Force & cadence

Answer: 3.

I'm almost identical in my preferred cadences, right down to the actual numbers. I even do it climbing. When I want to increase power, I always go to cadence first. When I look at my PM and my power is a little lower than I want, I always pick up cadence first and only gear up when I feel I've "topped out" in my cadence comfort zone. There's only one difference between us. I don't give it the slightest thought. I just pick a cadence that feels "right."

I've been considering this subject for a while now, mainly since my last day out in the hills. As I have mentioned in a precious thread 'Using hills for VO2max....', I have noticed that on the hills where I am hitting VO2max power, the fact that my cadence is so low (< 60rpm), my HR is not getting the workout it should be getting, compared with when I do specific VO2max intervals on a turbo trainer (cadence 90rpm) when my HR is hitting much higher stress levels.

These observations have been bought about by using the Cycling Peaks software using Andy Coggan's power levels based on my FTP. I'm not for one moment saying the levels are wrong but cadence does seem to play a part in contrasting cadence/HR levels at a constant power.

I find myself apprehensive about mentioning HR too much, but is it not to some degree a measure of the physiological adaptations I'm trying to make?

AndROOb said:

I've been considering this subject for a while now, mainly since my last day out in the hills. As I have mentioned in a precious thread 'Using hills for VO2max....', I have noticed that on the hills where I am hitting VO2max power, the fact that my cadence is so low (< 60rpm), my HR is not getting the workout it should be getting, compared with when I do specific VO2max intervals on a turbo trainer (cadence 90rpm) when my HR is hitting much higher stress levels.

These observations have been bought about by using the Cycling Peaks software using Andy Coggan's power levels based on my FTP. I'm not for one moment saying the levels are wrong but cadence does seem to play a part in contrasting cadence/HR levels at a constant power.

I find myself apprehensive about mentioning HR too much, but is it not to some degree a measure of the physiological adaptations I'm trying to make?

I think this same question can be asked throughout the power/duration curve. We can always make a given power with either (more) pedal force or (higher) cadence. And, the more pedal force option always (for me at least) results in a lower HR. Personally, I favor the higher end of the cadence spectrum at all power levels, but I am not choosing that option for a greater adaptation benefit, but rather simply because I feel more comfortable at that end. If I am building more capacity in some way, great, but I doubt it.

This good discussion gets right to the heart of gear selection. I've also found that I tend to select cadence by "whatever it takes" to produce the required power output, not by picking some "optimum" magic number.

The simple analogy I think of is my manual shift turbo car. I can climb the hill leading to my house, a 10-14% grade, either in 4th gear at 2000 rpm, or 3rd gear at 2500. Normally will downshift and climb in 3rd gear, since it places lower loads on the motor. In 4th, I have to open the throttle a bit more, and generate some boost. 4th gear puts more force on the pistons and crank, and more heat into the cylinders, but is likely to be slightly more efficient overall in terms of fuel use.

On my bike, I can leave it on the big ring and hit the turbo boost too. But things always seem to overheat and sieze pretty quickly, requiring an extended cool-down until I can go again. 🙂

AndROOb said:

I have noticed that on the hills where I am hitting VO2max power, the fact that my cadence is so low (< 60rpm), my HR is not getting the workout it should be getting, compared with when I do specific VO2max intervals on a turbo trainer (cadence 90rpm) when my HR is hitting much higher stress levels.

I believe the stresses take place on a metabolic level in the muscle cells, and that the heart doesn't need a workout by being forced to beat more quickly.

Regardless of cadence, if the same energy is being produced within the muscles then the metabolic stress will be the same.

frenchyge said:

Regardless of cadence, if the same energy is being produced within the muscles then the metabolic stress will be the same.

Well, in a band around one's own natural cadence yes, but at the extremes, no. The only way your statement would be true would be if people were equally efficient at all cadences, which is certainly not true.

Luckily it's pretty easy to tell when you are pedaling at a cadence outside your own particular 'efficiency zone'. Our brains are remarkably good at letting us know when something just isn't right.

Scott

scotmart said:

Luckily it's pretty easy to tell when you are pedaling at a cadence outside your own particular 'efficiency zone'. Our brains are remarkably good at letting us know when something just isn't right.

I agree with this statement. Unfortunately, I think this is where HRMs can lead cyclists to sub-optimal cadences. At virtually any power, a lower cadence will result in a lower HR, which many associate with being a good thing. This leads them to ride at lower cadences than I think they would if they rode with a power meter and ignored their HR.