Higher HR on an "easier" bike?

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DaCookieMonsta
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Joined: 2 Jul 2022, 12:26pm

Higher HR on an "easier" bike?

Post by DaCookieMonsta »

Hi all, I have a silly question that has me curious and I'd like some info

I use a Garmin watch to track my HR while commuting to and from work and for a while I used a 29er with knobbly mtb tyres averaging 9-10mph. After 2 days of consecutive riding my legs were toast.

Last week I started using a hybrid with 700c x35 tyres, now I average 10-11mph with the ride feeling less taxing on my legs meaning they're no longer toast after 2 days consecutive riding.

But what had me floored, was that despite the rides being same distance/hilly routes, feeling easier and being quicker- my HR is approx 10bpm higher on average using that bike than on the 29er.

What gives?
PH
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Re: Higher HR on an "easier" bike?

Post by PH »

So what happens if you ride the easier bike at the same HR?
My guess is you'll half the speed difference.
I'd also guess that what's happening is the the bike feels more responsive to the effort being put in, which encourages you to do so. It's the same as riding with a tailwind, if that's on the way out you have to be careful not to overdo it.
Nearholmer
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Re: Higher HR on an "easier" bike?

Post by Nearholmer »

Although things like tyre rolling resistance, and position on the bike make a lot of difference to comfort and what might be called “ride experience”, most of the work you do actually goes into lifting weight (self, bike, & luggage) from one level to another, or put more simply: going up hills. On a route with any significant changes of level, the work done in lifting mass will dominate over work done overcoming various resistances.

If you go up the same hills, but faster, all other things being equal, you will be operating at a greater power output, which demands more oxygen, which means breathing harder, and the heart beating faster.

If you back-off effort on the easier bike, so go at exactly the same speed as on the previous one, you should see a tiny reduction in HR due to lower rolling resistance and more efficient stance, but getting everything so precisely the same (wind, temperature, how much breakfast you had, how much sleep the night before etc) as to allow this to be measured may well be impossible in practise.
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Paulatic
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Re: Higher HR on an "easier" bike?

Post by Paulatic »

I agree with PH re responsive bike more effort.
Also are the handlebars lower?
My own findings (These figures will not transfer to you. I’ve a very low HR,avg 92 for a couple of hours hilly riding.) Tops to drops HR increases by 3 Tops sitting to standing increase 5 beats.
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Tigerbiten
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Re: Higher HR on an "easier" bike?

Post by Tigerbiten »

What's your cadence on both bikes ??
Are you going faster by pushing a higher gear or by spinning the same gear faster.

I can hit 30mph one of two ways down the same hill.
Either I spin a 135" at 75 rpm or spin a 100" gear at 100 rpm.
Now 75 rpm is right in the middle of my optimal cadence range, so spinning at that speed doesn't alter my heart rate.
But 100 rpm is outside my cadence range, so spinning at that speed raises my heart rate.
So one option is your spinning a little fast for your level of fitness.
As you get fitter then your cadence range will get wider and you won't notice the difference as much.

Luck .......... :D
axel_knutt
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Re: Higher HR on an "easier" bike?

Post by axel_knutt »

What's your HR if you go back to the MTB?

If it goes back down, then it's probably just because you're riding slower, if it doesn't then it might be because your "legs were toast" after only two rides. If you're new to cycling don't be tempted to go at it like a bull in a china shop, follow a training program that starts easy and builds up gradually.
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Jdsk
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Re: Higher HR on an "easier" bike?

Post by Jdsk »

axel_knutt wrote: 2 Jul 2022, 5:57pm What's your HR if you go back to the MTB?
That's what I'd want to know. This would control for one of the many variables.

Jonathan
atoz
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Re: Higher HR on an "easier" bike?

Post by atoz »

When I invested in a Wahoo HR monitor and cadence sensor (and later as a 60 birthday present to myself, an Elemnt Bolt cycle computer) it was an eye-opener. Turns out despite advancing years and not huge mileages, I have a habitually high cadence rate (can be up to 122 on the right terrain). I have quite low resting pulse rate and BP in the ideal category. Sadly, doesn't make me team Ineos material though.

And yes I checked the accuracy of the cadence sensor by doing a quick manual count. I did suspect my high cadence rate years ago, that's why my highest gear is just over 100 inches, and lowest is around 18.
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