The role of cadence in performance

Tom Butcher

RChung wrote:

Tom Butcher wrote:

Alex_Simmons/RST wrote:

As I said before, that's because we can't control leg speed independently of the forces being applied.

Cadence is just easier to measure (and hence much more commonly measured) than are pedal forces, so we tend to think of it as independently important, when really it's (per se) a red herring.

So in other words you'd argue that you can jump equally effectively in a big gear with a lower cadence - or am I misinterpreting you ?

If you're jumping you're choosing to change your power. You choose your power then select a gear (if you're not on a fixed gear) that allows you to find the combination of pedal speed and pedal force that allow you to attain that power. You don't choose the pedal speed or pedal force independently of each other--instead, you choose them jointly subject to the condition of increased power. Cadence, by itself (just as pedal force, by itself), is a red herring. Pedal speed and pedal force are outcomes of choosing a particular level of power. Since they're dependent variables (dependent to the choice of level of power) exogenously changing pedal speed (or pedal force) isn't going to change steady-state power since you'll just be changing pedal force (or pedal speed) in the other direction.

Choosing implies a decision - you decide what effort you are putting in alongside choosing how fast you spin your legs and what gear you want to be in. Of course they are interlinked and you don't choose them independently of each other but one is not simply an outcome of the other.

That isn't to say that cadence or leg speed is or isn't relevant but you haven't actually contributed to that discussion either way.

Alex_Simmons/RST

Tom Butcher wrote:

RChung wrote:

...

but you haven't actually contributed to that discussion either way.

Hmmm.

Alex_Simmons/RST

As to the question of jumps/hard accelerations, maximal/peak power typically coincides with cadences in the 120-140rpm range, although I have set peak power PBs during a standing start (at much lower cadences) as well as during a rolling sprint.

RChung

Tom Butcher wrote:

That isn't to say that cadence or leg speed is or isn't relevant but you haven't actually contributed to that discussion either way.

Ah.

Tom Butcher

well argued sir

RChung

Tom Butcher wrote:

well argued sir

Thanks. I worried that it might be a tad subtle but, after all, it's Christmas (at least, where I am) and I had to choose my level of effort. The length of the post and amount of force used in the post depends on that.

fish156

RChung wrote:

..... I had to choose my level of effort. The length of the post and amount of force used in the post depends on that.

I'd call that chosing your moment.

RChung

fish156 wrote:

I'd call that chosing your moment.

Very good. There's also frequency of posting.

fish156

RChung wrote:

fish156 wrote:

I'd call that chosing your moment.

Very good. There's also frequency of posting.

I don't know watt you're implying there?

RChung

I'm listening. Keep torquing.

fish156

Good grief, give me strengh. Although Alex would say I have the power to reply.

Tom Butcher

Great stuff...but still some further explanation as to why we can "choose" power but we can't "choose" how fast we move our legs would be nice. Of course they are interconnected but it's not immediately obvious why one is necessarily seen as a dependent variable and one independent.

RChung

Tom Butcher wrote:

Great stuff...but still some further explanation as to why we can "choose" power but we can't "choose" how fast we move our legs would be nice. Of course they are interconnected but it's not immediately obvious why one is necessarily seen as a dependent variable and one independent.

Because we can choose power (up until we hit our maximum) and that choice puts constraints on cadence and pedal force (or crank torque). You can see from the power-speed equation that it's power that makes us go, not cadence (in isolation) or crank torque (in isolation). Even for the same level of power, cadence and crank torque will vary according to crank inertial load.

http://anonymous.coward.free.fr/wattage ... nents.html

fish156

OK, so let's put this another way.

If I'm going to do some specific intervals, is there any merit in targetting a cadence higher than that which I'd do if I wasn't considering the cadence?

RChung

fish156 wrote:

If I'm going to do some specific intervals, is there any merit in targetting a cadence higher than that which I'd do if I wasn't considering the cadence?

Depends on what your training goal for the intervals is. If you're doing FTP intervals on a geared bike on the open road, probably not much. That's a case where you should just focus on power and use your gears so that you can do that comfortably and sustainably. If your FTP increases your pedal speed and pedal force will naturally increase -- conversely, there's no evidence that holding your power constant but gearing down to increase your cadence (and thus, decreasing crank torque) will raise your power. FTP is the tide that lifts all boats.

fish156

RChung wrote:

Depends on what your training goal for the intervals is.

Many & varied. Recently I've been tending to use a smorgasbord of sessions from Hunter Allen. Some of those specifically target higher than "normal" cadences.

My overall goals are with regard to road-racing, and then breakaway rather than bunch sprint.

Alex_Simmons/RST

RChung wrote:

fish156 wrote:

I'd call that chosing your moment.

Very good. There's also frequency of posting.

That's a red herring.

RChung

Alex_Simmons/RST wrote:

RChung wrote:

fish156 wrote:

I'd call that chosing your moment.

Very good. There's also frequency of posting.

That's a red herring.

Sometimes I'll post just for the halibut.

Alex_Simmons/RST

I know this thread is dead but I can't help but carrion.

RChung

Alex_Simmons/RST wrote:

I know this thread is dead but I can't help but carrion.

Carrion? You saying it's better read than dead?

Trev The Rev

RChung wrote:

Tom Butcher wrote:

Alex_Simmons/RST wrote:

As I said before, that's because we can't control leg speed independently of the forces being applied.

