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traineo Community / Off-Topic & General Chat / Heart rate monitor calories - accurate?
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Spyke M
Fitness Guru
Posts: 387
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 # Posted: 15 Jan 2008 07:50


I just bought myself a shiny new Sigma PC-15 heart rate monitor with just the right amount of bells and whistles to keep me happy. I got all my data entered into it (sex, weight...) and it counts calories burned as well.

Just wondering - the calories burned according to the monitor and the calories burned according to the machines I work out on have NOTHING to do with each other. I can only be happy if the monitor is the correct one - am I burning so many extra calories because I'm a fatty, or are the monitors' calorie count not to be trusted?

Example: 20 minutes intense stationary cycle (level 12/20, "mountain" program, 85 rpm constant) + about ½ hour weight training + 10 minute cooldown on the treadmill (2% incline 6 kph) today. According to the machines that would be about 250 calories + whatever I burned on the weights. According to the monitor I was at 450 calories burned already at the end of the bike ride... 945 by the time I was finished.

I (still) weigh 307 pounds, so maybe that's why?
Minu ~
The Master
Posts: 2592
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 # Posted: 15 Jan 2008 12:30


All I can share with you, Spyke is that when I began my journey to fit(er)ness, I just did the work and ate right. I have no way of knowing exactly what I was burning with each session, I only knew that the session had to be done, and that my weekly weigh-ins were telling me to keep it up.

Gadgets are great, and I too now have a heart rate monitor which I use regularly, (though only for bpm checks and for the chronometer), I just think that while these tools can be helpful, they can be equally distracting.
Cardio King
Fitness Guru
Posts: 1784
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 # Posted: 15 Jan 2008 13:07


I have a heart rate monitor that counts calories too, Spyke. But I agree with Minu on just doing what needs to be done. Try not to get too obsessed with numbers and concentrate more on workin' it when you're at the gym. I did that for a while before I got my monitor and lost a good 17 pounds. Of course, that was before I fell off the wagon and gained 25 pounds back


Jim Boone
traineo Regular
Posts: 55
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 # Posted: 15 Jan 2008 13:12


Interesting conundrum, on the bike, it's telling you how much energy is being spent moving the pedals, in this way it's not like real cycling as that would mean moving your mass up hills, but you arent, it's not associated with your weight. On the treadmill, you are supporting your weight though, and lifting it up a slight incline, so thats more likely to be reflected by the HRM.

Your puls will be quicker anyway due to your size, so that will confuse the HRM even more.

I'd go with the machine figures on the bike, the HRM is making a lot of assumptions.
Angie H
Fitness Guru
Posts: 718
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 # Posted: 15 Jan 2008 15:34


Is the bike using your heart beat and weight to calculate your calories? Do you input your weight in the heart monitor? If the first answer is NO, and the second answer is YES, I would tend to trust the heart monitor.



The reason is that a fit person at your exact same weight, going at the same speed on whatever piece of equipment will burn less calories. Why? Because their bodies work more efficiently at the exercise. Depending on where you are along the fitness curve, a simple speed calculation could be very accurate or very INaccurate.

If you heart rate monitor uses your current weight and heart beat, then it knows how stressed your body is and could more accurately count the calories burned. If you're fitter, your heart bpm is lower for a given exercise, and you burn less calories.

You need to have both your weight and your heart rate for a best guess at your calorie expenditure. A lighter person burns fewer calories than a heavier one. If you have doubts, go strap a 50 lb weight to your torso and go running.

Hope that helps!
Angie H
Fitness Guru
Posts: 718
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 # Posted: 15 Jan 2008 15:35


Another thought: your weight DOES affect your calories burned even when on a stationary, because your LEGS are heavier, unless you have an odd body shape. It takes more energy to move them up and down compared to a smaller person.
Spyke M
Fitness Guru
Posts: 387
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 # Posted: 16 Jan 2008 07:29


I'm aware that the monitor is basically just a gadget and I shouldn't trust it to tell me EXACTLY how many calories I'm burning, but it's one of the ways I measure my progress - I mean, if my monitor tells me I'm only burning half the calories that I did yesterday, then I need to step it up!

The other reason I'm using it is that I need SOMETHING to report to traineo when I'm finished working out


Sheryl Azaroff
traineo Newbie
Posts: 19
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 # Posted: 22 Jan 2008 04:53


They're not accurate. Have a look at this http://www.nytimes.com/2007/12/20/health/nutrition /20BEST.html
Paul Bunning
traineo Newbie
Posts: 3
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 # Posted: 14 May 2008 22:36


The good heart monitors can be quite accurate -- I recently took my Polar F11 on a 2,000-mile bike tour. It said I burned 65,000 calories. In checking with research in the bicycling community, it is dead-on. (The average cyclist burns about 33 calories per mile.)

The neat thing about a personal monitor is you can equate different workouts, on different machines. I find most elliptical machines are
way, way over-optimistic (by 40% to 25%). Stationary bikes are better, and treadmills even better. But all these vary greatly by brand or model.
With the heart monitor you can ignore these differences.

The heart monitor is a great learning tool. Pedalling indoors always feels harder than outdoors -- but the monitor shows outdoors burns more calories! The main thing is it teaches how important intensity is. Even on a favorite stationary bike, normally in close agreement with my monitor, on those days I decide to read a mystery, the bike will claim I've burned 450 calories in an easy hour. The heart monitor, though, says 300.

