Update 2018-12-11: I've stopped having any days where I run going for maximum speed trying to beat my best time, because I found I was pushing myself too hard and hurting my knees.
Update 2018-12-11
Update 2018-12-11: I've stopped having any days where I run going for maximum speed trying to beat my best time, because I found I was pushing myself too hard and hurting my knees.