Calling sports scientists…

JungleBiker said:

Is it true that, all other things being equal (speed, power output, terrain, wind, etc), a cyclists heart rate will slow down if s/he changes into a lower gear and pedals at a higher cadence?

If this is true, what is the physiological explanation for this?

Just saying that the legs are working harder and the heart is working less harder doesn’t seem to make sense because if the power output is the same, then surely the legs are working as hard at either cadence. 😕

The opposite will happen. HR will increase, as efficiency will also decrease

JungleBiker said:

Is it true that, all other things being equal (speed, power output, terrain, wind, etc), a cyclists heart rate will slow down if s/he changes into a lower gear and pedals at a higher cadence?

I think what you meant to say was "a cyclists heart rate will slow down if s/he changes into a higher gear (smaller cog on the rear) and pedals at a lower cadence."

All other variables being held constant, when one pedals at a higher cadence their corresponding HR will increase. People tend to vary on how efficient they are at different cadences. My most efficient cadence is around 70 RPM's, however, I produce more power at a higher cadence. At 100 RPM's though, I'm just spinning the pedals and not going as fast as that is pretty much an exercise in futility in my case.

Doctor Morbius said:

I think what you meant to say was "a cyclists heart rate will slow down if s/he changes into a higher gear (smaller cog on the rear) and pedals at a lower cadence."

Yes, you are right, that's what I meant to say! :o

So heart rate does go up, but efficiency goes down. But I am just curious to know why that should be, if the amount of work being done is the same? Perhaps it has something to do with the rate of blood flow and oxygen supply. Or perhaps it is similar to a car running along at a constant speed which if run in a lower gear will probably burn more fuel than if running in a higher gear? (I hope I got my highs and lows right this time! 😄 )

Ah well, I guess it doesn't make much difference what the reason is.

Thanks anyway.

there is a trade off. remember that muscles take longer to recover than the cardiovascular system. this is very important for stage racing etc. it's one of the reasons carmichael has lance use a high cadence.

Yup. Just what VelomanCT stated. There is a trade off in which system you tax. Spin faster and tax your cardio system. Mash the pedals and tax your leg muscles. The cardio system recovers much faster than skeletal muscles, which makes it a very good strategy in a stage race.