Calories Not Accurate on HRM?

ohohraptor

I bought a HRM in hopes I could start tracking my calories more accurately. I got a Polar FT4. The HRM has my age, gender, height, and weight, as well as (obviously) my heart rate to track my cals, so I thought it would be very accurate. I used it for the first time today, and am pretty skeptical. I did a warm up walk for 10 minutes at 4 mph. At that point the treadmill said I burned 54 cals, and the HRM said I burned 70 something. Okay.. Moved on to my strength training for the day. Did core and upper body for 50 minutes. I had a good workout, but I am never extremely sweaty after a strength day. My HRM said i burned 451 cals! MFP says I burn 190 or something for 50 minutes of strength. That's a huge difference... I got the sensors very wet and everything, why is it so off? Did I just waste 100 bucks?

Jenni268

Bump! I'm planning on purchasing an FT4, so I'm interested in the answers.

ohohraptor

Also, I think it read my heart rate as faster than it really was. I took my own heart rate for a minute and it was at 70 something, and my HRM said 110. That's way off... Usually my resting heart rate is around 55, not sure why it was so high this morning.

arodriguez24

I would say heart monitors are more accurate than MFP or other machines, HRM calculates so many things that it will be more on point, its sensing how much work you put your heart though and such, It can be a little high but for the most part I think its the closet you can get.

LMG0511

I have a Polar F6 and have been using it for almost 2 years. I've never had an issue with it- typically my HRM measures LOWER than what the cardio machines at the gym say....does yours have a chest strap? If so, I would take what it says for truth. Maybe just double-check your stats and make sure they are accurate.

Also, your calories burned depend a lot on your current weight, and how healthy your heart is. I noticed as I lost weight, two things happened:

1) My heart rate would not get as high for the same activities.
2) My calories burned became less for the same activity.

I would keep on with your Polar and see how you feel in a week or so- your heart will continue to strengthen and I would bet your calories burned will decrease as well. Good luck!

Jillk1023

me too.... bump

arodriguez24

Also, I think it read my heart rate as faster than it really was. I took my own heart rate for a minute and it was at 70 something, and my HRM said 110. That's way off... Usually my resting heart rate is around 55, not sure why it was so high this morning.

if that's the case make sure the sensor is wet and its properly placed below the chest, sometimes it can get jumpy. I have the ft7 and its been pretty good so far.

TrainingWithTonya

Have you had any caffeine today? What about medications for allergies, asthma, etc.? Those will all increase heart rate in addition to exercise which will increase the calorie burn calculated.

Another thing to consider is that MFP's strength training MET level is for general exercise by people who are lifting light to moderate weights with rest between sets where the heart rate has a chance to go back down. If you are lifting heavy and/or not giving yourself adequate rest between sets, you will have an elevated heart rate through more of the exercise which will give you a higher calorie burn.

ohohraptor

I would say heart monitors are more accurate than MFP or other machines, HRM calculates so many things that it will be more on point, its sensing how much work you put your heart though and such, It can be a little high but for the most part I think its the closet you can get.

That's why I got it, but I don't know, 451 cals for 10 mins of walking and 50 of strength seems outrageous to me! Although it would be awesome if it were correct!

tnknights

MFP can't track HR. Someone put the formula in MFP. Calories burned depends on sustained Heart Rate. You can do the same activity twice for the same length of time and get different results. All depends on how high your HR stayed.

Trust the HR monitor more than MFP and enter the totals it gives.

melischemitz

I also have an FT4, and though I've never compared it to a machine or to MFP's calculations, I've put in the calories as it tells me and I've lost 7 lbs this month so it seems to be working! Also, I do zumba a lot, and I average 650 calories burned in an hour of that, and the norm is between 500 and 1000 so I'd say it's pretty accurate.

Mindful_Trent

HRMs are NOT meant to be used for activities like weight-lifting. They're only designed to be accurate for constant cardio activity like walking/running/etc. And not for "casual" activity like walking around the store or things like that. (They're not designed to be worn all day.)

There was a great post awhile back by Azdak, I think, about why you can't use HRM's for strength training calories burned, but I don't have it bookmarked...

ohohraptor

Have you had any caffeine today? What about medications for allergies, asthma, etc.? Those will all increase heart rate in addition to exercise which will increase the calorie burn calculated.

