What impact does cadence have on power?

Bill Bejin

I am trying to figure out what an "optimal" cadence is as it relates to z3+ work.  Is it better to have a higher cadence (93-96) or lower (87-89)?  I seem to do ok in either after if find the groove.  I have noticed differences in my HR between the two.  

Coach Rich

Posted By William Bejin on 15 Jan 2015 02:44 PM

I am trying to figure out what an "optimal" cadence is as it relates to z3+ work.  Is it better to have a higher cadence (93-96) or lower (87-89)?  I seem to do ok in either after if find the groove.  I have noticed differences in my HR between the two.  

I wouldn't say there's a material difference between those two ranges and I wouldn't worry about HR within those ranges (I'm assuming you have a powermeter?)

In general, higher watts at lower cadences often feel easier, especially if you're climbing. While at the same time, cadence can be deceiving. I'll often see higher watts at higher cadences, though it may feel a bit easier because I'm pressing on the pedals less hard. 

In short, the PM doesn't lie and you'll learn a lot by watching the interaction between power, cadence, riding position, etc. 

Al Truscott

Posted By John Culberson on 17 Jan 2015 09:17 AM


It seems like there is a lot of personal preference to cadence. I have been staring at a TV screen watching legendary climbers breakaway in the French Alps while doing my JOS intervals. Their cadences vary quite-a-bit. When I try to match their cadences, I find that I'm able to maintain my power most easily at a lower cadence. I also know that when I get tired, I ALWAYS fall into that "83ish" zone. I'm not comfortable at a cadence above 92. During a long race, I'm going to vary my cadence without really thinking about it... its hard enough trying to stay at my target power! It is relatively certain that I will be more comfortable and efficient at a cadence that I have used repeatedly in training (it seems as if higher cadences would favor an efficient pedal cycle). By being mindful of my cadence, and training with variable cadences, it is going to add familiarity (and potentially comfort) to my race day bike. The ability to change-up cadence without dropping (or spiking) power is also pretty essential to "nailing" the shifting on a rolling or hilly course. I don't "like" higher cadences, but then again, I don't like 2 x 20' FTP intervals  

+1; Well said.

jertler

I have a related question on this topic - I am new to using my trainer and TrainerRoad. I have a CycleOps PowerBeam Pro and the TraineRoad app is controlling my resistance on the trainer. To to hit the Power targets on my intervals, my cadence is at 100 - this seems way too high, but since trainerroad is controlling the resistance, I'm not sure how I update this. Thoughts/suggestions appreciated! Thanks

Peter Greagg

Jennifer — I don't worry about my cadence at all. See Coach R's comment above.
In fact I do all my OS bike work on a Computer Trainer and the cadence detector hasn't worked for a couple of years.
On my TT bike I use a Joule and am currently on week 16 of Intermediate HIM plan. I note that for FTP intervals my cadence appears to be around 90 and on last Saturday's long ride the total average cadence was 91. Also (as Rich mentions) when quite tired and finding trouble hitting targets late in the day, it is a bit easier to hit them with a higher cadence (around 100).
In other words, just get the work done on your trainer and don't worry about your cadence.
If you are doing any Z3 work, in addition to your FTP intervals, you could try varying your cadence (eg 5 mins @ 80, then 5 mins @ 85 etc).

Sue Chapman

Interesting timing on this post! I'm going round in my mind on this very question right now. Doing the Tour of Sufferlandria. Last year, it wrecked me each and every stage - low cadence, high gears - really mash those pedals which I always thought was the way I "best" rode (not saying most efficient). This year I'm trying an experiment - going for the easy/low gear (sometimes even in the small ring) with higher cadence (which I've had to practice doing and finding the best gear) while hitting the watts. Working with the exact same ftp this year as last. Finishing the rides at higher watts than prescribed but not feeling terrible wrecked at all. So, either this is a better strategy (for me), my ftp is too low so I'm simply not working hard enough (too easy to hit watts at high cadence) -which is what I'm most worried about (tested at the start of the ToS but could have held back), and/or it's too early in the tour to tell (with only 4 stages done).

