if I ride on turbo at 25mph for say 10mins but use different gears will my heart rate stay pretty much the same?

basically am I still working at the same intensity just changing the cadence?

could be stupid question with obvious (to some) answer!

it’s not quite as simple.

you’ll be at the same power.

imagine spinning really fast (lowest gear), you don’t need much strength but you need to be able to apply it really quickly.

imagine spinning really slowly (highest gear), you need a huge amount of power but not very often.

as you slow it becomes more muscular output as opposed to cardio-vascular.

It should be higher at higher cadences. It depends on the level of intensity.

around threshold intensity. lets say I’m on a compact rd chainset with a 11-27 cassette

4th lowest cog / 5th / 6th

if I was to keep 25mph with these 3 gears

You will be producing the same power. But the way your body is able to produce that power changes. You’ll probably find there is a cadence band which you are comfortable producing and once you move outside it your heart rate will rocket.

So to answer your question will it say pretty much the same, then no.

More interestingly, why do you ask? You can play around with things like this and record it all and then produce interesting graphs in Excel. Quite how any of that makes you faster I have yet to find out. 🙂

well I currently use cadence to gauge my effort / heart rate

I know if I use a certain gear and 105rpm I will be at threshold within about 2 mins.

I also no what rpm I need for the next cog up and down the block to keep me at threshold.

so the aim is to stick to the rpm for all 10mins – as heart rate creeps up over the course of the session.

but what I notice is that the speed for all 3 gears in 93/103/107rpm is pretty consistent 25-26mph