Accuracy of Heart Rate Monitor

fatbegone85

I just purchased a heart rate monitor today so that I can accurate record my calorie burned, but I'm very skeptical of the number I got today. I worked out 21 minutes to Kendell Hogan's Cardio Challenge. I'm very out of shape and did sweat alot. I pushed myself today, but the 459 calories burned in 21 minutes seems very high. MFP puts my calories burned for Aerobic, High at around 262 calories. Is this normal?

My stats:

Age: 29
Height: 4'11
Weight: 212

HRM model: LifeTrak C300. Allows me to enter birthday, height, weight. Halfway through workout I checked my heart rate, it was at 170 bpm.

Ready2Rock206

Does it have a chest strap? If not then it probably isn't accurate. If it does you have a better chance of it being accurate.

Even the MFP # would be really high for me, but I am a low burner... :ohwell:

joansjourney

I agree that if it has a chest strap it is probably very accurate. I use a Polar and usually compare my actual burn versus what mfp says and it can be more or less. By the way.. I burned about 440 calories yesterday doing 31 minutes of yoga so your burn doesn't seem inaccurate to me. I'm on the bigger side too.

ChrisM8971

Unfortunately a HRM does not guarantee accuracy of calories burnt. Even though the one I use is a chest strap model I have to deduct my approximate NEAT burn from it for its estimates to fit with my weight loss. That is I deduct approximately what my body would be burning in the time I am exercising doing its normal day to day activity

If I am correct the one you have is not a chest strap model and is more of a fitness tracker than a HRM and unfortunately a few quick google searches suggests that the HRM part is not the most accurate

fatbegone85

Its a wrist model. I did read the reviews about the pedometer being too sensitive. But I rationalized that calories are calculated by heart rate, age, weight, height so that would still be accurate (as others in the reviews have mentioned). Sigh. I will return it tomorrow and just log Aerobic, High for my exercise today.

PinkyFett

Doesn't sound off to me, but nothing is perfect. Just a best guess.

When I first started, I did an hour on the treadmill at 2.5 MPH and burned 974 calories.

Today in a half hour at 3 MPH I did 301.

ChrisM8971

Its a wrist model. I did read the reviews about the pedometer being too sensitive. But I rationalized that calories are calculated by heart rate, age, weight, height so that would still be accurate (as others in the reviews have mentioned). Sigh. I will return it tomorrow and just log Aerobic, High for my exercise today.

Don't get disheartened because it is still worth having a HRM in my opinion.

Once you accept they are not always 100% accurate they are a useful tool to have

While everyone has their own idea of what is the best I think the cheap ones that appear in Aldi regularly are a good starting place. In the UK they are normally £14.99 and have a chest strap

fatbegone85

wow. 974 is a lot. What was your height and weight when you first started? Is there a way I can "test" the accuracy of the heart rate monitor----barring purchasing another and comparing?

davert123

To me that number is well off. its saying you are burning at 1300+ calories per hour. If you are out of shape right now (you wont be for long if you keep going so you are doing fab) I doubt if you will be burning more than 800 per hour . As you get fitter your body will become better at burning calories. The amount of oxygen your blood will carry will increase considerably and your lungs may become more efficient which means beat for beat (on your pulse) your body will carry more oxygen which means you will burn more. Have a look at the HRM and see if has a setting for fitness level and turn it down. Alternatively take it for a walk and measure the calories burned and then check with MFPs estimate. All these things are just best guesses but you will be able to compare like for like. Also you could go down a pay per go gym and work out on a machine there, noting how hard you are working on a machine and try and match the intensity you feel doing what you do and then compare calories.

Whatever you do, good luck and keep it up :-)

davert123

PS - MFPs estimate seems ok for you at the moment so you could just use this :-) You are doing great whatever

fatbegone85

I just did a series of tests with it (walking, jogging, full on running). Making sure to go back to resting heart rate in between times. I found that checking my heart rate while working out alters the calorie counter. It's weird. For instance it would read 10 cals, then I check my heart rate (was 162 at the time) it immediately tacted on 40 cals. It's ok, I'm going to return it. I've been eating at my calorie goal, so I feel OK. Exercise, regardless of the calories burned, is always a good thing.

bwogilvie

Most heart rate monitors are good only for estimating moderate to intense aerobic exercise, done at a consistent intensity. In other words, they work well if you are jogging or cycling at the same speed, rowing consistently, etc. For walking, interval training, etc., most are not very accurate at all. There are a few high-end models ($200 or more) that use Firstbeat, Inc., technology to do a better estimate of energy expenditure, but they are still not very accurate for start-and-stop exercise.

