HRM Question

katydid25

I recently bought a Polar FT4 and love it. However, I was kind of surprised by the amount of calories it says I burned. After a 1 hour workout on the treadmill, the machine and MFP are fairly close but my HRM is about 120 higher. So I checked the Polar website and some past threads and people have said that the HRM also measures my BMR calories but MFP and the treadmills don't. So that, along with the fact I'm sure the HRM is more accurate, would explain the difference in the numbers.

So my question is: When I log the exercise, should I just log the number on my HRM or subtract the amount of calories I'd burn laying in bed for the same duration then log that?

Sorry if this question is nit-picky. Of course I'd rather log the higher number but I don't want to over estimate my calories burned too much.

katydid25

Bump

ALH1981

i found initially my HRM (polar FT4 was sensitive also... but only for running - try some other excursuses -i think you will find that running is just a good heart-rate increasing excersise!!!

funnily enough now my HRM barely measures anything!

mmarin81

I would just go with what the HRM said. I have a sportline and noticed with some workouts it loses the HRT at times so I figure it already has a lil bit of a loss incorporated.

mommyhof3

I have a Polar FT4 and I log and eat what my HRM says I burned. It has worked great for me doing it this way

lisakammwang

I have a polar too. I log the amount burned and do not subract the BMR. Out of curiosity...what is the BMR for that amount of time? My idea is that for that amount of time I probably wouldn't be lying in bed, therefore the difference is probably minimal.

mrtrik

It's a tricky question. Your HR monitor is only taking HR into the equation (and hopefully age/weight/gender). The treadmill is also taking into consideration speed, distance, incline.

That all said you'd think the treadmill could be more accurate. Probably not.

High HR doesn't mean you are burning more calories....

Figuring out a general calories per mile is most accurate. Because almost regardless of speed (and HR) your body burns about the same amount of calories per mile. It just burns it faster. For example, for me it's about 125c per mile. So if I run 10mph or 6mph... it's still about the same. Just one takes longer than the other, and has a much lower HR.

daves160

I dont know if the treadmill has inputs like max HR resting HR, age, weight, etc. Those inputs will give you a better result. I know if I use my garmin 305 edge on my bike, I will burn almost twice the cals as the same amount of time if I use it running. Not really sure why. HR is basically similar, The only difference is cadence and distance(of course).

mrtrik

I dont know if the treadmill has inputs like max HR resting HR, age, weight, etc. Those inputs will give you a better result. I know if I use my garmin 305 edge on my bike, I will burn almost twice the cals as the same amount of time if I use it running. Not really sure why. HR is basically similar, The only difference is cadence and distance(of course).

Also tricky. While the 305 is better (since it takes into consideration distance, speed,elevation).... It's touch for the bike since it DOESN'T know when you are coasting.

High HR could mean high intensity (headwind?) or being out of shape. It doesn't mean you are burning calories faster...

The 2x calories seems wrong though. Generally... You burn about the same running vs biking in a given time. 1hr of moderate effort biking, should burn about the same as 1 hr of moderate running...

daves160

What is "moderate" biking????

I usually ride all out. Lots of climbing average HR is around 160.
running is slower and less effort, but HR is still up there(I dont run much as it is painful due to past injuries), so I likely put forth more effort than I think.

katydid25

Thanks for responses! I was worried I wouldn't get any!

Out of curiosity...what is the BMR for that amount of time? My idea is that for that amount of time I probably wouldn't be lying in bed, therefore the difference is probably minimal.

Its typically about 70-90 calories per hour. It isn't as big of an issue if I'm buring 600 or more but I see a lot of "leisurely walks" that burn about 200 in an hour. That 70-90 calorie difference can add up over a week if you count that as exercise everyday.

Figuring out a general calories per mile is most accurate. Because almost regardless of speed (and HR) your body burns about the same amount of calories per mile. It just burns it faster.

This is a good point! How can I figure out how many calories I burn per hour?

dad106

HRM's when set up correctly(age, weight, height and gender) and used during steady state cardio(IE walking, running, etc) are going to be 80% accurate. If you add in Vo2max or tweak max heart rate, I believe it goes up to 90% or something around there.


If you are really that worried and want to figure out how much you burn an hour, take BMR, divide by 24.. that will tell you what you burn an hour. Some people wear their HRM's at rest to figure out, but since HRM's are not made to be worn at rest, I do not suggest that option.

Bottom line, don't subtract anything out. Everything that you do when counting calories is an estimation.. so an extra 60 here or if you are under 60 one day, will equal out in the end. It's the over all picture that you really should be looking at, instead of individual exercise sessions.