It won't let you cheat.
Angie H
Fitness Guru
Posts: 718
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 # Posted: 14 May 2008 23:36 - Edited by: fauxvirgo


Interesting that you say that about ellipticals. I'm used to ellipticals telling me I'm burning around 600 calories per hour. My gym has brand new ellipticals by Matrix Fitness that register about 300 calories per hour. My heart rate is the same on both so I'm assuming they should be really close to the same in intensity. The Matrix Fitness treadmill registers nearly identical calories burned for 130-ish heart rate as the Traineo calculator. So, it does make me wonder if I'm burning closer to 300 vs. 600 on the elliptical.
Paul Bunning
traineo Newbie
Posts: 3
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 # Posted: 15 May 2008 19:01


You raise the issue perfectly -- the readings vary so much from machine to machine. I think lower readings are more likely to be accurate.

Even without a calorie-counting heart monitor you can test the accuracy
in a general sense. Most people sweat pretty profusely at 600 calories
per hour. At 300 they might only have a "glow." At 600 per hour their
heart rate would probably be 80% of their max or so. (About like jogging
six miles.) At 300 it might be just 60%. (About the same as walking 3.5 miles.)

So, if I drape my arms over the handbars, turn off the fan because it makes me too cold, read a newspaper for an hour -- I know the elliptical is wrong when it says I am burning 500 calories...
zeb r
traineo Regular
Posts: 52
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 # Posted: 16 May 2008 11:03


I've noticed a massive difference between machines and my polar f11 aswell

They're nifty gadgets though. I dont use mine for the post workout cal stats as much as I use it during the workout to gauge my intensity
Clifford Chinn
Fitness Guru
Posts: 470
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 # Posted: 16 May 2008 19:37


My thinking about this, besides agreeing with Minu 100%, is that as long as you're using a consistent device to measure, that's all that matters since, like you said, it's not so much the exact numbers you should be concerned with, but the trend.

There are just too many different factors into how many calories you're burning, which leads to lots of different equations and formulas and devices so, like people are pointing out, one device is going to give you a different value than another; if you use the same one every time then you'll at least have a consistent means of measurement... whether it's accurate or not should matter less.
Paul Bunning
traineo Newbie
Posts: 3
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 # Posted: 17 May 2008 07:48


Now that we have put that discussion to bed... has anyone used their heart monitor calorie-counting device during sex? Or during a dental cavity filling? (Or both at the same time? Weird.)

I kept mine on during a flu and discovered I burned a huge amount of calories with a fever although I doubt it was accurate.
Minu ~
The Master
Posts: 2592
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 # Posted: 17 May 2008 10:37


I had mine on once while brushing my teeth, (which I do "quite vigorously", as has been pointed out ; ), and had the bpm's up to 100! Cracked me up as my resting rate is around 45.

I reckon it'd be a turn on for sex too as everytime hub sees me undressing apres-workout and notes the strap around my ribcage, he ALWAYS says something whooohooooo-ish.


Phil Mcly
traineo Fanatic
Posts: 158
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 # Posted: 17 May 2008 17:15


Quoting: fauxvirgo
nteresting that you say that about ellipticals. I'm used to ellipticals telling me I'm burning around 600 calories per hour. My gym has brand new ellipticals by Matrix Fitness that register about 300 calories per hour. My heart rate is the same on both so I'm assuming they should be really close to the same in intensity. The Matrix Fitness treadmill registers nearly identical calories burned for 130-ish heart rate as the Traineo calculator. So, it does make me wonder if I'm burning closer to 300 vs. 600 on the elliptical.



What can be shocking is the difference between a personal HRM and a treadmill HRM, for example.

The treadmills at my gym routinely measure 10-20 bpm below my personal HRMs (Garmin and Nike Triax C8). That's a huge difference. And the gym treadmills very one form the other. That has led me to badly underestimate my HR at the gym, until I figured it out. (More on that in another post sometime).

That said, personally I use the traineo system of "perceived effort" over time for judging calories burned, and the HRMs for measuring HRM only.
Holly G
traineo Newbie
Posts: 5
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 # Posted: 18 May 2008 04:42


It's funny that I just happened upon this thread. I just bought a HRM(Polar F4 for women) this week and have used it in my last two work outs. I think it's one of the best tools I've ever bought. After purchase you personalize it to yourself by inputing your height, weight, sex and age. It then calculates where your fat burning zone should be. As well it tells you(beeps) when you aren't working hard enough or if you are working too hard.

As for being accurate you have to wonder how accurate an elliptical or treadmill can be by just getting your heart rate from your hands while you are moving. I found the elliptical machine that I have in my home never went past 130 when I was really working my ass off(as in drenched in sweat) and I could never get past 20mins on it. While using my HRM I found that I was actually over exerting myself when the elliptical still said only 120-130bpm. This would explain why I felt so tired and couldn't use it for that long.

Last night I used it for 45mins. The elliptical said I had burned 332 cals where my HRM said I had burned 497 cals. I was tired but I didn't feel like I had before when I was apparently over exerting myself to get the HRM on the machine to go up.
Holly G
traineo Newbie
Posts: 5
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 # Posted: 18 May 2008 04:45


Another thing...when I posted that I had done 45mins on the elliptical on traineo I had posted it as hard....since it fest hard to me. When I changed it to medium it said the total cals was 490cals . That's pretty damn close to the 497 cals my HRM predicted.
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