Can I really burn as many calories as my HRM says?
spintronicus
Posts: 45 Member
I have a fairly accurate HRM (Polar) according to the reviews. But my husband always makes me second guess. Then again, he didn't believe that I can lose weight with eating more. Anyhow.
So here's the deal. The winter this year is more brutal than the years before and kids and I try to take advantage of all the little opportunities we can, aka any day with a degree above freezing. Weekend was warmer (40F), so I packed the kids into our Chariot CX2, got into my running gear and we headed outside. I wore my HRM and started it the moment we left the drive way. For reference, their combined weight is around 60lbs, but we also packed water bottles, snacks, blankets, their polar bundlers, etc. We weren't able run much due to snow and ice but I pushed and pulled the jogger for about an hour before I took a shopping break. At some point I had to slowly push the stroller down to a snowy hill and had to use the breaks since the hill was somewhat steep. When returning home, I couldn't push the kids up the hill, so I pulled them up and rested every few steps. I'm telling this because that particular hill was the hardest. The sidewalks were covered with snow too. It took about an hour for us to reach the mall, I shopped for about 45mins while pushing sleeping kids in the jogger, and the return took about 1:15hours. By the time we were home my HRM said 3 hours exactly and 2115 calories. Max heart rate 195, average 150, lowest 90. My resting heart rate upon waking up is around 40. I'm 5'6", 30 years old, about 140lbs. And again as a reference, the same HRM gives around 250calories for 25minutes of 30 day shred with a max HR of 185 and average of 140-150. My husband says there's no way on earth I can burn 2000 calories only with exercising. What do you think?
So here's the deal. The winter this year is more brutal than the years before and kids and I try to take advantage of all the little opportunities we can, aka any day with a degree above freezing. Weekend was warmer (40F), so I packed the kids into our Chariot CX2, got into my running gear and we headed outside. I wore my HRM and started it the moment we left the drive way. For reference, their combined weight is around 60lbs, but we also packed water bottles, snacks, blankets, their polar bundlers, etc. We weren't able run much due to snow and ice but I pushed and pulled the jogger for about an hour before I took a shopping break. At some point I had to slowly push the stroller down to a snowy hill and had to use the breaks since the hill was somewhat steep. When returning home, I couldn't push the kids up the hill, so I pulled them up and rested every few steps. I'm telling this because that particular hill was the hardest. The sidewalks were covered with snow too. It took about an hour for us to reach the mall, I shopped for about 45mins while pushing sleeping kids in the jogger, and the return took about 1:15hours. By the time we were home my HRM said 3 hours exactly and 2115 calories. Max heart rate 195, average 150, lowest 90. My resting heart rate upon waking up is around 40. I'm 5'6", 30 years old, about 140lbs. And again as a reference, the same HRM gives around 250calories for 25minutes of 30 day shred with a max HR of 185 and average of 140-150. My husband says there's no way on earth I can burn 2000 calories only with exercising. What do you think?
0
Replies
-
I'm asking this because I had the instinct that I needed to eat significantly more that day but couldn't bring myself to. I had a protein loaded dinner though. I also had a double dose of my protein shake upon arriving home. The whole course except inside the mall is around 4-5miles. Half is paved, half isn't.0
-
Will be interested to see what other responses you get, but in my experience HRM are pretty useless for anything that isn't steady state cardio, and for that reason I don't ever use them. I'm a crossfitter so am constantly changing pace, strength, movements etc and HRMs don't account for anything other than your heart rate, which is a small part of the equation when doing weights/resistance training, intervals, etc.
Anyway. It sounds like what you were doing was a mixture of steady state with some intervals (harder hills, etc) so it might not be TOO far off, but you must remember to factor in the amount of calories you would burn at rest. For example, if you wore your HRM for an hour while sitting on the couch watching TV, it will still tell you you've burned calories. That number could be anywhere from 70-100, but let's say you're burning 100 calories at rest (for easier numbers). Factor that in to your 3 hour journey, and suddenly your calories burned from exercise is down to 1800. Then divide that by 3 and you get ~600 calories per hour, which isn't too far off the figures you get from doing the 30 day shred.
