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# Heart Rate Monitor--Overestimating calories?

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LOGICALLIE
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6/10/13 3:28 P

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SLYSAM
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6/10/13 12:45 P

Oh, on the maximum heart rate thing. On my Polar it is a setting the user can alter but it is in a second layer of "optional settings" along with resting heart rate and vo2max. If your watch has a built in fitness test it may be similar since those three stats are stats the hem calculates or estimates from formulas and from the fitness test. I think mine just uses the standard 220-age type formula to estimate max heart rate and that estimates very high for me personally (sprinting up stairs I never get close to it). But for some people it can really dramatically underestimate max heart rate. This link shares another formula in question 5 and says it usually ends up within 10-20 beats of a users max heart rate. 10-20 beats is quite a difference, but it might give you ideas on how much to add to what Polar estimated. www.webmd.com/fitness-exercise/features/th
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SLYSAM
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6/10/13 12:31 P

Usually heart rate monitors estimate calorie burn based on what percentage of your estimated max heart rate you reach. Many use the average heart rates. Your hrm estimated max heart rate is probably lower than your actual max heart rate. Just from what you mentioned about having a higher resting heart rate and was it 167 average heart rate during this walk? (Sorry we don't have a quote option). If you can, change those in your settings.

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MOTIVATED@LAST
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6/8/13 4:44 A

Yeah, those HR numbers seem substantially higher than average for a run/walk. And as population averages are used by HRM's to calculate calories, your HRM will be overestimating calories burned as well.

As a reality check,I agree with Dragon's rough guide of 100 calories per mile walked (slightly more than this for running), so 220-250 seems not unreasonable.

An alternative reality check is that most people can expect to burn 6-10 calories per minute of exercise. 6 at the moderate end (walking), 10 for more vigorous, and perhaps 12 if you were running fast. Say an average of 8 for a run/walk - again the mid 200s for 30 minutes.

M@L

The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

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MEGAPEEJ
Posts: 608
6/8/13 12:01 A

Darn, I was really liking the idea that all that effort wasn't only 250 calories, LOL!

I couldn't really say I'm "heavy" - I'm 5'10" so am within a few pounds of my normal BMI (hooray!). But not so overweight that I could be expected to burn double the predicted calories in a well studied activity.

That's a drag, I was really looking to get a more accurate reading with a HRM.

Do something everyday that your future self will thank you for.

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DRAGONCHILDE
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6/7/13 8:05 P

Running/walking is a well studied exercise, so you can be assured that you're fairly close depending on the weight. Your HRM does sound like it's overestimating... by a LOT. A rough estimate of the calories burned on a mile-long walk is about 100... obviously, it'll be a bit more if you're heavy, a bit less if you're lighter or very used to it. 220-250 is more what I would expect.

If your heart rate is higher, that can definitely throw things off.

Heather
Writer, mother, wife, and breadwinner. I love to run, but running doesn't love me, so I'm switching to my low-impact bike.

I'm not pregnant, just fat: My blog.

fatnotpregnant.blogspot.com/

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MEGAPEEJ
Posts: 608
6/7/13 5:41 P

I do however have another question related to an HRM overestimating calorie burn!

I recently got a Polar FT7 HRM, and on my first 2.5 mile 30 minute walk/jog interval, it told me I burned 420 calories, where Spark estimates 220, and the machine 250. I added a bit of an incline, plus Spark assumed I walked the whole way because that's pretty slow. BUT, I have a high resting heart rate, so my average heart rate was 171 with the max hit of 181. So my HRM probably thought I was killing myself exercising that hard, but it would show someone more fit, lower heart rate as not having burned as many calories. For the record, when I walked the first 5 minutes and my HR was 145-150, the calories on the machine and my HRM matched exactly. It was when I started jogging (and the walk intervals in between, because my HR stays above 170 until cool down) that the difference sky rocketed.

Does someone with good heart rate/calorie burn knowledge look at these numbers and think "yeah, that makes sense", or does my calorie burn seem high based on the fact that my heart just beats faster?

Edited by: MEGAPEEJ at: 6/7/2013 (17:43)
Do something everyday that your future self will thank you for.