Cadence is just easier to measure (and hence much more commonly measured) than are pedal forces, so we tend to think of it as independently important, when really it's (per se) a red herring.

So in other words you'd argue that you can jump equally effectively in a big gear with a lower cadence - or am I misinterpreting you ?

If you're jumping you're choosing to change your power. You choose your power then select a gear (if you're not on a fixed gear) that allows you to find the combination of pedal speed and pedal force that allow you to attain that power. You don't choose the pedal speed or pedal force independently of each other--instead, you choose them jointly subject to the condition of increased power. Cadence, by itself (just as pedal force, by itself), is a red herring. Pedal speed and pedal force are outcomes of choosing a particular level of power. Since they're dependent variables (dependent to the choice of level of power) exogenously changing pedal speed (or pedal force) isn't going to change steady-state power since you'll just be changing pedal force (or pedal speed) in the other direction.

Experiments conducted by Russian sports scientists in the early 1950s proved beyond reasonable doubt that red herrings increase a cyclist's power. You still need to press harder and faster on the pedals.

RChung

Trev The Rev wrote:

Experiments conducted by Russian sports scientists in the early 1950s proved beyond reasonable doubt that red herrings increase a cyclist's power.

Solely?

Herbsman

RChung wrote:

Trev The Rev wrote:

Experiments conducted by Russian sports scientists in the early 1950s proved beyond reasonable doubt that red herrings increase a cyclist's power.

Solely?

Oh for goodness' hake. :roll:

Herbsman

Trev The Rev wrote:

Experiments conducted by Russian sports scientists in the early 1950s proved beyond reasonable doubt that red herrings increase a cyclist's power. You still need to press harder and faster on the pedals.

Were these experiments carried out on the road or on turbot trainers?

RChung

Herbsman wrote:

Trev The Rev wrote:

Experiments conducted by Russian sports scientists in the early 1950s proved beyond reasonable doubt that red herrings increase a cyclist's power. You still need to press harder and faster on the pedals.

Were these experiments carried out on the road or on turbot trainers?

The results were probably a fluke.

Herbsman

RChung wrote:

The results were probably a fluke.

Looks like they used the wrong type of power meter. Maybe they need to review their app-roach

Alex_Simmons/RST

Are we back breaming with confidence? Or about to flounder?

cycleclinic

Spinning helps impove my cardiovaslusar fitness so cadance is important in that respect. tjhat why I spin. I notived this alot as I went out for the club ride on my single speed. My heart rate felt higer than it does normally on my geared bike. In fact I had to spin so much that after a about 45 miles I could no longer keep up with the 17 mph average that we were doing and droped back wioth few other riders. On ageared bike I could have lowered my cadance and I would have kept up. So what ever the red hearring maybe, I need to spin more.

Trev The Rev

RChung wrote:

Tom Butcher wrote:

Great stuff...but still some further explanation as to why we can "choose" power but we can't "choose" how fast we move our legs would be nice. Of course they are interconnected but it's not immediately obvious why one is necessarily seen as a dependent variable and one independent.

Because we can choose power (up until we hit our maximum) and that choice puts constraints on cadence and pedal force (or crank torque). You can see from the power-speed equation that it's power that makes us go, not cadence (in isolation) or crank torque (in isolation). Even for the same level of power, cadence and crank torque will vary according to crank inertial load.

http://anonymous.coward.free.fr/wattage ... nents.html

Most humans can feel if they are applying more force (pressing harder) to the pedals, they can also feel if they are moving their legs faster. As we can feel it, we can choose to increase or decrease it. The only way to choose power is to translate it into feelings then decide how much harder & faster to press on the pedals.

Cadence or force in isolation do not make us go, but without both you have no power. Power is only the result of force and cadence. If you improve your ability to press the pedals harder more often you increase FTP. You can't put the cart before the horse.

bahzob

There is more to pedalling than cadence/force.

You can pedal badly at a high cadence or a low cadence.

And you can pedal well at a high cadence or a low cadence. (Though it becomes harder at very low c 50rpm and very high 100+rpm if you are putting out around threshold effort).

What marks out a good cadence is that force is applied through the optimum amount of the pedal stroke and all muscles involved are contributing and working in a synchronised complementary manner.

What marks out bad is that force is applied as a massive peak for only a small portion of the stroke. Some muscles will contribute a disproportionate amount of force, some, that could contribute, won't.

Apart from being wasteful (in the sense that some muscles that could be useful are just excess weight) a bad style is more fatiguing because to produce the same power the peak forces each revolution need to be much higher. (Basic physics: if you only apply power through 25% of the stroke the force has be twice that than if you apply it through 50% of the stroke to get the same output power. Indeed it may well have to be more than that since the bike is constantly accelerating/slowing.)

This is aggravated at periods of high effort especially if the effort itself required is irregular. The clearest example of this is a long steep climb.

Someone who can pedal well will treat this as an endurance event with peak force applied rarely if ever going into the red line and coping with sudden changes in pitch by increasing/decreasing revs while keeping force delivery smooth.

Someone who can't will effectively treat this a series on min/max sprint efforts and will hit frequent red lines, especially when sudden change of pitch forces a max effort just to keep the pedals turning.

Guess which gets to the top faster with the least effort/fatigue?