As a reality check: I'm a fairly fit 160 lb. guy (46 years old), and to burn 600 calories an hour (10/minute), I have to bicycle at 17-19 miles per hour on a flat course, or run a 10-minute mile. If your HRM claims that you are burning more than 7-8 calories/minute, and you are not drenched with sweat or feeling like you are really pushing yourself hard, then it's probably overestimating your calorie burn.

yungibear

I have the lifetrak c200 and my dad has this heart rate/oxygen level monitor for your finger. It's not accurate to a T, but it is close by around 5 bpm in either direction. The trick to the lifetrak watches is you have to take your heart rate reading every time you change the intensity of your exercises. If I am not able to get an accurate reading, I generally hack off around 50-100 calories, depending on how many times I've failed to get a good reading.

heybales

Its a wrist model. I did read the reviews about the pedometer being too sensitive. But I rationalized that calories are calculated by heart rate, age, weight, height so that would still be accurate (as others in the reviews have mentioned). Sigh. I will return it tomorrow and just log Aerobic, High for my exercise today.

Ya, purely guessing how it works unless you've done some research, that's not rationalizing, that's called throwing the dice. Odds are against it being anywhere near correct.

Ya, even Polar who pays for their own studies to improve the calorie estimates (it doesn't measure calories burned, it measures HR only) can be upwards of 15% off when using actual lab tested stats. Using their own device estimated stats, 35%.

Yours is probably using some public domain study (which could fine, several are good and Polar uses a one too) that may not be that good, but you wouldn't know.

http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study

But if you have access to a treadmill - you can at least test it.

http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

And if it doesn't test well, you can at least use it to tell you your average HR during the session, and come up with your own calorie burn formula.

http://www.myfitnesspal.com/blog/heybales/view/getting-your-personalized-calorie-burn-formula-663625

heybales

Doesn't sound off to me, but nothing is perfect. Just a best guess.

When I first started, I did an hour on the treadmill at 2.5 MPH and burned 974 calories.

Today in a half hour at 3 MPH I did 301.

Might confirm with something more accurate than HRM. Use the Gross option for comparing to HRM results.
Use NET for what you would log to actually eat back.

http://www.exrx.net/Calculators/WalkRunMETs.html

LSinVA

I think the number yours is giving you is pretty high for that short period of working out. I'd probably slash that in half or so. I'm 202 lbs and 5'2, so fairly similar stats to you and I get about the same HR (165-170) when pushing myself. I burned 540 today doing an *hour* of walking/light jogging at 3.0-3.5 MPH on my treadmill with an incline. TBH, my average for an hour of heavy cardio exercises is in the neighborhood of 450-550. The poster who said they did 974 can't be right unless it was 2.5 MPH at a really steep incline...

I highly recommend getting one with a strap. I bought my Polar FT4 on Amazon for about $60. It was easy to input my stats and you won't even feel the strap, trust me.

I actually tested mine against my treadmill and found my treadmill to be woefully inaccurate. It was recording my cal count far too low as it didn't take into consideration HR, age, weight or even incline/speed levels. It calculated based on distance only. It used a very basic formula to give a "general" calorie burn. My husband came up with the same exact numbers I did when he tested it. So I trust this heart rate monitor... even if it probably is still off a bit. You're never going to get an exact amount but this is the closest I've found.

PippiNe

Some time ago I bought a middle range HRM. After questioning its accuracy, especially for any exercise that was not done completely standing upright, I was led to the following website by another MFP member. It will calculate your gross and net calories burned. You will need to take your pulse a few times throughout your workout and enter the average bpm plus a few other things, like weight, age, etc. I've found these calculations to be reasonable and MFP friends with expensive HRMs also said the site's equation is pretty accurate. My HRM has been tucked in a drawer ever since.

http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

I'd suggest comparing your HRM readings to the results you get from this website. If they're close on a couple of workouts, your HRM is probably fine. If they're way different, I'd go with the Shapesense.com calculations. It takes a little extra time to plug in the data, but I think it is worth it.

fatbegone85

I have the lifetrak c200 and my dad has this heart rate/oxygen level monitor for your finger. It's not accurate to a T, but it is close by around 5 bpm in either direction. The trick to the lifetrak watches is you have to take your heart rate reading every time you change the intensity of your exercises. If I am not able to get an accurate reading, I generally hack off around 50-100 calories, depending on how many times I've failed to get a good reading.