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DRAGONCHILDE
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6/7/13 5:33 P

FEM_PHOENIX1109, regular heart rate monitors will definitely overestimate if you leave them on for regular activity. They're not designed for use all day like the Fitbit or Body Media. They're only designed to measure cardiovascular activity. The formulas for other activities (non-cardio and strength training) doesn't have the same relation to heart rate, so it's nto going to give you an accurate estimate of your daily calorie burn.

Heather
Writer, mother, wife, and breadwinner. I love to run, but running doesn't love me, so I'm switching to my low-impact bike.

I'm not pregnant, just fat: My blog.

fatnotpregnant.blogspot.com/

 current weight: 190.6

 211 197 183 169
155

MEGAPEEJ
Posts: 608
6/7/13 5:29 P

Your heart rate is not the cause of calorie burn - it's an effect when you're doing something else that is burning calories. As such, HRMs are completely inaccurate for tracking calories when not doing cardio. My heart rate increases when I go from sitting to standing, when the cat sneaks up on me and slaps my ankles, when my phone rings - none of these things burns any extra calories, but an HRM will see the heart rate and assume you're doing something active to increase it (because that's all those poor silly HRMs know).

Do something everyday that your future self will thank you for.

 current weight: 176.0

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FEM_PHOENIX1109
Posts: 20
6/7/13 4:22 P

I just got a heart rate monitor with a calorie counting feature, and I think the calories burned are way too high according to this thing. I left it on all day just to see how much I was burning throughout a normal day, and by evening time it was already over 4000 calories!

I think I may have one setting set up wrong though. When entering my data, it asked me for a low and high boundary, and I'm not exactly sure what that mean. Would the low boundary be the 50% of max heart rate and the high boundary 75%? Or is it something different than that?

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DMARTIN302
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2/16/13 4:44 P

The other posts have given you some really good information. I will chime in saying that my calories counted by an HRM (Polar, Garmin, and Zephyr are ones I've tried) always are calculated at a lot more than the machine says, and far more than what SP says (almost double what SP says). I'm 50 years old, 153 pounds, and my exercise heart rate while running or cycling averages 144 (including warmup and cool down) with a max between 161-169 depending on the class/workout. (My resting heart rate is 43.)

I was using my higher HRM numbers to plug into SP, and I wasn't losing any weight. About 4 months ago, I went to recording SP's lower numbers into SP and keeping a spreadsheet with SP's and the HRM's numbers separately so I can compare. According to my calculations, I really AM burning the calories on my HRM. Now all I have to figure out is how to burn MORE calories! :)

So, yes, your HRM may be right. It's a lot of work to track SP, the machine, and your HRM calories burned and compare them with what you eat, then compare the different calorie deficits to your actual weight loss. But if you do that for several weeks, you'll see which one is the most accurate FOR YOU (because, ultimately, that's who matters to you!).

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MOTIVATED@LAST
Posts: 13,277
2/15/13 10:45 P

High blood pressure and some medications can lead to an increased heart rate above what the exercise itself justifies. This can lead to the HRM overestimating the calories burned.

You may also want to double check your weight and age settings in the HRM.

One possibility may be to calibrate your HRM against walking. Walking is a fairly well studied and understood activity, and online calculators are reasonably accurate - this may give you a basis on which to compare what your HRM reports.

M@L

The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

 current weight: 178.0

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 SP_COACH_NANCY SparkPoints: (158,833) Fitness Minutes: (112,042) Posts: 46,222 2/15/13 8:27 P Hi MATHMANDA,Calories expended is determined not by heart rate alone, but is actually the amount of oxygen the body consumes in relation to large muscle activation which in turn creates a greater demand for oxygen and other nutrients, which in turn causes an elevated heart rate. Anything outside a laboratory setting is just an estimate. This includes the readout on the machines, the calorie calculator here on SparkPeople and your heart rate monitor. The more data you can input into the equation, the more precise your calorie burn figure will be. My suggestion to you is use the data based from your heart rate monitor. If after 3-4 weeks you do not see any changes, you may want to re-evaluate your calories burn figure. I hope this helps!Coach Nancy

MATHMANDA
Posts: 55
2/15/13 7:24 P

I started working out with a Polar heart rate monitor last week (it's the type with a chest strap.) When I do a workout, it tells me I burn significantly more calories than the machines (The elliptical today said I burned 500, the heart rate monitor said 655.) I always thought the number from the machine would be the highest. Is this a problem anyone else has?

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