if you're strong, then lifting will have a very large calorie burn too. Big lifters eat like horses to fuel their body.

You seem to be misunderstanding what the OP is saying. For lifting the HRM has basically zero bearing on calories. But that does NOT mean you're burning a low amount of calories. Just that a HRM is not able to track it. The rule is, the more you lift, the more you burn.

MinimalistShoeAddict

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

Not at all a waste. use your HRM when running. It's a useful piece of gear.

Weight training is important when trying to lose weight. If for no other reason than to maintain your muscle mass.It's extra work for sure, but hardly worthless.

I second this! It is important to realize that there are real benefits to lifting weights besides just burning calories.

AntWrig

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

to retain lean mass while eating in calorie deficit... and to improve posture, promote bone density, get stronger, improve athletic performance, maximize fat loss, etc etc. You can go on forever with all the benefits resistance training has. and if you're strong, then lifting will have a very large calorie burn too. Big lifters eat like horses to fuel their body.

You seem to be misunderstanding what the OP is saying. For lifting the HRM has basically zero bearing on calories. But that does NOT mean you're burning a low amount of calories. Just that a HRM is not able to track it. The rule is, the more you lift, the more you burn.

Great response.

pinkraynedropjacki

Personally I dont care. I've always had my HRM & always taken what it says & entered it here.... guess something must be right cause I've not put anything on & been able to get rid of the weight easy. I refuse to workout without it on. I don't care what the 'data' or 'science' says about it..... it works for me... and works for a whole heap of others. Can't beat that proof.

pinkraynedropjacki

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

Not at all a waste. use your HRM when running. It's a useful piece of gear.

Weight training is important when trying to lose weight. If for no other reason than to maintain your muscle mass.It's extra work for sure, but hardly worthless.

I second this! It is important to realize that there are real benefits to lifting weights besides just burning calories.

Unless you are unable to do anything involving lifting. If I start lifting then I can say goodbye to basic things like walking.

CyberEd312

Bump to read later

lwoodroff

thank you, this is very interesting and the first time I've seen something which correlates the proportions of different types of exercise. I still wear my HRM when lifting, but only to look at heart rate recovery between sets.

EvgeniZyntx

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

Not at all a waste. use your HRM when running. It's a useful piece of gear.

Weight training is important when trying to lose weight. If for no other reason than to maintain your muscle mass.It's extra work for sure, but hardly worthless.

I second this! It is important to realize that there are real benefits to lifting weights besides just burning calories.

Unless you are unable to do anything involving lifting. If I start lifting then I can say goodbye to basic things like walking.

Wut?

And wut?

There are real benefits to exercise other than burning calories. And hrm are useful in measuring HR first (and calories by guesstimating via ze'formulas) HR change is an excellent fitness indicator and training fatigue indicator for overtraining.

I have half a dozen HRMs and for most training I don't use them because frankly I (personally, me) don't need them for the guesstimate on calories. But they can be a great motivational tool. They aren't so much wrong as just a good indicator of activity. And allow comparison over time for the same person in a given specific activity.

Oh, and even in steady state cardio they can be precise but off the target of actual calories based on a variety of measurement variables. Even when you know your VOmax.


Edit - and thanks for the graph - looks like good readings.

CoderGal

Love the OP! Thanks for posting. I'm so glad you wrote this because so many people should see it. Don't get me wrong HRMs are useful and I have one, but it's more useful to know when it is useful.

I'm really disappointed there's people who are taking this to say because of heart rate monitors, they shouldn't have an active lifestyle. That's just depressing and doesn't make any sense at all if they prefer being leaner.

CyberEd312

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

to retain lean mass while eating in calorie deficit... and to improve posture, promote bone density, get stronger, improve athletic performance, maximize fat loss, etc etc. You can go on forever with all the benefits resistance training has. and if you're strong, then lifting will have a very large calorie burn too. Big lifters eat like horses to fuel their body.

You seem to be misunderstanding what the OP is saying. For lifting the HRM has basically zero bearing on calories. But that does NOT mean you're burning a low amount of calories. Just that a HRM is not able to track it. The rule is, the more you lift, the more you burn.

I am almost sure I know the answer to this but still want to front the question mainly out of curiosity, "You say Big Lifters eat like horses to fuel their body" so does this mean if these so called Big Lifters did wear a hrm would it be grossly under estimating there calorie burn or would it be over in its estimate??? If one was to use the MFP approach to weight loss instead of a more TDEE approach, how could they be accurate (or more accurate) in there logging and hitting there caloric intake when they have to eat back some or all of their calories burned when they maintain a lifting regimen of say 3 to 4 days a week of lifting....

CoderGal

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

...What part part were you understanding?

__Di__

The entire concept of using heart rate as means of estimating exercise calories is based on the relationship between heart rate (HR) and oxygen uptake (VO2) during steady-state aerobic exercise.

