Heart Rate Monitor - is it really accurate?

squashyhelen

I just bought a Polar Ft4. The discrepancy is crazy!

I played some Zumba Kinnect. On MFP, it tells me 14 mins for Dancing, general, is 58 and for Dancing, aerobic is 62. I always thought this was a bit low for how much sweat I generate. Kinnect tells me I expanded 98 calories. My new and shiny HRM ... tells me I expanded 170 for 14 mins of zumba. Even if I subtract the 32 calories expanded white sitting there for 14 minutes, that is still 138 for 14 minutes of activity. 40 more than Kinnect tells me, and a whopping 80 more than MFP's "Dancing, General."

What in the world? Which number is more accurate? What do I log? More importantly, can I eat some more, or not?

AnnetteMY

I have a Polar FT60 and I think it's more accurate than what MFP states because it actually puts in consideration the intensity of each individual workout based on your heart rate and personal profile.

squashyhelen

I want to look like you! That being said -8 hours of puttering around before sleep + sleep came to around 500. If you extract that, wouldn't it mean the Basal Metabolic Rate is 1500? 250 higher than the number calculated by MFP (26 years old, 122 pounds, not that lean right now) - it's in fact 1/6 more. Would you then decrease any number given for an activity by 1/6th? So confused...

jacksonpt

They are all just estimates. For most "non-standard" exercise, HRMs will be a bit more accurate, but even so, it's just an estimate.

squashyhelen

Has anyone else vigorously monitored their intake and exercise and subsequent weight loss in conjunction with the information provided by a HRM? Did you find it to be accurate?

jaz050465

But a HRM won't take into account your non-exercise activity. I've read about people who have done this with a Bodymedia Fit.

Mokey41

I want to look like you! That being said -8 hours of puttering around before sleep + sleep came to around 500. If you extract that, wouldn't it mean the Basal Metabolic Rate is 1500? 250 higher than the number calculated by MFP (26 years old, 122 pounds, not that lean right now) - it's in fact 1/6 more. Would you then decrease any number given for an activity by 1/6th? So confused...

A HRM is only accurate with an elevated HR. You can't wear it all the time to determine BMR or TDEE. The algorithms it uses don't work that way. I find my FT4 to be quite accurate.

weloveourboys

Yes, they are extremely accurate at telling you what your heart rate is, which is what their main function is.

Erienneb

I was tested for heart rate in conjuction with VO2 max which gave me a much more accurate reading of how many calories I burn per minute in certain HR zones. Then I plugged the zones into my HRM (which is a Polar RS300) and it knows that for HR zone one, 134-144 I burn an average of 8calories a minute, and so on....I round down when I log because it's not perfect, but much more accurate than the MFP readings which sometimes are so bogus it's insane. For me anyway.

squashyhelen

Thanks, guys, that was incredibly helpful!