The write-up below the video talks about trying to keep the foot behind the knee as it comes forward in order to maintain the correct shin angle and avoid overstriding. I've done quite a bit of work on shortening my stride in the relatively recent past in order to fix this same problem, but addressing shin angle is a novel approach for me. It worked quite a bit better than just trying to speed up my turnover ever has.
It all comes back to swimming, really. When you swim, you want to reach out with every stroke and glide. Good swimming form is about pulling through and gliding long, regardless of which stroke you're using. The glide is probably a little more noticeable in butterfly or breaststroke, but it's definitely there in freestyle. A good freestyle stroke is a long freestyle stroke.
This is decidedly not what you're trying to do when you run. You don't want to reach out. That's the whole point with this shin angle thing. Keeping proper shin angle forced me to keep a short stride, diametrically opposite to my natural inclination. I couldn't reach out; I had to speed up turnover. This created ludicrously short, almost choppy strides. With that, I picked up the "rolling" motion that some runners describe, but that I've always struggled to feel. My stride became ridiculously compact, not just in my feet but in my whole body. Usually I'm all over the place, with way too much motion up-and-down and side-to-side. Usually my arm swing is a little too dramatic for good form. But fixing my shin angle changed that. Everything was shortened, leaving no time to "reach" in any extra direction.
I felt the difference immediately.
I could feel that I was running more correctly, but I was definitely not running any easier. If anything, the push to hold that quick turnover forced me to run a little faster than normal, and that made me work a little harder than I might've preferred. My first run, I went 3.45 miles at an average 9:05/mile pace, but I was wildly uneven. I was much faster downhill and much slower uphill. Overall, though, running is running. My pace and distance took about as much effort as I might've expected with my more typical, more instinctive stride.
The real difference came afterward. I was much, much less sore than normal. Usually running makes me feel like I've taken a low-scale beating. My quads and hamstrings are always stiff and borderline useless for about the next 24 hours, and sometimes my knees ache as well. More than anything, that's why I don't run particularly well. It's been hard for me to train as a runner multiple days in a row. I get too beat up.
But I felt great after that first run, which was weird, especially because I felt like I'd had to push a little to hold that quick stride. Certainly, the stride took some mental effort. It wasn't "natural"; it was a fix to what comes natural. After Tuesday's run, though, I wasn't sore at all, to the point where I then ran again on Wednesday.
I made an effort Wednesday to slow down. Wound up going something like 3.2 miles at about 9:30/mile pace. I made an effort to keep a more compact stride, but it's definitely difficult to really maintain that shin angle correctly without running some bonkers, super-high-turnover pace.
I've got to work on that.
I'm a little sore today, after two runs in a row, but I'm also excited. I feel like I'm improving. I hope to run again on Sunday and see if I can build on what I've learned.