Whether on my days off or on from sprinting workouts, I do my best to stretch no matter what but for the most part I make stretching either part of the workout or way earlier or later in the day because I do recover quickly and even cold I'm pretty well limber. I don't necessarily believe in the warm-up stretching or the cool down method because I feel great already before and after my workouts and as far from my experience I haven't had any severe injuries.
As I get older sure stretching will be more of a priority but not the type of stretching mainstream "trainers" have you do, the toe touches and the aerobic style of stretching; my thing is to do what combat athletes do or Animal Flow/Playful Movement where you develop flexibility, mobility & dynamic/static stretching that isn't passive or typical. This style works for me especially for my lower legs because as you know I have a rod and altogether 10 pins in my legs holding my bones together. I do pull a muscle from time to time but never to the point where I can't walk or the arms are completely immobile.
Most stretching systems don't really care about the tendons and the ligaments, mostly just the muscles and that's where a lot of injuries are becoming more reoccurring than ever. The true power is in the joints so when they become strong you become stronger. Muscles are needed but everything is connected and when you neglect one thing, that other side becomes more stressed and becomes overused. When I sprint, I do my best to get the workout done as best and fast as possible while recovering well and fresh. When you combine flowing movement with key point stretching and holding deep squats you're developing crucial elements that stick within your body and as long as you maintain it, you can live a full quality life of pain-free and powerful mobility.
One of my favorite forms of mobility is the Regeneration Exercises from Mike Fitch's Course Bodyweight Athlete where you can do simple movements that hit muscles and joints in a specific way that can practiced practically anywhere and puts you into a state of mind where functionality is at a high level of precise mobility and flexibility that transcends many other forms. Don't believe me? Grab the course for yourself and develop your entire structure through powerful movements, crisp flows, regenerate your body on off days and hone amazing skills that take your training into the stratosphere. Although i'm merely mentioning this for sprints, this type of training can be used for any other training. Make it a point to not just stretch to get better but develop greater quality of life in your body that can help you do amazing things no matter what your age.