It does sound like a lot of calories (I don't trust the accuracy, but it will at least give you a ball park figure) and given that you were active non-stop for 3 hours, with some hard work and resistance from pushing/pulling your kids, you probably should have eaten more that day but I'd suggest that you rely less on your HRM and more on how you feel and what your gut tells you. If you feel more hungry, eat more. If you instinctively know that you've worked harder and should fuel more (which you say you did), then follow those instincts. I think people get too caught up in the numbers when using things like HRMs and they can actually be to your detriment. You obviously have an understanding of eating more to fuel performance and recovery, so just give yourself some credit and listen to what your body is telling you
0 -
With that kind of fitness level, maxHR 190 seen during the workout, resting HR 40, and using a Polar, which you don't state what model, I'm going to say you actually burned more.
If that is the more expensive Polar with VO2max self-test, and you select the athlete level and can enter in HRmax stat with a value obviously above 190 - then it's likely pretty accurate. From experience, probably 5%.
Since it gave minimum, it probably is nicer one, so just depends on values in it.
The VO2max self-test starts getting inaccurate the more fit you are.
Since it's also somewhat based on your BMI, it'll underestimate VO2max with higher BMI than considered good.
The cheaper models just assume if bad BMI, bad VO2max and fitness level. Those you would be very under-estimated on.
Now, the nature of the workout probably meant some of those high HR's was anaerobic from lifting, not getting there from cardio, so that spike and recovery high HR was inflated calorie burn, but with an avgHR 150, it wasn't up there that long.
But 2000 calories in 3 hrs pushing / pulling extra weight - pretty sure that's on the low side, you likely burned more.
As Jordy mentions though, that would still be gross calories burned during that time.
For purposes of thinking if you ate enough - like this is well over your exercise planned in your TDEE, and so thinking about eating it all back (good idea BTW), you want net, not gross burn.
And for being in a diet, all your time you are already expected to burn so much already that your eating is based on.
TDEE / 24 for every hr.
Subtract that from any extra exercise you do beyond what you included in TDEE, that you plan to eat back.
And your stats are very close to mine, better resting HR though, I'm only down to 45.
I have tested HRmax of 194, I'd bet you'd get there or better with proper test.
My VO2max test and Lactate Threshold of 176, VO2max 59.5. (the Polar VO2max self-test gave 52 I think).
I can gross burn 1000 cal / hr with HR avg 152, which is about mid-Aerobic zone going by % of LT, or lower Tempo zone going by % HRR.
Net burn of 1000 would need gross of 1083, and that would be avgHR of 159.
Which is very possible for about an hr. Going over that time by a lot though the avg is going to drop. But hitting 2000 in 3 hrs very easy.
Outside of HR, you could see what pace you'd need to hit for 667 cal/hr (2000 / 3hrs) running, with these formula being more accurate than HRM for running speeds 5-6.3 mph level. Incline can go up to maybe 3% and speed 7mph for still as good as HRM, but beyond that personal efficiency starts creating bigger differences.
The problem here is you were pushing extra weight, but that's not the same as carrying it.
It counts, but only on uphills and acceleration. Once moving, just increased drag from the chariot. And downhills it's a help.
http://www.exrx.net/Calculators/WalkRunMETs.html
So for 140 lbs, gross would be 5.9 mph level to burn 670 calories. (less resting metabolism net 604, not the same as I described above though).
So you could do that speed of run and get your avgHR for about 20 min. That HR then obtained on almost anything else will be the same calorie burn.
So if your effort with the kids felt harder than that pace running by yourself, and mostly with HRM and HR was a whole lot higher - yes the HRM is underreporting calorie burn.
Might try this with HRM to see how close it is.
http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is
And as Jordy mentions, if you know you did big effort, especially if you know you have a workout the next day, eat up as you did.
But unless you are doing massive sessions like that all the time (I do during training so I better have good idea), or throw in a big whopper of unexpected workout and eat back to feel good again, normally it'll be taken care of in the weekly averages.0 -
I seriously don't remember the model but will check tonight. It does have a self test mode and about 6-7 years old. The chest part is two pieces, fabric strap and electronic part which has its own batteries. I also have a timex that came with a machine but it usually overestimates my burn compared to the polar. My husband got himself another polar with bluetooth which is a newer model so maybe next time I'll try that on. I don't have a smartphone to connect it though.
