Exercise! - My heart rate monitor vs. the elliptical

08-28-2007, 08:41 AM
Today I used my heart rate monitor that Polar just sent back to me with a new battery and checkup.

Every morning I do 45-46 minutes on the elliptical. It says I burn 390-405 calories, and my heart rate according to its sensors, hovers between 120-125. Not so! According to my HR monitor, I burned 293 calories and never got my heat rate above 89 :o I KNOW the calorie count on the elliptical is a guesstimate, but WOW! What an eye opener. Tomorrow I need to do a manual pulse check, because that seems really odd.

I suspect the truth is lurking somewhere in the middle. Sooooo....beware using machine counts and relying strictly on the numbers!


08-28-2007, 09:55 AM
Mel, the 89 heart rate has to be wrong. I go above 89 just walking up the stairs from the locker room to get to the elliptical.

The gym Precor says that I burn about 415 calories in 30 minutes, based on my age, gender, and weight. I usually average 150 bpm for the 30 minutes but do intervals that spike into the low 160s. My Polar HRM says that I burn about 246 calories using the same info. I totally believe my HRM over the machine.

08-28-2007, 11:56 AM
I get the same experiences, gym elliptical vs home elliptical. Gym elliptical (Lifefitness or Precor) tells me I burn over 400 calories in half an hour, heart rate is measured on palms, heart rate is in the high 100s (160-180).

Home elliptical (Lifefitness) tells me I burn a little over 200 calories in half an hour, heart rate is measured through chest strap, heart rate is in the low to mid 100s (120-150). Funny thing is though I always thought my workouts at home were more difficult than the gym workouts so it is disheartening :)

08-28-2007, 12:12 PM
I think you might need to send the HRM back :(

The elliptical at my gym gives wildly inaccurate calorie counts--over 800 calories for a 30 minute session. According to my HRM, it's much closer to 300. The treadmill, conversely, gives a much closer estimate--if I put in my weight, it's usually within 30 or 40 calories of my HRM. If I don't put in my weight, it too gives me overinflated estimates.

08-28-2007, 12:21 PM
The displays on the recumbent bikes in our gym are closest to my HR monitor, Precor ellipticals are way off, and the LifeFitness crosstrainers are ridiculously out of control on their calorie counts. So what do all the gym members do? Yep, fight over the crosstrainers because "they burn more calories". The manufacturers are geniuses for inflating the numbers. I've told members that they're burning the same numbers of calories when their heart rate is the same on different equipment and they simply don't believe me.

08-28-2007, 12:40 PM
The manufacturers are geniuses for inflating the numbers.

It would be nice if it were regulated though. Surely there is some basic Heart-Rate to Calories Burned formula; I don't know on what grounds they can just make up numbers...

08-28-2007, 12:53 PM
I don't really pay attention to the calorie counters. I go by distance on my recumbrant bike, as I've heard that the calorie counters are incorrect on the majority of the exercise machines.

08-29-2007, 12:36 PM
Mel, could it be the chest strap that's wonky instead of the watch part, since the watch just came back from Polar? Do you have another chest strap you could try it with?

Machines are notoriously inaccurate and your 125 from your machine readout seems awfully low to me (and 89 is laughable). I was watching my HR (per HRM) this morning and I hit 125 when I was 49 seconds into my warm-up. I have to think your HR goes higher than that during 45 minutes of cardio. :) Unless you're doing your nails and talking on your cell phone. :lol3:

08-30-2007, 10:40 PM
Hahaha! The only person who is awake when I do cardio is you, Meg, so I'm not talking on my cell phone.

I played with my monitor which now tells me my resting heart rate is 36 :faint: I doubt that I'm up in the 150's because the resistance on my elliptical is semi-dead, but I'm now positive that the monitor is going back to POLAR! I'm at least moving quickly. A fast walk on my treadmill brought my hr up to about 120 in 3 minutes according to the treadmill sensors.

So now I have an elliptical that doesn't work and a hr monitor that doesn't work :?: The planets are just not aligned these days!


08-30-2007, 11:47 PM
No indeed! Mel, this is a tragedy! I thought you worked in a gym...?

I find that some of the treadmills at my gym play up a little bit with the heart rate. My watch will tell me 157, which feels right, and the treadmill display will be variously reporting 87 (ie, asleep), 189 (heart attack) and 154. It's annoying. I'm pretty sure that I'm the only person in my gym dorky enough to wear an HRM (ha!) so I think it's just the machine. But still....

08-31-2007, 05:41 AM
"Dorky enough to wear a heart rate monitor"? Hey, I resemble that remark! :rofl:

Yes, indeedy, Mel, you're officially near dead with a HR of 36. Guess you can call off work today. :lol: