Clydesdales/Athenas (200+ lb / 91+ kg) - Calorie calculators on the net vs. HRM statistics

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Black Shuck
08-20-08, 10:23 AM
For those of you that have HRM's, are you getting results anywhere near the tables found here and there on the net?

I've been looking at a few and most claim that I shoul burn off 850-1000 kcal/hour at 26-30 km/h and I find this a bit much, as do my more active friends(runners, professional officers). I'm a borderline clyde riding a steel touring bike for training at the moment.

I know even HRM's aren't all that exact as your fat/muscle balance and other factors play in but is there anything to these tables? I'm trying to count calories consumed and burnt off to lose a bit more than I've been doing over the summer.


HuffyMan
08-20-08, 10:49 AM
Basically the HRM, I have a Polar F6, computes your calories off of an equation stored in a chip using one variable-your heart rate. So its accuracy is dubious without a lot of other information. I don't use it for its accuracy but rather its consistency. When I'm wearing my HRM chest strap I can compare the calories burned on the wrist unit and on the elliptical machines at the gym. The wrist monitor shows calorie consumption about 30% less than the display on the elliptical machine which also reads the chest transmitter.
The best use of the HRM is to compare your workouts to one another coupled with additional data from you bike computer and any other recorder you may have.
My main use for the HRM is to determine how fast I recover after an extended effort, and to see if I'm improving on my "test hills".
The charts say that my MHR should be about 177 and when I really hammer it, that seems to be fairly correct. However, I feel like I could keep up at 160 all day.
It's simple enough I guess, If you're keeping a very accurate record of calories consumed and your HRM shows more calories burned and you're still gaining weight. The HRM calculation is wrong or you're retaining a lot of water ;).

mhuntwork
08-20-08, 12:06 PM
I have a Timex Ironman Triathalon. I scale in at 240 and I have my unit programmed for 190 and sometimes I think it is still counting high!

At least with this weight it matches the gym equipment pretty well.

On the bright side I never have interference problems since most people use Polar units.


Black Shuck
08-20-08, 01:23 PM
Yeah, I'm going to go whith 700 Kcal/hour as a random suitably low number for my rides, even going whith that I'm 1400 kcal poorer after todays ride ;-)

59.06 km 1:59:02

(Edit, 1400kcal, not 14000 ;-))

evblazer
08-20-08, 02:33 PM
Oh if only those HRM or online calcs were right I'd be skin and bones :thumb:
Bikejournal says I'm at 338,690 kcal for the year. Woo hoo 96 lbs!! well er maybe 6 :cry:

All my HR monitor is good for is to see if I'm really slacking off during a ride.

squirrell
08-20-08, 03:05 PM
Basically the HRM, I have a Polar F6, computes your calories off of an equation stored in a chip using one variable-your heart rate. So its accuracy is dubious without a lot of other information. I don't use it for its accuracy but rather its consistency. .


I have a Polar F6 and it requires you to input your age, sex, and weight--so aren't all those factors taken taken into consideration when it figures your calorie expenditure? I know that the Polar is always lower on calories burned than any website I check.

dscheidt
08-20-08, 04:41 PM
For those of you that have HRM's, are you getting results anywhere near the tables found here and there on the net?

I've been looking at a few and most claim that I shoul burn off 850-1000 kcal/hour at 26-30 km/h and I find this a bit much, as do my more active friends(runners, professional officers). I'm a borderline clyde riding a steel touring bike for training at the moment.

I know even HRM's aren't all that exact as your fat/muscle balance and other factors play in but is there anything to these tables? I'm trying to count calories consumed and burnt off to lose a bit more than I've been doing over the summer.