That seems to be the issue for sure! I noticed every time I check my heart rate the calorie count would readjust themselves.

jnite

I just got a HRM as well but mine is coming in alot lower than what my treadmill says. I do 1/2hour on the treadmill and depending on what preset i use it says 177 calories burned, but my HRM only says 100-120calories burned. My HRM is a bowflex precision 7.0, and it is a chest strap.

yungibear

That's how the product works, though. I can't really see there being any other way to calculate the calorie burn without a chest strap. It's meant to be more of a hybrid device that isn't good for any one function, since it does track steps too. I suppose if you are looking for a dedicated HRM, it's a better idea to get one that just tracks heart rate and calories. As for myself, I've been getting a pretty close calorie burn reading to my TDEE, depending on how active I am. At my current weight loss stage, it's "good enough" and gives me an idea as to how much I'm burning each day.

caitconquersweight

I use a Polar FT4. It has a chest strap. I've found it to be a bit more accurate than what MFP gives me. MFP told me I'd burn like 800 calories doing an hour of zumba. Uhhhhh no lol. I burned about 450 doing an hour of zumba. Imagine how much it would sabotage me if I ate back 800 exercise calories!

MikeInAZ

Return whatever you got and get a Polar.

I use a Polar FT4. Today I worked out for 80 minutes doing running, weight lifting, and other gym activities. I burned over 800 calories according to my Polar. To me that seems about right.

A normal person is going to do around 100 calories every 10 minutes or so. Give or take depending on a lot of factors.

I highly recommend the Polar. It's cheap, easy to use. The chest strap is no big deal, and I don't even notice it's there. It's even waterproof. Also the Polar will show up on a lot treadmills and elliptical at the gym.

Check it out: http://bit.ly/polarft4

If you want a BlueTooth version to sync with different Apps, check out the Polar H7

http://bit.ly/polarh7

Leigh_b

Because I don't trust the calorie burn computation of HRM's I use this equation to figure out my burn based on my average heart rate over the time I have worked out.

(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.


This one is specifically for women - it's different for men - but using your stats and the 170 bpm it would have been a burn of 288.8 calories. You would need to know what your average heart rate over the 21 minutes was to see the real burn - but it would be far less than what your HRM is telling you.

I agree with everyone else, you should definitely get one with a chest strap. They are a bigger pain but worth the accuracy.

heybales

Because I don't trust the calorie burn computation of HRM's I use this equation to figure out my burn based on my average heart rate over the time I have worked out.

(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.


This one is specifically for women - it's different for men - but using your stats and the 170 bpm it would have been a burn of 288.8 calories. You would need to know what your average heart rate over the 21 minutes was to see the real burn - but it would be far less than what your HRM is telling you.

I agree with everyone else, you should definitely get one with a chest strap. They are a bigger pain but worth the accuracy.

Here's an easier way to to do that from the Polar funded study the formula came from. You can keep the web page up and just put in new minutes and avgHR.

http://www.braydenwm.com/calburn.htm

Problem there is it is still assuming a HRmax figure (220-age), and a VO2max figure if you don't have one to use.
The study is at the site.

fatbegone85

Return whatever you got and get a Polar.

I use a Polar FT4. Today I worked out for 80 minutes doing running, weight lifting, and other gym activities. I burned over 800 calories according to my Polar. To me that seems about right.

A normal person is going to do around 100 calories every 10 minutes or so. Give or take depending on a lot of factors.

I highly recommend the Polar. It's cheap, easy to use. The chest strap is no big deal, and I don't even notice it's there. It's even waterproof. Also the Polar will show up on a lot treadmills and elliptical at the gym.

Check it out: http://bit.ly/polarft4

If you want a BlueTooth version to sync with different Apps, check out the Polar H7

http://bit.ly/polarh7

Thank You. I did just that. Returned the LifeTrak and purchased a Polar FT4 since it seems to be getting very good reviews. Ill be trying it out for first time tonight. I'm excited. You know, buying gadgets like this actually makes me look forward to working out. Who'd a thunk it?

Aaron_K123

imo I find it funny that so many people refer to HRMs as super accurate but then always eat back only half of their estimated calorie burns to stay on track with their weight loss.

In my personal experience I think HRMs tend to vastly overestimate caloric burn. They are only supposed to be accurate during steadystate cardio which means only when you are in a tight aerobic range. They are not accurate for anaerobic activities like weight lifting and they are not accurate for activities that spike your heartrate like HIIT.

I have one, a polar with a chest-strap, but I don't trust it much. I generally go with the idea that the most I will ever burn is 10 calories a minute and that only if my heart is pounding out of my chest. I then just gauge my intensity based on my heartrate from the monitor or just on how difficult the workout is for me and either multiply each minute I'm in that intense range by 10 or if its less intense by a smaller number.

I end up logging most 70 minute intense workout sessions as something like a 500 calorie burn as a 6' tall man because there is always a warm-up and a cool down which makes the 70 minutes more like 50 minutes of full on cardio. I eat 100% of that back. Now if I just asked my HRM to tell me it would tell me I burned 1000 calories which I think is B.S.