This issue comes up periodically. There is a great article on cyclingnews.com http://www.cyclingnews.com/fitness/?id=strengthstern that addresses this question specifically with references. Of course, I point this out because I believe it supports pretty much everything I have said on this subject 
Frank
An excerpt from that article: “…she testing low cadence work against normal cadence…”
Frankly, Frank, this is where I think some of us have a tough time distinguishing with certainty the benefits of PCs. After my 8-week test, let’s say my 30 minute power trial improves 10%. That would be fantastic! But, are we not comparing low cadence work against normal cadence when comparing the efficacy of PCs?
If my power improves, I will naturally ask: exactly why did it improve? Was it the use of hip flexors? Or was it that fact that nearly all of my quality training over that 8-week period was at low-cadence, high-force overload? After all, virtually everyone with PCs reports using lower cadence and bigger gears during (at least) the first few months. This type of work is new for me, and might result in power improvements on its own, with or without PCs.
So, my question for the gallery is: How can we differentiate the gains some people get from PCs from the gains most people get from a bout of force-endurance (ie, low cadence, big gear) work…like that referred to in the quote above? I suppose that, if someone gets around to a controlled test of PCs, they would need to use three groups. One on PCs, one training normally, and one incorporating low cadence training.
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oh oh julian, here we go again. i think the answer to your very good question lies in experiencial feedback, for good or ill. today i put the the big ring back on my PC bike after a couple mo of using just the small. i rode for 90 min on rollers turning a big gear at a low cadence. the difference in how this technique translates feedback vs just mashing a big gear before i experienced PC’s is too great to ignore. it is the like the difference of xc skiing with a flat ski and full weight transfer vs skiing with no weight transfer. or like swimming easily with body roll and extension vs lying flat and churning. in those activities your question would also be valid - but once you experienced the activity the first way, respectively, you would grasp immediately that it offers something more than the second. honestly, i can trully see your argument from an academic standpoint - i shared it myself. but, like making those first linked turns on a snowboard, some things are really best FELT and not so much neccessarily UNDERSTOOD. PC’s are perhaps one of those things.
ps- i liked the weight training article, too.
Agreed. The PCs force us to do the big gear work with better form and more effectively. But again – is the benefit the big gear work or the hip flexor recruitment?
I must say that we really don’t know. That doesn’t mean the PCs aren’t a great tool. I’m just not sure exactly why they’re a great tool.
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some of the poorer members of this list (or some of the obstinate naysayers) couldn’t try this experiment on their own. Several months of enforced big gear, low cadence, high resistance work and report on their experience. I believe they would see improvement (as I believe low cadence pedaling is inherently more efficient) but I believe they would not see the same gains reported by those using the PC’s, the difference being the hip flexor factor (although I think some of the gains are more than just hip flexors, improved tangential application of force for example).
While this would not be a controlled study, if enough did it we would have enough anecdotal data for people to draw some kind of conclusion.
Frank
ttn
so I want to hear about what happened to your speed after months in the small gear when you went back to the big gear. And what happened to your running speed with all that time in the small gear, are my predictions right on or need massaging?
Frank
increases. Speed will do. If you could ride 25 mph before you can say that was a power of 25 cubed or 15625 pooks. If you now can go 26 mph your power is 26 cubed or 17576 Pooks, or a 12.5%increase in power.
You should be riding at the cadence that gives you the highest speed that you can sustain for the distance you are racing, whatever that is. In the beginning with PC’s it will probably be lower than you did before but with time it will come back up, perhaps to the same cadence or perhaps not.
Frank
(as I believe low cadence pedaling is inherently more efficient)
Frank - I was intrigued by this statment of yours. If this is the case, then why do we hear that the fastest cyclists in the world in big road TT’s are turning it over at 95 RPM? I understand that when Lance Armstrong is racing the 40 - 60 km TT’s that he faces in the big Tours he is consistantly pedaling at 95 - 100 RPM at 50 - 55 km/h.
Just curious.
no data, mr day. i am just on rollers ( no powertap) and it is too nasty outside to do anything real. ’ can’t even count running, really, as it is gonna be low teens and single digits for the next forseeable whenever around here when i run. patience is a virtue - dang good thing, too, as last year it was 37 degrees here on memorial day!
I think the more power one is generating the higher the most efficient cadence. Lance is riding at 90-95 rpm but for the power he is generating that is really a low cadence.
Power is force over a distance in a unit of time. Our power generation is how much force we can put on a pedal and how far the pedal moves in a unit of time. I have done calculations that show the power required to pump the legs up and down during pedaling increase with the cube of the caadence. This is power that is lost to the wheel. So we want to minimize this loss. But, clearly we caan’t go to a cadence of zero (where this loss would be zero) because there is no pedal motion so power output must be zero regardless of how hard we push against the pedals. At low caadences we are limited in how hard we can push against the pedals because we are biological systems and muscles are most efficient at certain forces and contractile speeds. So when it is all put together, lower caadences are better, within reason but higher powers require higher cadences, again within reason.