Then again, I wonder how the cadence to watts fits with trainer road - if there is any correlation - or if it's simply what they think it should be (because it's not customized).

John Henault

Posted By Jennifer Ertler on 18 Jan 2015 05:01 PM


I have a related question on this topic - I am new to using my trainer and TrainerRoad. I have a CycleOps PowerBeam Pro and the TraineRoad app is controlling my resistance on the trainer. To to hit the Power targets on my intervals, my cadence is at 100 - this seems way too high, but since trainerroad is controlling the resistance, I'm not sure how I update this. Thoughts/suggestions appreciated! Thanks

Jennifer -- If TR is controlling your resistance in ERG mode, then as your cadence drops, the resistance should adjust so that the watts stays roughly the same (sometimes it has a short lag and may be off by a few watts).  That's the benefit of ERG mode.  I previously used a PowerBeam Pro before getting the Kickr, and recall the PBP being a little slower to adjust as I changed my cadence, but it did adjust. 

Coach Rich

Sue, your experience highlights the importance of proper gear on race day, I think. That is, while riding at the correct watts is important, doing so at a higher cadence is better than a lower cadence, or at least at a very low cadence.

William Jenks

FWIW, I find that I have a much different natural cadence indoors and out...much higher outdoors (at the same power). When I first had my power meter I worried about this; I have learned not to. Your may or may not have such a difference, but don't be shocked.

Betsy Kantor

Like Sue, I was riding at lower cadence (low 80s) and higher gears. This JOS I have made a concerted effort to get used to/like cadence in the low 90s. I haven't retested yet but don't feel like I am making the FTP gains I was hoping (I tested still not recovered from a flu on 1/6 and feel my FTP is abnormally low). I guess I won't really know until I retest. But, is it normal to feel at higher cadence you aren't able to push as many watts? And, am I correct, that getting used to higher cadence, in an IM, will make the transition to run less painful?

John Schneider

Hey Betsy, I'm in the similar boat as far as having trouble keeping a high cadence and high power. I know Coach R said in past don't worry about cadence during OS, here's my 2 cents for this advice. In the OS you're at zone 4/5 stuff, so I'm slugging away in 80's like you. When you're racing HIM/IM you're at 75%/70% of ftp which is z3. For me it's a lot easier to keep the cadence high 90'ish being near z3. So I don't sweat the 80's cadence during the OS, I just pick whatever gear cadence allows me best to stay in the power range. Also during the OS warmup/cooldown you should have time to keep your cadence up higher than 80's, or when you add z3 time per the OS you can work on your cadence then. Hope that helps you out a bit.

Dino Sarti

Power is just torque (how hard you press the pedal) x angular velocity (how fast you turn the pedal). Increasing either one while decreasing the other at an equal amount will create the same power. Or, increase one without decreasing the other and you make more power. Increase both (harder and faster) and you will make substantially more power.

Based on your body, find a balance that's comfortable and produces the great effect. Also, consider running afterward and see which sets up a better run.

Betsy Kantor

Thanks John S. and Dino for your thoughts.

I have been liking how I feel off the bike at higher cadence. Next FTP test I will see how it goes-if i'm frustrated I can see myself shifting to higher gear, lower cadence in the test, just to get a few extra watts

jimmy augustine

I experimented at IMCoz intentionally riding low 80's instead or trying to be at 90rpm on the bike. I liked the impact on my run. My N=1 experience was that I was mentally fresher to target a run cadence in the low 90's if I rode a lower cadence on the bike.
It also seems to me subjectively that at a given wattage, 80rpm for me means a slightly lower HR than 90rpm. To me, 80rpm means a little more leg and a little less heart. I prefer it and plan to stick there.