It’s not my intention to write a book on this blog about proper running form. I wouldn’t be the right person to do so and there are already some out there that are quite good. My goal is simply to bring some attention to the importance of running form outside the sometimes cult-like barefoot and minimalist running movements in popular culture. In my mind it’s not about shoes or lack thereof, it’s about running well and having fun doing it.
I’m going to finish this short series of posts with one suggestion that will help many runners, perhaps even most I’ve observed at events of all distances. If these runners simply increased their cadence, the number of foot steps taken in a minute, their form would immediately improve. Don’t go faster, turn over faster. In fact to get started they should run slower, but take more steps to get there.
Back in my first post on this topic, Running Role Models, I described how my own path toward better running started with attempts to minimize vertical motion and stop heel striking. It turns out that these are among the side effects of a slow cadence. Fix the cadence and these problems will likely disappear or at least be drastically reduced.
Why is this? Let’s take each of these issues in turn. To see how cadence affects vertical motion, try this demonstration. Stand upright with good posture in a ready position, feet shoulder width apart. Now take a series of small hops in place. Notice how on each landing, your legs bend to absorb the impact, lowering your center of mass. Then on each hop, you have push back and in fact spring up. On every cycle, your body is moving inches both up and down from your starting position.
Now do the same thing, but very quickly, close to three hops per second. Any difference? In stead of compressing down, you’re probably springing back up completely compressing. The hops get smaller on the up side too.
If you’re still not convinced, take your shoes off. I bet you were wearing shoes that first time, right? Do this again, barefoot on a hard surface. Notice how you land on the balls of your feet, your heels then come down, tap the ground and immediately rebound. At that rapid cadence, the amplitude of your hops is much smaller. You’re springing off of your feet and ankles, not jumping with your legs. “Spring” turns out to be almost the perfect word, but that’s another topic entirely.
The reason this helps reduce heel striking is also pretty simple. If you’re moving your legs that quickly, there just isn’t time for you to swing your leg way out in front to heel strike. There isn’t time for much extra motion, be it pathological or simply inefficient. You probably can strike your heels at three steps per second, but it’s going to be difficult and it won’t be natural.
Much like a car’s engine, humans run most efficiently at a relatively high cycle speed, RPM for the car and foot cadence for the runner. Below that number the cycle is shaky, but as the speed approaches optimal, things smooth out. The three hops (or steps) per second from the hopping experiment turns out to be just about perfect. Humans run best at a cadence of 180.
Bonus: I’d already planned and mostly written this post and look what came up on Running Form Friday, but a post from Danny Abshire on cadence. Check it out!