Hello Christian. What is your opinion on strengthening this muscle group in healty, ballanced guy who does many big hip extension movements including direct glute exercises. No sprinting or other intense activity which could involve hip flexors is done.
I use loaded stretching to strengthen the hip flexors (split squat loaded stretch, trying to pull the back leg forward to engage the hip flexor). But I have never really used any specific hip flexor exercises with myself or any athlete or client I have ever trained. It’s probably fine to do it, but I don’t see it as a necessity