The optimum cadence for any individual will vary based upon their muscle performance and anatomical considerations and must be determined by trial and error.
Frank
There are a number of studies that make a finer point about cadence. The key “summary article” that I read says that, at lower cadences (at a given power output) cyclists had higher “economy.” Economy is defined there as oxygen consumption.
But, at higher cadences, the same cyclists had better fatigue resistance.
Quote from article (found at http://www.bsn.com/Cycling/articles/cadence.html )
“In summary, laboratory studies indicate that experienced cyclists do not use their most economical or efficient cadences. However, cadences of 90 to 100 rpm are probably beneficial in spite of decreases in economy and efficiency. The explanation proposed here suggests the use of high rpms results in a decrease in average pedal force per revolution and leads to the recruitment of fewer fast-twitch fibers, placing the reliance for muscle power development primarily on the slow-twitch and intermediate fibers. The advantage to the cyclist is there is less likelihood of a rapid accumulation of lactic acid, with the resulting decrease in muscle force production.”
So, you have to decide what your strength is for racing. Endurance or Oxygen uptake. Like Frank said, we all have to find our preferred cadence for racing.
Since I have historically been weak on late-ride endurance, I have gravitated to higher cadences. By forcing me into lower cadence riding, I have some degree of confidence that the PCs will help me train my weakness. I still plan to race on regular cranks at ~90 rpm (I rode at 95-100 last year). The idea being the old saw, “Train your weakness; race your strength.”
I’ve got a 20K TT in February that I can compare against the same one I did exactly a year earlier. Results to follow…
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Quote from article (found at http://www.bsn.com/Cycling/articles/cadence.html )
“In summary, laboratory studies indicate that experienced cyclists do not use their most economical or efficient cadences. However, cadences of 90 to 100 rpm are probably beneficial in spite of decreases in economy and efficiency. The explanation proposed here suggests the use of high rpms results in a decrease in average pedal force per revolution and leads to the recruitment of fewer fast-twitch fibers, placing the reliance for muscle power development primarily on the slow-twitch and intermediate fibers. The advantage to the cyclist is there is less likelihood of a rapid accumulation of lactic acid, with the resulting decrease in muscle force production.”
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Julian,
this article (at least the part you quoted) does not show improved fatique resistance. This is supposition on the part of the author to try to propose a theory as to why cyclists tend to ride an “sub-optimum” economy. There is no evidence (that I am aware of) to support this theory. Further, to propose that higher cadences (higher speeds) recruit less fast twitch muscles seems counter-intuitive.
these theories are trying to explain real world behavior that goes against the experimental “optimum”. However, now we have people training on PowerCranks who increase their speed when they lower their cadence. This conforms better with the experiemental “optimum” but does not conform with the previously propsed theories to explain pre-PC pedaling modes.
I think a better explanation is that racers play follow tthe leader, even when they are learning. so they emulate Lance (or whoever is on top at the time), who is sustaining 350 watts at 95 rpm so they try to ride at 95 rpm even though they can only sustain 180 watts.
you can do that TT twice, one at 90-95 cadence and one at your PC cadence? Maybe unofficially a day or two before or after?
Wellllll…even the “efficient at lower cadences” question has not be put to rest.
Two more quotes:
"*There is no disadvantage to pedaling at high cadences provided that power outputs are greater than 70% of an individual’s maximal aerobic power.(Adapted from Sidossis et al Int I Sports Med,. 13(5), 407-411], 1992 .) " *If you’re really motoring, there is no efficiency penalty for higher cadences.
*"These data suggest that muscular efficiency, as reflected by delta efficiency, may be enhanced at higher cadences. (Adapted from Sidossis et aL rnt J Sports Med, 13(5), 407-411,1992.) " *Your power can go up faster than your usage of energy goes up at higher cadences.
“Efficiency” is defined here as relating work done to energy expended. Delta efficiency relates the rate of change of work done to the rate of change of energy expended (ie, the first derivative).
The assertion that faster cadences enhance fatigue resistance is not an empty hypothesis by the authors. The study by Ahlquist cited makes rather clear that higher cadences reduce the reliance on fast-twitch fibers, leady inexorably to the well-reasoned notion that faster cadences can enhance muscular endurance.
"At any submaximal cycling speed, if we select a high cadence, the glycogen depletion study of Ahlquist et al (1992) suggests that we will minimize the recruitment of fast-twitch fibers. However, we can still supply ATP to the working muscles of the leg using predominantly slow-twitch or intermediate fibers. Since there is less reliance on fasttwitch fibers, there is less likelihood of a large increase in lactic acid in the working muscle."
