I haven't run as much as I was hoping to during the summer, for various reasons. One reason is that my pace seriously increased after my new personal record on 10 km. It's caused a lot more exertion, the result of which has been that I've been on the verge of injuries most of the time.
For example: last Monday I ran 14 km in one hour. My left knee was sore for a full day afterwards. I must have pretty good oxygen uptake, because it doesn't really feel like I'm running very fast. But, objectively, that's pretty fast for a casual runner. 4:20 per km.
A big challenge for me is to keep my pace down. Pushing hard comes naturally, for some reason. It's what my legs do if I don't focus. Today I made some progress: I ran 11 km in 57 minutes. That's "only" 5:20 per km. Still pretty fast for a casual runner, but at least slower than usual!
And my legs are a little tired, but nothing hurts and nothing is sore. That's a win!
-- CC0 Björn Wärmedal