Well, heart rate monitors work on the assumption that energy use is roughly linear with heart rate, from rest to the anaerobic threshold. That's generally true, though the rate increases a bit as you move away from resting heart rate. So if you increase your heart rate from 100 to 110, you're burning about 10% more calories. The problem is that there's a fair amount of variation on what that number of calories is, even among people of the same age, sex, weight, height, and level of fitness.
With meters on machines, there are other problems. One is that machines aren't often calibrated right. Even when it's right, they're measuring power output. If you're producing 200 watts, you're putting out about 175 calories an hour. Depending on how efficient you are at turning food into output power, that's somewhere between 700 and 900 calories an hour. That's nothing to do with fitness, it's just that some people are better at moving than others. There's additional variation due to familiarity with an activity. The first time you try and row a boat, you're going to be remarkably inefficient, and burn more calories than you will when you know what you're doing.

Charts (and online calculators based on them) are based on average energy use for the activities.

The really accurate way to do this is to measure the amount of oxygen you're using, by measuring the C02 output. That's not exactly practical if you don't work out in an exercise lab.

squirrell
08-20-08, 05:00 PM
Well, heart rate monitors work on the assumption that energy use is roughly linear with heart rate, from rest to the anaerobic threshold. That's generally true, though the rate increases a bit as you move away from resting heart rate. So if you increase your heart rate from 100 to 110, you're burning about 10% more calories. The problem is that there's a fair amount of variation on what that number of calories is, even among people of the same age, sex, weight, height, and level of fitness.
With meters on machines, there are other problems. One is that machines aren't often calibrated right. Even when it's right, they're measuring power output. If you're producing 200 watts, you're putting out about 175 calories an hour. Depending on how efficient you are at turning food into output power, that's somewhere between 700 and 900 calories an hour. That's nothing to do with fitness, it's just that some people are better at moving than others. There's additional variation due to familiarity with an activity. The first time you try and row a boat, you're going to be remarkably inefficient, and burn more calories than you will when you know what you're doing.

Charts (and online calculators based on them) are based on average energy use for the activities.

The really accurate way to do this is to measure the amount of oxygen you're using, by measuring the C02 output. That's not exactly practical if you don't work out in an exercise lab.

All that taken into consideration--and I do know that I burn A LOT less calories now than when I started riding in April. Not only am I better rider now but have lost 55 pounds to boot, so that translates into less calories burned.

But, again. all that taken into consideration, just how many of my exercise calories should I be figuring are legit?

It's important to me because I allow myself 1200 base calories to get my caloric deficit for weight control-which means I eat most if not all of the calories I burn. I've been losing weight but lately it's been sporadic.

So, how much should I take inaccuracies of HRM into account? For example, today I rode 65 miles (a personal best long distance!). It took 5 hours and 11 minutes. My Polar says I burned 2953 calories. A couple other websites say I burnt up as much as 3800 calories. I went with 2953--now, I can't eat that many calories obviously and do it in a healthy manner but have eaten about 1800 of them.

So, again, what kind of percentage should I figure is accurate? Or is it possible to even look at it that way?

HuffyMan
08-20-08, 05:25 PM
I have a Polar F6 and it requires you to input your age, sex, and weight--so aren't all those factors taken taken into consideration when it figures your calorie expenditure? I know that the Polar is always lower on calories burned than any website I check.

The equation is comprised of those factors that you enter. Much the same as the data you enter on a calorie chart website. The only variable after that point is the live analog input of the HRM transmitter.

Sammiches
08-20-08, 06:15 PM
All that taken into consideration--and I do know that I burn A LOT less calories now than when I started riding in April. Not only am I better rider now but have lost 55 pounds to boot, so that translates into less calories burned.


But remember your resting metabolism is probably burning more calories throughout your day now than it was back in April.

I pretty much gave up trying to get an accurate number of calories I burn on the bike. I just get confused at all the different answers and assumptions.

dscheidt
08-20-08, 06:42 PM
So, again, what kind of percentage should I figure is accurate? Or is it possible to even look at it that way?

Sort of. It's likely every time your HRM says you burned 3000 calories, you really burned M * 3000, where M is some percentage of that. It might be 70%, it might be more, it might even be over 100% of that. But it very much depends on you, and the HRM. The numbes are based on average results, and few people match them. I also suspect that many overstate, because it makes people feel good.

mhuntwork
08-21-08, 06:22 AM
I also suspect that many overstate, because it makes people feel good.

Haha! You can take that to the bank.