HRm vs MFP

I have the same problem with my Timex HRM. Many other MFP members say Timex HRMs are inaccurate. I compare the HRM and MFP numbers to the results of an equation I found online and I log a weighted average. I input your stats into the equation and it comes up with 358 calories burned. If your profile is correct, I used 33 as your age. Here's the equation for your reference and it's for females only:

= (0.074 x age in years - 0.05741 x weight in pounds + 0.4472 x average heart rate - 20.4022) x time elapsed / 4.184.

For an example calculation, a 43-year-old female weighing 143 pounds exercised for 45 minutes with an average heart rate during the session of 141 bpm:
(0.074 x 43 - 0.05741 x 143 + 0.4472 x 141 - 20.4022) x 45 / 4.184 = 405 calories during your exercise session.

So I have a Timex HRM with a chest strap. I just ran 3 miles in about 36 minutes. MFP says I burned 375 calories, while my HRM says 600. Who the heck do I believe? I thought HRM with chest strap was the most accurate., but that is a huge difference. My average heart rate was 155. I am 5'2" and 170 lbs.

Thanks in advance for your fabulous advice!

600 is way too much.

I wish!

I am not too sure about the Timex and if they have an issue or not but I have a Polar HRM and I feel the Calorie amount it reads out is correct.

I do think its very hard to put an average on a workout as everyone trains at such different levels. As well as their individual fitness levels make a difference as well.

My step instuctor wears the same HRM as me- obviously very fit - works her butt of for the 60 min class and so do i but I am nowhere near as fit as her and she can not get over 500 cal burn as hard as she tries! whereas I can bur between 600 and 700 calories in my session.

I can also do the same class and duration but not put in as much effort and only burn low 500s.

Since having my HRM I have also found that my calories have not been as high as when I first got it while doing the same excercise I did only a few months ago. Thats because I am so much fitter. I don't peak at the super high HRM as much and I have a much quicker recovery. ie. my HR is not sitting up as high for as long as it used to.

So in my opinion, I think the HRM's are correct. again, I am not too familiar with the Timex.

My experience anyway.

Good luck!

Timex HRM's suck.. Period. If you get one of the cheaper ones that don't allow you to enter gender, then it assumes you are a male and thus gives off the calorie burn of one. Even if it does allow you to enter all info.. they still suck.

Go with MFP for now until you can take the darn thing back. Then get a Polar and save you're self a big headache.

And I had a look at alot of my previous runs and stats from my Polar readings and the 600 does look incredibly high even for when I was unfit!
Like the others say, might have to do some re-calculations. Or get a POLAR!

I weigh 185 and am 5'7" When I run 3 miles in 36 minutes I burn about 450 calories or less. Because you weigh less than me, your burn would probably be a bit less. :-( Sorry

I have a Polar as well and love it! Actually have two just got a new one for xmas!! My trainer told me go with what my monitor says.