I am a runner, on and off depending on injuries and life, for the last 15 years. I fixed my running form best I could, but never got the hang of high cadence. Everyone says that around 180 smp is best, use a Metronom to get used to the speed of the steps. But it always felt forced to me, like extra work with little benefit. So I did my runs at 160 spm. Last Weekend I did 11 km and on the final stretch I stopped the music and listened to my body. I played with the lean of my straight torso and when I shifted my lean forward, my steps got smaller and faster, while I went the same speed.
It was that simple. I checked the t watch and I was spot on. It was not too hard, it felt good, like a balance of fall and catch on every small step. I never got it before, but I think now I do.
I'm mostly at 160, a bit higher if I go faster, and lower if slower. I think aside from speed, leg length is a decisive variable. I am tall and have long legs, so I don't expect I'll ever average above 170.
As for the magical 180, my own take is that the idea has persisted because it’s a good aspirational goal for many runners. Lots of runners overstride, crashing down on their heels and putting excessive force on their joints. Telling them to increase their cadence by, say, 5 percent results in shorter, smoother strides, and reduces loads on the knee and hip. But there’s a very big difference between saying “Some runners might benefit from increasing their cadence” and “All runners, regardless of what speed they’re running at, should take at least 180 steps per minute.”