Heart Rate Monitor Experiment

AuntieKT

I have a Polar FT4 heart rate monitor with accompanying chest strap. I have been using it for a couple of months now and really like it. Ever since I got it though, I have been wondering how many calories it would say I burned all day on a regular day with no workout. I was thinking that maybe it would be close to my TDEE or something. I am a 30 year old woman weighing around 165 pounds and I am 5'3". Though this may seem like a lot of weight for my height, but I actually have a fairly muscular frame and I have actually consulted with a nutritionist and she thinks that this is a good weight for me. Well, this weekend I did a little experiment. I wore it to bed in Friday night and set my alarm for midnight. At midnight I turned it on. When I woke up around 9:00 my monitor already said I had burned like 600 calories. I wore it all day. I had to take it off when I took a shower before going out and had to actually restart it again after that cuz it wasn't monitoring good when I put it back on for some reason. I figured I could just add the two readings together. At the end of the night at midnight I shut it off. So my grand total for 24 hours it said I burned 3050 calories. I'm not sure what to think about that. It seems awfully high to me. Is that what TDEE is? A measure of all day, or should I just have done the hours that I was awake? I am going to be transitioning to maintenance here soon and I was trying to get an idea of what I would eventually, gradually work my way up to in calories...but this seems ridiculous! What do you guys think about my experiment? Do you think it was way off base? If yes, does this mean that I shouldn't trust the calorie reading that I am getting when I use it regularly when I exercise? What does everyone think about this?

Mokey41

The algorithms on HRM's are set to calculate on elevated HR's. You know, when it says you're in the "zone". They are not accurate at lower rates and were never meant to be worn 24/7. For that kind of thing you need a BodyBugg or FitBit that are set for lower HR's.

skylark94

You're asking it to do something it is not designed to do. I don't wear my HRM for anything that doesn't get my HR above 120.

For non- workouts I wear a Fitbit. I'm 5'4", 36 yo, and weigh 132. My TDEE (sedentary) is about 1800 calories. On workout days I get closer to 2400.

AuntieKT

Thanks Pals. I didnt know that about Heart Rate Monitors. That's good to know. After this experiment I was a little worried about the accuracy of the calorie burns that it gave me for my workouts, but now I feel a lot better about it. I don't plan on wearing it 24/7 all the time. I was just curious about what it would say. Thanks for the information!

samanthawarren

The algorithms on HRM's are set to calculate on elevated HR's. You know, when it says you're in the "zone". They are not accurate at lower rates and were never meant to be worn 24/7. For that kind of thing you need a BodyBugg or FitBit that are set for lower HR's.

Do you know how accurate they are when you are in the zone? I just figured out how to set my weight on mine. I usually start timing when I am warmed up a little HR around 125. Before I set the weight it said I burned about 740 calories doing 65 minutes of Hot Hula Fitness. Today after setting the weight accurately it says I burned 1145 calories in the same time. Can their really be that big of a difference? The previous weight was set at 154lbs. My actual weight is 240lbs.