" How then does the selection of fewer fast-twitch fibers effect the cyclist, and might this be the elusive answer as to why cyclists select high rpms during submaximal cycling? Slow-twitch fibers derive most of the energy necessary for muscular action via oxidative metabolism, in which glucose and fat are broken down and, in the presence of oxygen, large amounts of ATP are formed. ATP, or adenosine triphosphate, is the immediate source of energy for muscle action. In contrast, fast-twitch fibers break down more glucose than can be oxidized to carbon dioxide, which results in the production of lactic acid. While lactic acid can actually be reutilized as an energy source, in large quantities it has been linked to a decrease in muscle force production (see Metzger, 1992, for a thorough review of factors affecting muscle force production). "
The cadence question is not as clear as simple oxygen or energy consumption would first indicate.
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I guess we have to define “high cadence”. this quote by them would suppose there is no difference in efficiency in pedaling at 95 (high cadence for some), 110 (high cadence for many), 120 (high cadence for most), 150 (high cadence for everyone) as long as one is “greater than 70%” maximal aerobic power.
I disagree. I believe there is an optimal cadence for everyone at any given power. To say there is no penalty for increasing above that cadence is illogical. Automobile engines have optimal rpms for torque and power, so do humans.
"I guess we have to define “high cadence”. this quote by them would suppose there is no difference in efficiency in pedaling at 95 (high cadence for some), 110 (high cadence for many), 120 (high cadence for most), 150 (high cadence for everyone) as long as one is “greater than 70%” maximal aerobic power.
I disagree. I believe there is an optimal cadence for everyone at any given power. To say there is no penalty for increasing above that cadence is illogical. Automobile engines have optimal rpms for torque and power, so do humans."
I disagree, too. But the authors only referred to cadences up to 100, so they have not made the assertion you suggest.
Humans aren’t autos. And, while it’s great that you “believe” something, I think we must give at least some weight to the opinions of people that actually test these things for a living. There are a lot of things I “believed” at one time or another in my life that have since been refuted by actual field experience. The Easter Bunny comes to mind…
Just being lighthearted, Frank. No flame intended whatsoever. Just friendly debate. 
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When an author asserts there is no penalty for riding at high cadences presumes to me that they mean an range of cadences.
I believe there is an optimum cadence (which most studies show) and this cadence increases with increasing power (which looking at a variety of studies leads one to conclude). I think the only statement that makes any sense in this regard is “there is no penalty for pedaling at optimum cadence. There is a penalty for pedaling above or below this cadence.” Wouldn’t it be nice for someone to publish a study showing how one can find one’s optimum cadence reliably.
I certainly didn’t feel any warmth from flames from your replies and I hope you don’t feel any from mine. Your questions are logical and reasonable. My beliefs may someday be shown to be wrong. I am a physician. One thing they told us in medical school is: “50% of what we are teaching you will be shown to be wrong in 10 years. Unfortunately, we don’t know which 50%.” So, I am used to it.
Frank
“I’m tired of hearing about the cycling, when is that 1/2 marathon you are supposed to run Julian and what is your latest over/under prediction?”
DOH! I forgot about that! I’ve been so busy having my hip flexors jabbed with hot pokers courtesy of Mr. Day that I dang forgot to run!
A week from Sunday, I SHALL set a new PR in the San Diego half mary by FIFTEEN MINUTES! Last year: 1:57. This year: 1:42.
(or die trying anyway).
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wait with bated breath your results. Good luck!
Frank
Dr. Day, I’m a new PC’er that used to run cadences from 100-110 most of the time. I learned this habit when I used to road race 15 years ago. During road races, I found I had much more “snap” in my legs on the sprint if I spent the majority of the race at a high cadence. My bike fitter told me to drop down to the low 90’s during time trials and I’d be faster. He was right! Of course, my PC cadences are only 70-90 at best, and I still fatigue pretty quick at 90; after all, I’ve only been on PC’s for a few weeks, now.
What I don’t understand is why my knees aren’t hurting me yet with all this lower cadence work…they used to hurt if I did this low cadence stuff, so I tended to only do a smattering of it during the week and saving it for races. I’m concerned I may be setting myself up for some upcoming knee pain.
Currently, I try to keep the cadence at least 75, then, if I have to, I coast a bit to recover before I begin pedalling again. I wonder if this is a good strategy, or if I should try to keep my cadence at 85 or higher…resting as needed.
PS, I’m really pleased with my speed on the flats right now, even when I’m not in my best “aero” position yet. PC’s have also taught me how to stand up on hills more efficiently…I used to never stand, now, it has become an option!