I asked this because during the summer I was highly active, running with kids 3-4 times a week in the same route but obviously with no snow, eating a lot less than I do right now and I was unable to lose a single pound. When the winter hit, my activity level dropped to sedentary but I also cut back more calories and started gaining weight. I'm just trying to understand this whole issue without religiously counting calories. I still do but lately life got in the way and I'm not 100% accurate in my numbers. I'm still maintaining though.
I'll type the rest up after feeding the family.0 -
I checked the model last night and it's F11F. It's customized with my stats. I usually don't go above 185 without losing my breath but I didn't realize the amount of effort I was putting into moving the stroller since I was also busy with being alert of the snow, ice and the people/vehicles around us.And your stats are very close to mine, better resting HR though, I'm only down to 45.
I have tested HRmax of 194, I'd bet you'd get there or better with proper test.
My VO2max test and Lactate Threshold of 176, VO2max 59.5. (the Polar VO2max self-test gave 52 I think).
I can gross burn 1000 cal / hr with HR avg 152, which is about mid-Aerobic zone going by % of LT, or lower Tempo zone going by % HRR.
Net burn of 1000 would need gross of 1083, and that would be avgHR of 159.
I'll try the self test again with the HRM. I'm curious of the results. I don't know where else I could get tested for these or if my insurance covers.Outside of HR, you could see what pace you'd need to hit for 667 cal/hr (2000 / 3hrs) running, with these formula being more accurate than HRM for running speeds 5-6.3 mph level. Incline can go up to maybe 3% and speed 7mph for still as good as HRM, but beyond that personal efficiency starts creating bigger differences.
The problem here is you were pushing extra weight, but that's not the same as carrying it.
It counts, but only on uphills and acceleration. Once moving, just increased drag from the chariot. And downhills it's a help.
The thing with the path we run is that it's a constant up/down hill (where I need to push the breaks but yes, it's easier than uphills) with awful sidewalks until we reach to the pond we run around, then it's a mix of mud, gravel, and broken paved roads in between. There's maybe a few hundred yards where I can freely push Chariot. I have to constantly maneuver it. I'm glad we got the chariot due to the suspension it provides for the kids. They happily sleep in their seats. I wouldn't dare to bring our regular stroller there. In that sense, we aren't steadily running since my pace has to change frequently. I might try to run alone there to see how I do, though. Over the summer, the very same HRM was giving around 800 for an hour of running. This is without the shopping break and with no snow. Usually with HR stats of min 110, max 185, avg 140-150.It does sound like a lot of calories (I don't trust the accuracy, but it will at least give you a ball park figure) and given that you were active non-stop for 3 hours, with some hard work and resistance from pushing/pulling your kids, you probably should have eaten more that day but I'd suggest that you rely less on your HRM and more on how you feel and what your gut tells you. If you feel more hungry, eat more. If you instinctively know that you've worked harder and should fuel more (which you say you did), then follow those instincts. I think people get too caught up in the numbers when using things like HRMs and they can actually be to your detriment. You obviously have an understanding of eating more to fuel performance and recovery, so just give yourself some credit and listen to what your body is telling you
I definitely agree on not relying on an HRM too much but I'm still learning to listen to my body. Especially, as a woman I was always told to eat less, move more, and eat even less at some point to keep healthy and "skinny". After I was diagnosed with thyroid disease, I got a referral for a nutritionist and she told me that I had to eat dangerously low to stay at the weight I desired back then. Lately, I don't log as much as I used to like when I was doing low calorie dieting and hopefully will find a balance with all this.
0 -
Since you saw a 190 maxHR during a workout, and not one specific to trying to hit max, I'd suggest you manually set the HRM stat for HRmax to 195 easily.
That's not a zone alarm or level, but personal stat.
Make sure you do the VO2 self-test after a rest day as their FAQ says. And confirm weight is correct prior to that. And Athlete level actually if it asks that.
Insurance usually doesn't, unless you got a heart problem. Total vanity to see improvements from training, with side benefit of getting best calorie burn figures.
So yep, lot of resistance on your route, because even normal downhills takes more energy than up (stepping farther down gives increased mass due to acceleration) plus holding the stroller back.
Remember that comparisons of a routine is really pretty useless going by calorie burn, as that relies on a bunch of other stats that may change.
Use your HR stats as you've been giving compare, it'll be more interesting too.0 -
I deduct 20% from what my HRM says.0