During steady-state aerobic exercise, there is a relatively consistent relationship between HR and VO2. Working at "X%" of HRmax usually means that one is working at "Y%" of VO2 max. If you know your VO2max and your true HRmax, then you can use that relationship to estimate VO2 during exercise--which means that you can also estimate calories, since calories burned is based on VO2 times body weight.

Once you leave the realm of steady-state aerobic exercise, however, accuracy of HRMs deteriorates rapidly. To understand why, you need to look at this chart:



The chart shows the percentage of VO2max that occurs when heart rate is at 85% of max HR reserve during various activities.

As you can see, it's quite a spread. The red bar is the heart rate--here, set at 85% max HR reserve. The blue bar is steady-state cardio. As you can see, steady-state cardio is the closest match.

While a heart rate of 85% of max corresponds to 75%-80% VO2 max during steady-state cardio, by the time you get to lifting heavy weights, that same heart rate of 85% of max corresponds to only 21% of VO2max.

The HRM doesn't know the difference--it is programmed to display a calorie number based on whatever heart rate it senses. It cannot detect the type of activity. This is why HRM calorie numbers for many non-steady-state-aerobic activities are useless.

The same situation is also true during thermal stress. Heart rate is elevated, while VO2 is not. That's why the inflated calorie claims for activities such as hot yoga are such nonsense.

For some reason, even though this is exercise physiology 101, many so-called "fitness experts" do not understand this. Now that you do, this is one way to evaluate the credibility of a trainer or fitness author. If they say something like "lifting weights can be cardio if you move quickly between exercises to keep your heart rate up", you know you are listening to someone with a serious deficit in their knowledge base--and you'll have to wonder what else they don't know.

How would a person find out their VO2max?

Azdak

Thank you for posting this, it's very useful. One question regarding the chart though: if I read it correctly, I'd assume I could get a better estimate for my calories burnt during e.g. weight lifting by using a factor of 20-25% on my HRM's reading. Is that correct or does it vary so much that it's practically useless?

The strength workout number is just a sample of some data I have pulled from other studies. It is generally representative of the VO2 for that activity, but actual VO2 can vary quite a bit due to differences in individual programs. That variability is why there is no way for a chart or table to give a general calories burned number for resistance training. So, no, that number is not a consistent number you could use in all instances.

mamosh81

interesting post but why do people tend to make all this more complicated then it is? Eat healthy food in moderation and move more is the key for me

unicornpoop

Great, now I am confused and scared to use my HRM for Zumba, Running, Circuit Training and HIIT. Has it all been a LIE?

mamosh81

Great, now I am confused and scared to use my HRM for Zumba, Running, Circuit Training and HIIT. Has it all been a LIE?

you lost 36 lbs so you doing something right id keep it up

Azdak

so from what I am understanding, why should I even bother to do weight lifting when I am trying to lose weight? I cant track the calories so unless I eat half of what I usually do on a lift day, I will come out above on my calories and the whole thing is wasted. So in other words, my hundred dollar purchase was a waste. Great.

I think you just burned 100 calories jumping to those conclusions........:laugh:

I didn't design human physiology--I'm just the messenger. And it must be repeated: no one is saying the strength training does not burn calories, no one is saying that strength training plays an important role in weight loss, there is no hint of a recommendation that people avoid strength training.

The ONLY point of this is to demonstrate that HRMs (and basically all other ways we have of estimating calories burned) CANNOT give a reliable calorie estimate for strength training.

As far as your "hundred dollar purchase" goes, it may or may not have been a waste. HRMs can be useful tools to monitor intensity, keep you motivated, improve the quality of your training, etc. I've been using heart rate monitoring for my training since before HRMs were invented and have used one continuously for 20 years.

But if you ran out and bought an HRM based on the ubiquitous comments on MFP and elsewhere that HRMs are "the ONLY way to accurately measure calories", then, yeah, you might have wasted your money.

Azdak

Great, now I am confused and scared to use my HRM for Zumba, Running, Circuit Training and HIIT. Has it all been a LIE?

It's OK--come in off the ledge.

Any method one uses for estimating calories burned during exercise is just that--an estimate. So nothing has changed, just because the curtain has been pulled aside.

To say an HRM might overestimate your calorie numbers by 20%-25% is far from saying "it's a LIE". You may have overshot the runway a little.

Remember, TDEE consists of: BMR, execise calories and casual activity calories. So, it's all an estimate. Often people underestimate their activity calories, so that even if they are off on their exercise calories, they still lose weight.

However, if you are constantly overestimating exercise calories and using a strict "eat my exercise calories back" method, eventually you would run into issues and see weight loss stall because you were in an energy balance. So, isn't it better to know that now and make adjustments? Or at least be aware, so that if you do stall, you know where to look?

unicornpoop

I was being a bit dramatic, yes. But thanks. I might start cutting off 25% of what my HRM says now.