A couple of follow-ups to the Running Form episode of RRT. Since I’ve already noted my view that one shouldn’t mess with one’s form if it isn’t broken, I thought it useful that there seemed to be agreement on that, even if there was a skewing in the conversation to how-to-change-your-form. (Jeff Kline, who coaches a number of folks I know, and coaches them well, is a smart guy and he conceded the point notwithstanding that he is an advocate that mid-foot striking is the proper approach.) If nothing else, I was hoping on RRT to get clarification on the bromide I read time after time that “heel striking is bad” (readily disproven by a glance on those Boston Marathon videos/photos from Pete Larson). The fact is that all heel-striking is not alike, and the issue is not where the heel strikes but how the foot strikes in relation to the knee. Overstriding is our enemy.

If you look at the Newton stick-man video, it’s the overstriding that is the culprit. That, I thought, was the most important lesson, good form is somewhat idiosyncratic within certain parameters, a major one being not to smash your foot into the ground in a way that sends a shock wave directly into your knee. Which is pretty well where I was on the topic a year ago. Time to move on. I’m not going to change (and when I last tried to I hurt my knee).

As to stride-rate, one of these days I’m going to have to count the number of strides I take when I run (which I’m hoping to do again tomorrow). Jack Daniels came up with the magical “180 strides per minute” figure by counting elites at the Olympics, and it has become the standard.

[StevePete, and Mark have follow-up posts. Steve’s is particularly interesting because he combines it with a solicitation from readers of the ideal shoe, for which he gets load of comments.]

After the episode, there were a number of follow-up emails on that very topic that warrant publication.

Steve Magness:

Also, I wanted to give some concrete numbers to Mark’s question last night.  I’m pretty sure it was Mark who asked me about the East African runner’s stride frequencies.  I wanted to give some concrete numbers.  A runner, and now scientist, who I competed against in college sent me these results a year or so ago.  He took 6 Kenyan’s who ran at UTEP and measured a variety of biomechanical things at various speeds.  These guys were top runners who grew up in Kenya then came over to the US for college to run, so it gives us an interesting glimpse into Kenyan running.  The interesting thing with cadence measurments is that they measured it at a variety of speeds from pretty slow for them to relatively fast.  When looking at the paces keep in mind that these guys are all 14min or faster 5k runners. Just to give you an idea on relative pace, the 7:40  would be a really slow jog. The 6:43= easy distance run pace,  5:58=normal distance run pace   5:22=steady, uptempo, marathon pace kind of effort.  And 4:58 pace is probably right around threshold pace.

Pace per mile       Avg. Cadence

  • 7:40                      175
  • 6:43                      181
  • 5:58                      185
  • 5:22                      191
  • 4:58                      196

Pete Larson:

To follow up on Steve, here are some numbers I calculated from my video – first 9 males to pass mile 17.5 of 2010 Boston Marathon. Very rough since based on timing of only a single stride – they are all probably running in the high 4’s in terms of pace:

1 Cheruiyot 200
2 Merga 212
3 Kebede 186
4 Kigen 209
5 Goumri 191
6 Keflezighi 205
7 runner #7 188
8 runner #8 186
9 Hall 180
9.2 Hall – 2nd step 178

Mark:

Thanks! Indeed, that was my question, and your data demonstrates that the rapid stride frequency of these East Africans – who presumably did most of their early running barefoot – developed and maintain a very rapid cadence. Fascinating in your data is that at their equivalent of a slow jog (7:40 pace) they’re already nearly at 180 spm, and as they approach threshold they’re nearly at 200!

This makes intuitive sense to me, as I didn’t mention it during our phone call last night but owing to Houston horrid heat over the past two months, and my needing to get my speed up I’ve done a lot of work on a treadmill (at two-percent grade so-as to make the pace roughly equivalent to running outdoors.) I similarly find that as I surpass my threshold pace that 180 spm becomes awkward, and thus my PodRunner song choice of 180 bpm becomes a bit of a psychological hindrance as I then have to deviate from that target cadence to ~185 or so – which is my current maximum. Also consistent with the East African data set I find that I cannot maintain 180 spm comfortably when in an easy jogging mode.

So, given this I’ve downloaded *every* PodRunner track to my iPod between 175 – 180, and depending upon my intended pace I dial-in a corresponding musical selection to remind me to maintain my tempo at that level (incidentally, this trick is a bit of a twist on the EvolutionRunning suggestion that runners instead listen to a portable metronome while running (such as this one) but from my perspective a good musical electronic and percussive track is far easier to listen to!

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