How accurate are heart rate monitors?

I had heard that machines can be inaccurate so I decided to try a HRM. I went swimming at a good kick for a half hour, and it told me I only burned 250 cals! On CC, it tells me a burn over 350 for 30 minutes at a light effort, so I was completely demoralised!

The question is...which is accurate? I'm confused and annoyed now. I tested my HR several times during the workout, and it told me anything from 120 to 230 BPM at the same instensity level!

FYI, I am 26YO F, 5'7" 193 lbs.

You know, I experienced the same thing with swimming.  I felt like I was working hard and I hardly burned any calories.....

You shouldnt be getting such a huge range of heart rates though....Do you have the kind that has chest strap as well as watch part???

I find mine to be HUGELY accurate (polar brand)

~H~

I also have a chest/wrist type polar-brand monitor and I checked it with the treadmill I like to use at the gym....both the treadmill and my monitor were right on track with each other!!  It is very important to know your max heart rate and your target heart rate.

I use this heart rate formula that came with the monitor.....

220 minus age gets you the MAX HEART RATE.....

Light intensity workout range are .50 to .60 of your max rate

Light MODerate to MODerate is .60 to .70 of max rate...

MODerate to HEAvy intensity is .70 to .85 of max rate.

I'm a 56 yr old male and I go to about light to moderate range...

DON"T go to your max rate....

 

Good luck....

Paul

i'm not sure what heart rate monitor you have but mine is a polar one and in the instructions it says that it is much less accurate in water.

from my experience this is the case as it works almost flawlessly when i'm doing normal activities, but when i'm swimming it goes slightly crazy...

hope you sought yours out... if its not working like it should, perhaps you should take it back?

I have a Polar and I don't think it's all that accurate even out of water.  I will do a workout and it will say I burned 200 cals, then I do the same workout later and it says I burned 500 or so.  The second didn't feel harder and I didn't do anything different...I don't know what to believe =\

It also doesn't change when my heart rate does.  I can feel my heart pounding a lot faster sometimes but it will tell me it's the same as if I were standing still.

I don't get it.

It also doesn't change when my heart rate does.  I can feel my heart pounding a lot faster sometimes but it will tell me it's the same as if I were standing still.

I don't get it.

 You may want to tighten up the chest strap.....when I started losing inches around my chest area, Mine started to act a little goofy, so I tightened the strap so it's snug and it worked like a charm!

Also, make sure the electrodes under the chest strap are dampened with water before you start working out.  Otherwise, it will NOT work correctly.

~H~

I'm starting to think perhaps this was a waste of money. The brand is Mio. I never heard of it, but I don't think that is relevant. I am thinking it might go back because it doesn't seem to be worth it if it isn't accurate. I thought this would clue me in as to how much I am burning but it just confused me more!

Haley: I wear the chest strap as tight as it will go and it seems to fit ok I guess.  Sometimes it slips up or down or my bra will move it a bit...so that could be the cause?  Do their straps come in different sizes?

I make sure I wet down the band and my skin under it before I start, but do I have to keep getting it wet?  It does dry out after a couple minutes...

Dawniecampbell-I also have the mio heart monitor watch, and I was pretty mad at how much it said I burned on my stationary bike.I do 30 mins on my bike and it say that on my bike I burned 700 calories .I had to bike for 45 mins just to burn 376 calories according to the hmw.So yeah I do not know which one is right. Maybe I should take my watch back too???

If i'm not mistaken, the strap should fit snuggly around the chest and shouldn't really move during exercise.  When I lose a bit of weight, i notice it moves around and the numbers go all whacky so it's time to tighten it up...then it works fine again.

I only have to wet mine at the beginning of a work out so I'm not sure what to tell you about that.  All i know is, when I'm done working out, i'ts VERY wet under there lol

I make sure my bra is sitting on top of it to give it more stability as well..

as for jellybelly, I would say that 700 calories in 30 is next to impossible.  The 376 in 45 minutes seems MUCH more accurate!

~H~

I can only speak for Polar as I have never tried other brands.  I own 3 of them!