HRM~ fat v. muscle (how accurate)

jenluvsushi

Hi all.....I have a question for all the big brains on MFP. How does a HRM determine calorie burn strictly by pulse, age and weight? In my mind a more muscular person should burn more than a not so muscular person even if they weigh the same. In the same aspect, a more muscular person who works out a lot may have a lower heart rate....A very out of shape person whose heart rate elevates to a much higher level may appear on a HRM to be burning more calories simply because of the heart rate...any explainations? Am I totally over-thinking this? lol! Thanks!

kiminita

It also has to do with the very weight they carry. It takes more energy to move a bigger body (especially one out of shape) than it does to move a smaller body.

drog2323

right...so the more fit the person, the less there heart is pumping to move the body.

so if me and lance armstrong were riding a bike up a hill. I'd be SUCKING major wind and he would be doing it with ease.

so I would be burning more cals since my heart was working harder.

....i think that's how it works.

but yah, if someone is heavier, they will prob burn more than someone who is lighter. as said above...

drog2323

It also has to do with the very weight they carry. It takes more energy to move a bigger body (especially one out of shape) than it does to move a smaller body.

yes...she said it much better than i did.

dad106

No your not over thinking it.

Thats why you need to look for an HRM that takes into account not only age and weight, but also gender, height and VO2Max.
Vo2max a number that basically determines how fit you are.. and the more fit you become, the more the number decreases(I think! Don't quote me on that one!).

Cheap HRM's(like TImex,Sportline, etc) Don't take all this data into account, and thats why their calorie counts tend to be off. HRM's like Polar/Sunnto, do take all this data into consideration, and thus can give more accurate calorie estimations.

Azdak

right...so the more fit the person, the less there heart is pumping to move the body.

so if me and lance armstrong were riding a bike up a hill. I'd be SUCKING major wind and he would be doing it with ease.

so I would be burning more cals since my heart was working harder.

....i think that's how it works.

but yah, if someone is heavier, they will prob burn more than someone who is lighter. as said above...

If you weighed the same, you and Lance would be burning approximately the same number of calories. It's just that he can sustain the effort easily and do even more, and you can't.

Heart rate by itself has nothing to do with calorie burn. That 's the mistake that people make when they claim that doing hot yoga, for example, burns huge numbers of calories.

Heart rate is only an indicator of relative intensity--i.e. that "x" heart rate indicates you are working at "y%" of your maximum.

Azdak

Hi all.....I have a question for all the big brains on MFP. How does a HRM determine calorie burn strictly by pulse, age and weight? In my mind a more muscular person should burn more than a not so muscular person even if they weigh the same. In the same aspect, a more muscular person who works out a lot may have a lower heart rate....A very out of shape person whose heart rate elevates to a much higher level may appear on a HRM to be burning more calories simply because of the heart rate...any explainations? Am I totally over-thinking this? lol! Thanks!

Heart rate is only significant when it can be used as an indicator of aerobic intensity (oxygen uptake). During steady-state aerobic exercise, there is a consistent relationship between heart rate and oxygen uptake and both change the same way in response to changes in intensity.

So if you know that your heart rate is "X" and "X" represents 70% of your maximum and you know your maximum oxygen uptake is "Y" then it can be estimated that you are working at 57% of "Y" (don't worry why it's 57% and not 70%-just accept that it is). Once you know the workout intensity, you can convert that into a calorie estimate.

HRMs use the same general principle, although they derive their estimates in different ways. HRMs have to use a number of mathematical factors to increase the accuracy of their predictions--so they use age, gender, height and weight, and some also include activity level or allow you to directly enter VO2 max.

In the real world, only intensity and weight are significant factors. Height, gender, age are not necessary. I know of no literature that has looked to see if there is a difference in oxygen uptake for individuals based on differences in body fat percentages.

Azdak

No your not over thinking it.

Thats why you need to look for an HRM that takes into account not only age and weight, but also gender, height and VO2Max.
Vo2max a number that basically determines how fit you are.. and the more fit you become, the more the number decreases(I think! Don't quote me on that one!).

Cheap HRM's(like TImex,Sportline, etc) Don't take all this data into account, and thats why their calorie counts tend to be off. HRM's like Polar/Sunnto, do take all this data into consideration, and thus can give more accurate calorie estimations.

VO2 max will INCREASE with training. Max heart rate will stay the same or decline slightly.