Losing faith in HR monitor for calories burnt

ConicalFern

rileysowner wrote: »

WalkingAlong wrote: »

3dogsrunning wrote: »

EvgeniZyntx wrote: »

rileysowner wrote: »

HR monitors are only accurate as an estimate for steady state cardio. While a bike ride could be steady state, I know in my rides there is a fair amount of variation due to the fact that there are hills, valleys, wind, and even changes in road surface. All of that makes it less true steady state. Add to that the inevitable HR drift that comes from long periods of time spent at an exercise activity which will skew the results, and the HR calorie estimate gets less and less accurate.

Sorry no - newer HR monitors using variance in HR analysis are as closer to energy use for non-stready state cardio including lifestyle activity. See the FirstBeat research for this. They report a maximal error of 7-10%.

Also, wasn't the issue with non-steady state cardio that you would get overinflated estimates due to the HR going up and down?

OP, I'd hardly call 1678 feeble.
Personally, I err on the side of caution and go with the lower one. If you really want, split the difference.

I was thinking this as well. That's about 450 calories per hour.

Then again, the METS value for cycling that fast is 12, which would be way more than 450 calories per hour.

Are you sure you went that far? That's 18mph for almost 4 hours.

I have never done it in the winter, but I know once I get back into the groove in the late spring and summer I can average 20mph on 2-3 hour rides on my mountain bike, sometimes more. With the snow and ice we have in the winter, if I dared to ride, I am guessing it would be far below that. It doesn't seem unrealistic if one rides a lot.

That's certainly speedy, especially on mountain bike. I don't know many people that could do that on a road bike.

WalkingAlong

WalkingAlong wrote: »

rileysowner wrote: »

WalkingAlong wrote: »

3dogsrunning wrote: »

EvgeniZyntx wrote: »

rileysowner wrote: »

HR monitors are only accurate as an estimate for steady state cardio. While a bike ride could be steady state, I know in my rides there is a fair amount of variation due to the fact that there are hills, valleys, wind, and even changes in road surface. All of that makes it less true steady state. Add to that the inevitable HR drift that comes from long periods of time spent at an exercise activity which will skew the results, and the HR calorie estimate gets less and less accurate.

Sorry no - newer HR monitors using variance in HR analysis are as closer to energy use for non-stready state cardio including lifestyle activity. See the FirstBeat research for this. They report a maximal error of 7-10%.

Also, wasn't the issue with non-steady state cardio that you would get overinflated estimates due to the HR going up and down?

OP, I'd hardly call 1678 feeble.
Personally, I err on the side of caution and go with the lower one. If you really want, split the difference.

I was thinking this as well. That's about 450 calories per hour.

Then again, the METS value for cycling that fast is 12, which would be way more than 450 calories per hour.

Are you sure you went that far? That's 18mph for almost 4 hours.

I have never done it in the winter, but I know once I get back into the groove in the late spring and summer I can average 20mph on 2-3 hour rides on my mountain bike, sometimes more. With the snow and ice we have in the winter, if I dared to ride, I am guessing it would be far below that. It doesn't seem unrealistic if one rides a lot.

Wow, 20mph on a mountain bike. I'm just slow. Though I think a friend's riding group does average 17mph, he said.

The idea of 12 METS for hours straight is odd to me but I kind of doubt you guys who can do that speed for that distance are really at 12 METS. To me, that's 'puke in a bucket' exertion. I remember Cathe Friedrich saying about 10 METS was most peoples' max for a tough, hour long cardio session.

Some other 12 METS activities are skipping rope, 120bpm and running 8.3mph, for context.

tincanonastring

ConicalFern wrote: »

tincanonastring wrote: »

ConicalFern wrote: »

tincanonastring wrote: »

3dogsrunning wrote: »

WalkingAlong wrote: »

3dogsrunning wrote: »

WalkingAlong wrote: »

Wow, I'm surprised you need to worry about your intake at all with that sort of activity, assuming it's not a rare event!

If you want a third estimate take your BMR per minute X 12 METS times minutes of the ride. It's going to be higher than both of those, I think. Even with my puny BMR it'd be over 2200 calories.

I worry about my intake at that level of activity because I don't want to undereat.

The OP said he didn't want to overeat. I can see it both ways. It just seems like if you can do that sort of athletic feat, I figure you must be Superman, and Superman should be able to eat freely without calcing out his burns and measuring his food. Clearly I'm no Superman, and not around many!

I also don't want to overeat but I want to eat enough to support training and to lose a bit of weight.
I haven't done too many 4 hour rides, but I still counted when I did.

I was so mad when I blew through my calories after running a half. I finished the run and thought I could eat for days without blowing through that burn. Lolz.

How many was that?

I'd have to go back and look, but it was a decent amount. I'm fat and slow; average pace, IIRC, was 10:10, so the run duration would have been close to 2:10:00.

At my weight that's 2486 according to Runner's world . I guess on the upside, it's rare that you can eat that many calories and and not actually go over your allowance by too much - imagine eating that much of a non-exercise day!

My Polar HRM that day showed a burn of about 1950 for 137 minutes. I think that's a little slower than 10:10.