I did similar to GB a number of years ago. There was no real science behind it, I’d just read that a higher cadence was likely better, so got a footpod and monitored my cadence on most runs and tried to keep it up there near or above 180. I did actually find some improvement at that point, and it got me to run a bit lighter on my feet for want of a better phrase.
I’ve since stopped focusing on it during runs, but I generally am observing the same as GB with lower cadence on easier training runs, but that it shoots back up in races. Although nothing like to his levels. I seem to have normalised a little below 180 now.
Not to drag a different thread into the mix, but the one thing that has influenced that is the vaporflys, at least in my standalone running races (not so much in tri’s). I’m now much lower cadence over shorter distances than I was before which I attribute to subconsciously trying to leverage the “spring” in those shoes a bit more by lengthening the stride.
At the start of last year, I probably hovered around the 170-174spm range for an easy run.
I’m probably still about that range, with some recent easier runs coming in around 170ish.
At the Big Half last year, I did 182spm ave with a recorded average stride length of 1.46m.
70.3’s came in at 176spm, 1.29m stride length; and 177spm, 1.32m stride length.
This year, in the vaporfly, I did 179spm at the Big Half, 1.50m stride length.
My single 70.3 also in the vaporfly was 177spm, 1.32m stride length.
I’ve also done more other running races this year, so have the following (both in vaporfly):
10k (pb): 176spm, 1.58m
5k (pb): 175spm, 1.65m