Ime, I used to run occasionally and never warmed up, but once I started running more seriously (5-6x a week, interval/long runs, ~20 miles a week) injuries popp

Ime, I used to run occasionally and never warmed up, but once I started running more seriously (5-6x a week, interval/long runs, ~20 miles a week) injuries popped up right and left (knees, hamstring, shin splints). Warming up improves range of motion and flexibility, and I run with much better form. Cooling down I dont do as much, but I do focus in muscles that feel tight. Tight muscles tend to have poor flexibility and can lead to injury and poor performance.