I have a Timex Heart Rate Monitor that I like to use when I’m running or at the gym. The problem is that it is clearly overestimating the calories burned and I have no clue why.
This is supposed to be a good HRM, and I do have things set correctly (I have my actual weight programmed in, etc.). Now, I am overweight, so I realize I’ll burn a bit more calories than someone who is not. I also seem to be able to work out at a pretty high heart rate; when I’m running*, my heart rate will get to and stay at 180-185, with highs of right around 190 not unusual.
I’m a 26 year old woman and the HRM will tell me that after about 2 miles of run/walking (26ish minutes), I’ll have burned 673 calories! My circuit class** was 35 minutes, with my heart rate averaging 160bpm and it claims I burned 789 calories.
These CANNOT be right!
The rule of thumb for running or walking is ~100 calories for every mile. Even taking into account being overweight and working a lot harder, that would still maybe be 300 calories, not 673.
What’s going on here, and why is this so far off?
Which is still hard for me, and I space in walking parts.
** 12 stations of classic weights and calisthenics (bent over row, tricep dips, jump roping, mountain climbers, crab walks, shuttle runs, overheard presses, etc.), minute at each station, two full rotations.
I don’t have specifics but the calories-burned calculation for a device like that takes into account heart rate, and your exercising heart rate is high. I am a fit 51-year-old man and I have never exceeded 140 as a sustainable heart rate during cardio exercise (today I can sustain more like 135). My lowest rest pulse is 52. The average maximum heart rate for a 26-year-old is around 188. However, you exceed that during running, which would normally be about 85% of the max. Of course, this depends on your fitness level and rest heart rate, but it gives you the idea that your rate is on the high side.
My point is that your heart rate is outside the norm so the heart rate monitor is making assumptions that don’t work for you. Do you program in your rest pulse or maximum pulse (you don’t do this on cardio machines that give a calories-burned readout, so those are not too accurate either)? If not, then that is probably the explanation.
At 26 years old, the OP isn’t doing anything that the makers of a HRM would find unusual. Some people can do it and some can’t, but it’s not unusual.
That said, the HRM is certainly using some sort of algorithm that isn’t giving a realistic output. Either the Timex programming is crap, or the HRM is broken. Is it still under warranty? Can you take it back and try a different unit?
Yeah, my heart rate is high while exercising, but like you said, I’m young and it’s not totally unheard of. My mom thinks it’s weird, too, but she’s obviously older than me so has a lower target heart rate anyway.
Unfortunately I’ve had it for over a year, and I don’t think the warranty is there anymore. I just wonder if at least I can reliably say, “well, my actual calories burned are more along the lines of 1/3 or 1/2 (or whatever) of what the HRM says I burned”.
No, it’s not overtraining. And the potential for injury through running does not come from your heart. It is probably an unsustainable pace until you’re much more fit, however.
The advice that you might want to back down the pace and go for distance is solid, but unrelated to the question.
Most anything that doesn’t have a face mask is going to be unable to accurately measure calorie expenditure. As noted above, they’re all likely to be optimistic because people like kidding themselves. You know that running a mile uses roughly 100 calories pretty much no matter who you are or what shape you’re in (read again: “roughly”) and you know how much effort it takes to run that far. Use that as your gauge, not the HRM.
Your heart rate is not unreasonably high. It’s just above average.
I’m 26 and pretty fit, I can still top 200 on the right hill. It’s not comfortable in the least, but my heart rate goes that high. When running I will easily sit in the 170’s for a long time.
That’s why I do running and walking segments. The heart rate most definitely does come down when I walk. It only goes back up as I run. I splice both segments in so I don’t kill myself running and have gradually increased the length of the running segments. If I can’t do it, I back down and go easier. I’m following Couch to 5K (which I did back in 2006, but have to start over since I wasn’t able to run at all for quite awhile).
Maybe, but some better machines can probably do a better job of estimating. We have a Precor elliptical machine at our house that seems to do a decent job. By knowing the efficiency of the exercise (which tops at about 25% at the high end) and having a method of measuring power produced during the exercise, a reasonable estimate could be made. I’d like to think that something like a SRM power meter on a bicycle would be able to give you data to calculate a reasonable calories burned number*.
