HRM Question (Polar)

So I went out and bought a new F4 Polar heart rate monitor, mainly because I want to know exactly how many calories I'm burning during my boot camp class.  I tried it today on a couple machines at the gym - 22 minutes on the treadmill and 20 minutes on the elliptical registered both in the upper portion of my training zone, but more importantly it told me I burned 497 calories.  Can that be right?  The machines, even after I set them to my height, weight and sex, usually are about 100 calories less than that for the same amount of time.

I'm 5'5, female, 198 pounds.

My HRM is usually pretty accurate, I think - hard to know what to believe.  If both are set for your gender and weight, I would be safe and take an average of the two readings.  The machines are not terribly accurate but I don't want to trust my HRM to be the accurate one and then end up eating too much.

You can't get an accurate calorie burned count from the F4 on treadmills or other gym equipment because the crosstalk (the disruptive electronic signals) throw off the reading.

Original Post by emilyd22222:

You can't get an accurate calorie burned count from the F4 on treadmills or other gym equipment because the crosstalk (the disruptive electronic signals) throw off the reading.

Don't the Polar models all come with encoded chest straps? Why would a machine effect the reading- also all the machines I use always check for chest strap especially since I don't use their hand monitors.  I don't even use the encoded strap anymore and just a cheap one I got with my basic HRM and it works fine.  I also don't worry about crosstalk because I don't exercise within 3 feet of others - in fact there aren't any others in my gym that use a HRM

My F4 has an encoded chest strap.  I think that number can be right.  Next time you work out look at the HRM every so often to see if it does any crazy jumps or drops in numbers - if it doesn't, it's probably a safe number.  

It says specifically in the manual of the F4, which relies on the encoded chest strap, that you will get crosstalk from gym equipment that has a built-in HRM.

Heart rate monitors calculate an estimate of calories burned based on duration and intensity of your workout just like the tables on this site or other methods of estimating calories burned.  The advantage the heart rate monitor has is that it can continually monitor your heart rate to determine intensity.  The more accurately it is set up, the more accurately it will estimate calories.  If the F4 relies on your age to estimate your maximum heart rate and uses this to define your intensity there is a good change that your margin of error is high.  This article helps to explain heart zone training and how to get a better estimate of you maximum heart rate.  Once you know what to use as a maximum heart rate you can program you HRM accordingly.  This should give you a more accurate estimate of calories burned. 

Note:  Some of the higher end Polars, like the F11, have a built in OwnZone test to determine MHR/VO2 Max to set your training zones for you.  Even if your HRM has this feature, I recommend that you do your own tests as described in the article to be sure that your are using your HRM most effectively.

tr is correct - I don't know what features the F4 has as far as the programming and getting it set up to You personally.  I have the F11 and run the fitness test at least once a month.  My fitness level has fallen a bit and its now harder for me to burn the calories I used to for the same workouts.  When I was doing more cardio and less weights my fitness level was elite and I could burn cals like no ones business, now that I do more weight lifting and less cardio my cal burn isn't so great.