07-12-11, 09:20 AM | |
Join Date: Jul 2004
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Yeah, I wouldn't put much stock in your HRM's calorie burn estimate. The key word there is estimate, and often those things overestimate. I roughly halve the calorie burn number I get from my HRM (I get numbers like 700, too, and I suspect they're much more like 350); that's how much I think of its accuracy.
The HRM itself could have something going on. Mine recently started giving me different numbers than I had been getting; first the battery was dying, and then the chest strap seems to be going. So check those. Plus you can get interference from other HRMs and cardio equipment. Maybe the person next to you is wearing one that's causing yours to give you different feedback. I also notice that when I'm not feeling as well or not getting as much sleep or am warmer to begin the workout (whether because it's hotter out or because I've done something beforehand) my HR and thus calorie burn count go up more quickly, too, everything else being pretty much equal. So maybe you're just more rested on class days, or maybe the Zumba studio's a few degree cooler, too. But if your HRM is still good and none of those other types of factors are factors, it's very possible that you're fitter. In that case, congratulations, and keep up the good work!
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Kath I listen to my body and respond compassionately. - sankalpa from Jill Miller's Yoga at Home level 1, month 5 practice Note: I have had a professional relationship with a vendor of health and fitness books and media. For details please see my profile. |
07-12-11, 10:17 AM | |
VF Supporter
Join Date: Oct 2001
Location: Kansas City
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I routinely burn about 500 calories an hour doing Zumba, about the same as running; I don't think 700-800 is at all out of line for a 90 minute class.
I do suspect something is malfunctioning, though. Yeah, you burn less calories when you weigh less, and you burn less calories when you're more fit (therefore more efficient.) But the difference would not likely be THAT big or that sudden. You might need to get your battery changed. My HRM starts getting weirdly intermittent results when it needs a battery (rather than just going black suddenly.) The calorie burn is just an estimate; nevertheless, it should remain fairly consistent (or change slowly over time in a predictible way.) It isn't absolute but it should be relatively stable. |
07-12-11, 10:25 AM | |
VF Supporter
Join Date: Nov 2001
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Susan, I agree. The calorie burn for a 90 minute workout is definitely not out of line.
Weighing less and your body becoming more efficient during a particular workout does lower the amount of calories burned during a workout, but I think what you are experiencing right now is too much of a change, so it could be your heart rate monitor. If you are worried that you are burning less calories now, try switching up your workouts. I'm a huge believer in cross-training.
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Laughter is the best medicine. Have you had your daily dose? Walking is Nature's Prozac! Don't let anyone judge you! It's your workout. Sylwia Don't Compare Yourself to somebody else. BE YOUR BEST! Chalene Johnson A Spark of Hope In memory of: Michael Sparkman October 11th, 2001-October 21st, 2008 Hope Fimiani August 26th, 2006-October 13th, 2008 |
07-12-11, 10:57 AM | |
VF Supporter
Join Date: Nov 2001
Location: Illinois
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As your fitness improves, your HR for a specific activity will not get as high, and since that's what a HR monitor bases it's calorie burn calculations on, it will show a lower calorie burn.
I learned something quite interesting about HR at a racewalking clinic I attended: the standard "220-age" maximum HR calculation (which is what most heartrate monitors and gym equipment is based on) is off for most people. It was developed based on 50 non-exercising cardiac patients (and based on their peak HR during testing, NOT their actual max HR.) We did lactate threshhold workouts to get a better estimate of our max HR. I'm 54, but for machines and my HR monitor, I have to put in 39, which is my max HR based on the 220-age calc. An 80-year-old guy who was there had to use 29 years old!
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calorie burn counter, heart rate, heart rate monitor, heart rate monitors, hrm |
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