While not a comprehensive study by any means, it’s bound to generate discussions
“The researchers found that force exerted on the pedals decreased at higher cadences while heart race on average increased by 15 per cent. ”
Well, didn’t we already know that? Less force at higher cadence is the same watts as more force at lower cadence, no? This would mean less muscle fatigue but more cardiovascular fatigue at high cadence right?
POWER = TORQUE x CADENCE
P = 2X[(F x 9.8 x L) x (R x .1047)]
I find this article to be very lacking in details.
“The caveat of the study was the sample size was only nine riders who are described as healthy and active individuals. The study was conducted on a stationary bicycle with riders exercising at a moderate intensity but pedalling at different cadences.”
Seems like a pretty sound study to me…
If you have a power meter that registers PE and TE you can see this in action at low and moderate intensity. Basically, if you’re not pushing as hard, you’re not as efficient at higher rpms. During sprint work or VO2 intervals, different story.
The linked article created far more questions than answers for me. Among many other things, what do they mean by “lower intensity”? I tried finding the original research publication, but failed. This appears to be the cited journal, but its table of contents for January and February issues doesn’t list anything like the referenced study. Can anyone else find it?
As a side note, I’m fairly new to cycling and TR, but spinning at 90-100+ is really natural for me. If I try to stay slower in SS or threshold workout—80 rpm or below—I fry my legs pretty quick. So I’m pretty skeptical of the report to begin with.
One of the editors for Bicycling magazine shared a similar story the other day and it made me wonder. What is a “recreational cyclist”? I have done a few SS workouts where I’ve changed my cadence to see what it did to my heart rate and how my legs felt. At lower cadence(75-80) my HR was lower but fatigue built faster.
As usual with studies, their test conditions were limited, and did not evaluate all scenarios.
I don’t disbelieve their findings under the conditions they tested.
But what about if they tested the same cyclists riding for 3 hours with higher vs lower cadence? Would the low cadence group be more fatigued at the end of 3 hrs? My guess is likely yes.
Gather 9 random people who really like listening to music
Give them a violin and have them play a Paganini Capriccio.
Results are bound to be in line with this study.
Results are horse shit.
I don’t know if you could ever call 9 participants a scientific study.
So I notice that if I pedal at around FTP, (238W) at 85-88rpm, and then increase to 95-97, at the same power, my HR does increase 2-3 beats/m. Or to put it another way, decreasing my cadence does lower my HR… a bit.
However is that efficiency? On a road TT my cadence varies from 82-100, but probably averages around 88-90. When I am doing a pursuit session I am pedalling around 100rpm. On the track sprinting and racing I might hit 120/125. But then again, fixed gear so I have no option. So I practice at different cadences and deliberately do fast spin ups 120-140.
I won’t take anything away from this study. I just watch happens to my body.
I saw a video from GCN I think, talking about the same thing. They did a ‘mini’ study measuring power, oxygen, etc on a fancy piece of equipment. Cadence of 110 and 90 results were nearly identical, but the cadence of 60 used less oxygen and gave the same results.
I have to say that I can relate to this ‘study’ and have data in my TR rides that proves this for me, but I may not be representative of a wider population and in my case it may be due to other limiting factors e.g. lack of muscular endurance.
In the last week I have done Tallac+3, Leconte & Lamarck and in each one I could not hold the power at 85+ rpm in the final intervals. However, I found that dropping the cadence and grinding a harder gear enabled me to complete and exceed target power. So I think for me this holds true.
I had already submitted a question on this so let’s see what Chad has to say.
That’s very interesting, I’ve done Leconte & Lamarck recently as well. I found I’m most comfortable holding 92-94 rpm on Lamarck and then holding the same 92-94 for threshold, but 95-100 for VO2 on Leconte.
Anytime I drop below 90 rpm on threshold or above I immediately feel like I’m bogging down and my power falls way off. I’m on a Cycleops Fluid 2 trainer.
I think it’s a balance between stressing the muscular system (low cadence, lower HR) and stressing the CV system (high cadence, higher HR).
It is possible to sustain significant power for longer by stressing the CV system and sparing the muscles. This extends the duration for which you can work, and has the side benefit of allowing repetition of work.
It is possible to produce similar power using a low cadence, up to the point where the muscles are too fatigued to do the work. If you get to this point, then repeatability suffers.
As a result, the optimal cadence depends on both the duration of the event and also the relative capacities of the muscular and CV systems. In untrained athletes, I would expect the CV system to struggle at high cadences, so the low cadence, low HR process is going to be more efficient. In a trained endurance athlete, the opposite is likely to be true. For shorter events, other factors will come into play. Eg some of the fast TTers around here use relatively low cadences because they find that pushing a big gear allows them to hold their position easier, and they can push that big gear for 20 minutes no problem. If they were doing TTs lasting hours, they might change their approach to match the event.
One of the keys is what are you working on in training.
Prior to TR, my “natural” cadence was around 90. TR’s workout text during sweetspot base has a lot of discussion regarding cadence. This got me working on cadence and raised my natural cadence closer to 100. Previously this felt fast, but now is just normal.
Because I encounter terrain that requires both higher and lower cadences, I now make sure I mix it up on the trainer. Some intervals at higher rates, others at lower.
From a study standpoint, it would be interested to test those that didn’t perform well at a high cadence, but then have them train at higher cadences for 6 months, and then retest. I would be very surprised if their efficiency didn’t significantly improve from the pre- to post- test.
Power = Torque * RPM / whatever constant you need for units
Using this and assuming constant power, as RPM increases you need less torque and therefore less force applied on the pedals. If you keep force constant on the pedals and increase RPM your power will increase. With quick math, keeping 300 watts at 60 RPM is ~60lb of force and at 100 RPM is roughly ~30 lb of force.
So I guess the question comes down to: are humans better at spinning low force or better at grinding at a high force? My inclination is that spinning a low force is much more sustainable for endurance events. I have weightlifted longer than I have cycled so I compare this to squating the bar a lot of times versus squating a lot of weight a few times.
This link didn’t work on my phone but does on computer.
This is a quote someone pulled out.
“The group of participants studied was limited to 9 individuals and rather heterogeneous in terms of age, exercise capacity and cycling expertise. Given the limited sample size considered in this study, we acknowledge that this finding needs confirmation on a larger scale.”
“Power output at Tvent (W) 125 ± 44”
Google tells me Tvent is ventilatory threshold…
So - I completely change my bagging of this study now!
Yes - I wholeheartedly agree if you are spinning 90rpm @ 125watts or even 169watts you are most likely wasting energy in spinning your legs.