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Cadence data redux

September 18th, 2011

Last week I posted some data about my running cadence at difference running paces, which sparked plenty of interesting discussion here and at several other sites including Pete Larson’s Runblogger, Amby Burfoot’s Peak Performance and Brian Martin’s Running Technique Tips. All of those folks also sent me some data on their own cadence-vs-pace curves, so I just wanted to share the updated graph:

Without rehashing the whole discussion from last week, the key point I take away from this is that cadence changes as a function of pace (and in a fairly predictable manner, at that). The runners shown here vary dramatically in age, morphology, speed, running shoe preference, running style and probably many other parameters — and as a consequence, at any given pace they have different cadences.

Some might argue that, if all of us took a course to learn the “perfect” form, our cadences would converge toward similar values. That’s an interesting debate — but not the one I’m focused on here. Because even if we did all have the same cadence at 5:00/km, this data suggests very strongly to me that we’d have a faster cadence at 4:30/km, and an even faster cadence at 4:00/km. The moral: any discussion of cadence, whether of an individual or a group, is meaningless without implicitly or explicitly considering pace.

  1. Ian
    September 18th, 2011 at 12:10 | #1

    “Some might argue that, if all of us took a course to learn the โ€œperfectโ€ form, our cadences would converge toward similar values.”

    This ignores another important variable – dimensions of the runner in question. With this ‘perfect’ form, would people really argue that a runner like Mathew Centrowitz would have the same cadence as a runner like Asbel Kiprop?

    The latter could probably step over the former without even realizing it, yet they finished mere meters apart at the World Championships 1500m.

  2. Kirk
    September 18th, 2011 at 14:15 | #2

    Exactly the point I was going to make, Ian. I seriously doubt that “perfect” cadence for me (at 6′ 5″/196 cm) would be the same as triathlete Mirinda Carfrae, who is only 5’3″/160 cm, even at the same pace. It’s incredibly annoying to see non-stop referenced to the “ideal” cadence of 90/min without consideration to any other factors. If I hit that, I’d look like Wile E. Coyote!

  3. Richard Ayotte
    September 18th, 2011 at 18:51 | #3

    @Kirk Usain Bolt was doing about 257 steps per minute when he set the 100m record and is about your height ๐Ÿ˜‰

    I’m sure there is a perfect cadence for a given body, distance and speed. What are the physiological factors? Leg length, leg power to body weight ratio, flexibility and VO2Max? Can we determine cadence for a sustained speed over a distance knowing these other factors?

    I don’t think that it’s a good idea to consciously change your cadence because your cadence is perfect already for your body, whatever it is.

    If 180 is identified as the perfect cadence for a given speed and distance then instead of trying to consciously change your cadence, you need to change the factors that affect your cadence.

  4. alex
    September 19th, 2011 at 01:08 | #4

    My favourite example of tall vs. short was Geb and Tergat. Here’s a great slow-mo clip from the 2000 Olympics, showing the last lap of the epic 10,000: http://www.youtube.com/watch?v=5D56ZAvcxN0

    They’re going exactly the same pace (until the final stride!), but they clearly have different cadence. No bonus points for guessing whether 5’3″ or 6’0″ has the longer stride! As they say, when it comes to running stride, if one of these guys is wrong, I don’t wanna be right!

  5. September 19th, 2011 at 01:18 | #5

    I’m still trying to figure out why my cadence is so high! I’d hypothesize that maybe it’s related to my footwear preferences, but I have no idea if my cadence has actually changed over the years. Interestingly, studies have suggested that body weight, height, and leg length are not strong predictors of stride length, go figure…

  6. alex
    September 19th, 2011 at 02:01 | #6

    @Pete Larson
    There’s only one way to find out, Pete: I hereby sentence you to one year of running in Brooks Beasts! ๐Ÿ™‚

    I’m still skeptical about leg length not being a factor. I can definitely believe that, among the many factors that contribute to stride length, its effects might seem minor or even be washed out (i.e. comparing a heterogeneous group of runners). But it simply seems “unphysical” (the word we used to use in physics when the apparent solution to a problem produced a negative energy or some other obvious error!) to think that, in a group of otherwise homogeneous runners, leg length wouldn’t affect stride length. But again, I don’t have data, just stubborn preconceived biases!

    As for the mystery of your stride, it’s definitely interesting. I agree that the most likely hypothesis is that your footwear choice is key — after all, higher cadence is one of the benefits going minimalist is supposed to encourage. But who know what other factors may contribute to pushing you up a few beats?

  7. AG
    September 19th, 2011 at 16:39 | #7

    Can you normalize the data in the plot to leg length?

  8. Andrew Chow
    April 3rd, 2012 at 01:40 | #8

    Just stumbled into this chart on the internet. Different folks have similar frequency/speed curves, but so what. The most efficient way to run is to keep the highest step count possible at all times and let stride length vary to dictate speed. It can be proved by physics.

    For airborne strides, what is stated minimizes hang time at all speeds. For grounded strides, what is stated minimizes leg angle at all speeds, thus a lower cosine effect on leg force.

    There is an energy cost to maintain a high cadence, in just the effort to swing arms and legs to 180, 200, or more steps per minute. The energy savings from a higher cadence from the legs working against gravity (the effective shortest strides from what was stated above) far exceeds the energy expenditure to get up to the faster rhythm. The natural frequencies of arm and leg swings are more or less in the range of 130 to 140 steps per minute, and it takes work to move arms and legs quicker than natural frequencies. For the 250 plus step count by Boldt and Felix, they can pump their arms (and legs) that fast on short term, and 180 on long distances just happens to be what typical runners can sustain long term. With the field already beaten, the late Wanjiru ran 190+ at my count as he approached Birdsnest.

    As long as information is out there to vary cadence with speed, runners are just not going to know how to optimized. At the recent Olympic Trials, it was sad to see Davila and Flanagan both ran with water bottles in hand, which increased arm moment of inertia and thus reduced natural pendulum frequency of arm swing. Slower arms or greater effort to swing arms (and thus to keep leg cadence) is not going to help them in London.

  9. alex
    April 3rd, 2012 at 02:38 | #9

    @Andrew: “It can be proved by physics.”

    How?

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