Another thing to consider is that MFP's strength training MET level is for general exercise by people who are lifting light to moderate weights with rest between sets where the heart rate has a chance to go back down. If you are lifting heavy and/or not giving yourself adequate rest between sets, you will have an elevated heart rate through more of the exercise which will give you a higher calorie burn.

I purposely didn't have coffee this morning because I wanted to see how accurate the monitor was. I don't give myself a lot of time between sets, although I don't lift heavy by far. I'm pretty weak still.

ohohraptor

Also, I think it read my heart rate as faster than it really was. I took my own heart rate for a minute and it was at 70 something, and my HRM said 110. That's way off... Usually my resting heart rate is around 55, not sure why it was so high this morning.

if that's the case make sure the sensor is wet and its properly placed below the chest, sometimes it can get jumpy. I have the ft7 and its been pretty good so far.

Can it get too wet? I got it fairly wet and positioned it right under my bra line. Maybe I'll play around with it more.

arodriguez24

I would say heart monitors are more accurate than MFP or other machines, HRM calculates so many things that it will be more on point, its sensing how much work you put your heart though and such, It can be a little high but for the most part I think its the closet you can get.

That's why I got it, but I don't know, 451 cals for 10 mins of walking and 50 of strength seems outrageous to me! Although it would be awesome if it were correct!

Yea that seems way too high, but like you said it was picking up your heart beats faster then it was when you checked, so make sure its placed properly. If its not giving you proper results after a while you may have a faulty sensor and you should contact the seller or polar.

ohohraptor

HRMs are NOT meant to be used for activities like weight-lifting. They're only designed to be accurate for constant cardio activity like walking/running/etc. And not for "casual" activity like walking around the store or things like that. (They're not designed to be worn all day.)

There was a great post awhile back by Azdak, I think, about why you can't use HRM's for strength training calories burned, but I don't have it bookmarked...

Really? I had no idea! I thought it worked for everything. Why is it not meant for strength training?

Mindful_Trent

This isn't the post I was thinking about in my comment above, but here's one I would recommend you check out:

http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472

ohohraptor

I would say heart monitors are more accurate than MFP or other machines, HRM calculates so many things that it will be more on point, its sensing how much work you put your heart though and such, It can be a little high but for the most part I think its the closet you can get.

That's why I got it, but I don't know, 451 cals for 10 mins of walking and 50 of strength seems outrageous to me! Although it would be awesome if it were correct!

Yea that seems way too high, but like you said it was picking up your heart beats faster then it was when you checked, so make sure its placed properly. If its not giving you proper results after a while you may have a faulty sensor and you should contact the seller or polar.

Will do, thanks!

JennyG73

Heart Rate Monitors will be more accurate than a machine or MFP because, as it's been said already, it uses you personal stats. I know when I set up my first HRM, neglected to set it for female so the numbers were off. (It's a female watch....who would have thought? lol)
Depending on the strength training you did, you can burn a ton of calories and depending on how much you sweat, not realize it. Next time you do your strenght training, periodically check your watch to see where your heart rate is. You'll see a higher number when doing lunges/squats because you are using large muscles, arm muscles are smaller and you won't see a spike.
Stick with it and keep track of your min/max hr for the different types of workouts and you'll see a pattern for workouts "work" you a bit harder.

ohohraptor

This isn't the post I was thinking about in my comment above, but here's one I would recommend you check out:

http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472

I'll check it out, thanks.

Mindful_Trent

HRMs are NOT meant to be used for activities like weight-lifting. They're only designed to be accurate for constant cardio activity like walking/running/etc. And not for "casual" activity like walking around the store or things like that. (They're not designed to be worn all day.)

There was a great post awhile back by Azdak, I think, about why you can't use HRM's for strength training calories burned, but I don't have it bookmarked...

Really? I had no idea! I thought it worked for everything. Why is it not meant for strength training?

Found it - here's the original post I was thinking of - though I do recommend you read that other one, too. http://www.myfitnesspal.com/blog/Azdak/view/hrms-cannot-count-calories-during-strength-training-17698