It’s not surprising that a $70 HRM doesn’t give as good a result as a $3,000 powermeter, but using both at the same time would be a way to get a decent conversion factor to apply to the Timex HRM. A visit to a gym with the Timex and using a high end machine with a good calorie burned function would give the OP a way of getting more useful data from the Timex.
*Of course, the people who can afford the SRM meters can also afford lab testing, so there is probably information out there on how accurate the SMR unit is to start with.
I’m not sure I trust the cross trainers either. The running machine at the my gym, which I assume is decent quality, tells me I’ve burned about 550 calories after a 30 minute run at 12 kph. Heart rate varies, but peaks at about 165 bpm. I find it pretty hard work and quite tiring. In contrast, 40 minutes on the cross trainer tells me I’ve burned approximately 660 calories, even though my heart rate is stable at around 130 and I don’t break sweat or do more than breathe tidally. Just my observations.
Of course, my suspicion is that the reason the cross trainers are so popular in my gym is their calorie count is extremely generous…
Checking a calorie calculator (I used this one: http://www.healthlinkbc.ca/kbase/topic/special/tx4394/sec1.htm It’s from the B.C. government, and cites the source for calculations - so I’m assuming that it’s somewhat reputable) - and according to that calculator, it’s possible to burn that many calories running at 5mph for 26 minutes if a person weighed about 400 pounds.
It seems that the 100 calories per mile applies only if you’re about 140-150 pounds.
Of course, I have no idea what you weigh, and I won’t ask - it’s just some more information to help you determine how far out of line your monitor is.
This is a good point, and I’d frankly forgotten about them. (Dunno why, I’m a cyclist, I should know this crap). Just like the face mask is measuring oxygen consumption, the SRM is measuring power output. The key word, though, is “output”.
Even the best heart rate monitor is still just counting and guessing.
It’s not an anomaly, just higher than the norm. If the unit does not require you to input your resting heart rate, weight, and body fat percentage, then it is probably missing something needed for an accurate calorie count.
I know that recent research says you burn a lot of the calories from exercise during the hour or so after you’re done with the outright exertion. At least some of the fitness coaches I’ve met during business networking are using this extra 50% or so to bump up their estimates of calories burned. (So, instead of estimating 100 calories for running a mile, they’ll tell you 150 by assuming an extra 50 will be burned after the run). I don’t know whether that approach is justified, just that it’s being used.
I don’t think those chest strap monitors are that accurate. I can’t see how it compensates for how hard you’re using your muscles, which is a major factor.
I threw mine on for a mountain bike ride once and it read 3,600 kcal spread over 3’30". It wasn’t an easy ride by any means, but c’mon, that’s more calories than I eat in 2 days. It’s not tough to get into the low 1,000’s if I’m training for a race or taking a yoga class or something. But a lot of that is more strength and balance training while I’m still recovering from an endurance session.
Mine seems to use lots of info: my age, sex, height, weight, different zones and exercise type, but it still just seems like a shot in the dark. I mainly like to use it to monitor my heartrate, so I always get excited when I set a new record for myself. I set a maximum of 206 on a bike ride near Telluride a few years ago and I haven’t been able to pass 203 since. But like it was said above, once you train enough, running in the 170’s for an extended period of time is quite doable.
I never could believe this, but I read it all over the place, so I never bothered to look it up. It looks like it’s not only not actually true, but not even really all that close.
I just wonder if at least I can reliably say, “well, my actual calories burned are more along the lines of 1/3 or 1/2 (or whatever) of what the HRM says I burned”.
The heart rate most definitely does come down when I walk. It only goes back up as I run. I splice both segments in so I don’t kill myself running and have gradually increased the length of the running segments. If I can’t do it, I back down and go easier. I’m following Couch to 5K (which I did back in 2006, but have to start over since I wasn’t able to run at all for quite awhile).
I think some of this is what physiology you were born with.