Riddle me this...

jennarandhayes

So, I use the elliptical often, and I wear my HRM while working out. The other day my husband convinced me to take a spin class. It was out of my comfort zone, but I kept up, and I was dripping with sweat throughout. My heart rate was higher while spinning than it is while on the elliptical. When the class was finished I looked at my HRM, and I burned fewer calories than I do while on the elliptical (same amount of time). How is this possible?

sijomial

How does the average HR compare for the two sessions?

Was the Spinning class intervals versus steady state on the elliptical?

Feeling hard isn't always a good indicator of actual calorie burn.
As an example if I do a steady hour on the bike at 150 watts it feels pretty easy, not breathing hard, not sweating much.
But my last workout was 8 minute intervals at 100 watts and 200 watts. Exactly the same power output (and therefore calorie burn) over the hour but intervals felt really hard and I was a sweating, gasping mess.

robertw486

So to clarify, you are using the HRM for calorie burn estimations on both workout devices?

If so, that might expose flaws in the device, or it might expose a flaw due to you being less comfortable on the spin bike. The spin bike isn't a weight supporting machine, and as such is more reliant on specific muscle groups for you to produce power. The elliptical requires you to support your weight as well as balance yourself more, so this engages different muscle groups.

The steady state vs intervals mentioned above could be a big factor. I've found that heart rate rise and the lag associated with it works differently on my bike vs on the elliptical. I can only assume this would equal out if I had similar power measures on the bike and adjusted my output accordingly. I've also found that day to day I have some variance even on the elliptical where I have power measure metrics in front of me. For that reason I think the average HRM device is subject to quite a bit of error myself. I know I can have a "range" of HR even when doing workouts at set time and very similar wattage average, even when I'm keeping things as level as possible and avoiding intervals.

The same applies to the sweat and perceived exertion factors. Some days I sweat quick with lower output. Other days I hardly sweat when killing it. Even with accounting for temperature differences and fan or lack of, there seems to be no sense to it. And the elliptical I use is in our home, so I can control all the variables. I'd bet that if someone took away all my data displays and I had to guess based on perceived exertion and/or the sweat factor I'd be off quite a bit day to day.

I've also found that on both the bike and elliptical, outputting at a high level brings my HR up as expected, but at some point if my HR climbs a lot, it also impacts major changes in how quick and/or far it ramps down. Though I don't have a device that gives me my average HR, I'd be fairly certain that if I get "behind the curve" on pace and have to make up time, my average HR would always show up higher than if I started out at faster pace and then gradually ramped down over the workout.

I also have the occasional day where my initial HR ramp up time is more variable. On average within about 9-10 minutes I'm fully warmed up and HR is more stable in relation to load. Every now and then it jumps up earlier at very similar loads, and now and then it takes a full 20 minutes or so.


@Azdak recently posted a thread showing how HRM vs machine could allow the HRM to be flawed with different workouts, yet very close for others. I'd have to assume that those same potential weaknesses in any HRM could just as easily be exposed machine to machine, even if you are only using the HRM to calculate the calorie burn.

blues4miles

jennarandhayes wrote: »

My heart rate was higher while spinning than it is while on the elliptical.

Your heart rate was higher when you looked at it? Or your average heart rate over the whole period was higher?

Azdak

jennarandhayes wrote: »

So, I use the elliptical often, and I wear my HRM while working out. The other day my husband convinced me to take a spin class. It was out of my comfort zone, but I kept up, and I was dripping with sweat throughout. My heart rate was higher while spinning than it is while on the elliptical. When the class was finished I looked at my HRM, and I burned fewer calories than I do while on the elliptical (same amount of time). How is this possible?

The only explanation is that the HR response to the spin class, or other factors such as actual time exercised are different between the two workouts. Or some technical issue (eg loss of contact with the chest strap).

The HRM can only respond to the signal it receives from the chest strap. It can't interpret what type of exercise you are doing.

jennarandhayes

blues4miles wrote: »

jennarandhayes wrote: »

My heart rate was higher while spinning than it is while on the elliptical.

Your heart rate was higher when you looked at it? Or your average heart rate over the whole period was higher?

My average was higher.

jennarandhayes

robertw486 wrote: »

So to clarify, you are using the HRM for calorie burn estimations on both workout devices?

If so, that might expose flaws in the device, or it might expose a flaw due to you being less comfortable on the spin bike. The spin bike isn't a weight supporting machine, and as such is more reliant on specific muscle groups for you to produce power. The elliptical requires you to support your weight as well as balance yourself more, so this engages different muscle groups.

The steady state vs intervals mentioned above could be a big factor. I've found that heart rate rise and the lag associated with it works differently on my bike vs on the elliptical. I can only assume this would equal out if I had similar power measures on the bike and adjusted my output accordingly. I've also found that day to day I have some variance even on the elliptical where I have power measure metrics in front of me. For that reason I think the average HRM device is subject to quite a bit of error myself. I know I can have a "range" of HR even when doing workouts at set time and very similar wattage average, even when I'm keeping things as level as possible and avoiding intervals.

The same applies to the sweat and perceived exertion factors. Some days I sweat quick with lower output. Other days I hardly sweat when killing it. Even with accounting for temperature differences and fan or lack of, there seems to be no sense to it. And the elliptical I use is in our home, so I can control all the variables. I'd bet that if someone took away all my data displays and I had to guess based on perceived exertion and/or the sweat factor I'd be off quite a bit day to day.

I've also found that on both the bike and elliptical, outputting at a high level brings my HR up as expected, but at some point if my HR climbs a lot, it also impacts major changes in how quick and/or far it ramps down. Though I don't have a device that gives me my average HR, I'd be fairly certain that if I get "behind the curve" on pace and have to make up time, my average HR would always show up higher than if I started out at faster pace and then gradually ramped down over the workout.

I also have the occasional day where my initial HR ramp up time is more variable. On average within about 9-10 minutes I'm fully warmed up and HR is more stable in relation to load. Every now and then it jumps up earlier at very similar loads, and now and then it takes a full 20 minutes or so.


@Azdak recently posted a thread showing how HRM vs machine could allow the HRM to be flawed with different workouts, yet very close for others. I'd have to assume that those same potential weaknesses in any HRM could just as easily be exposed machine to machine, even if you are only using the HRM to calculate the calorie burn.

Thanks!