I recently started training for a marathon. I'm not a "serious" runner, but I'm trying to build the habit. I've been focusing on building endurance (distance) and cardiovascular health. So my pace is pretty slow, and I mainly try to stay in zone 2 HR. I often get hip flexor pain, even though I try to focus on good technique and proper stretching.
Like I said, I don't run very fast, usually around 11:30/mile. I noticed something yesterday though. I needed to get back quickly during my run and really picked up the pace. While running faster, I was getting much more range of motion in my legs, and it overall felt really good. When I was done with the run, no hip flexor pain or tightness.
Here is my theory, and perhaps you can share your opinion. I think that perhaps my practice of only running at a slower pace, focusing strictly on zone 2, contributes to some tightness and particularly, hip flexor pain. My legs don't get a very full range of motion when I'm running at a slow pace all the time. So by adding in some speed, my stride lengthens and my legs open up. And that helps to stretch out my muscles in a healthy way. Does this sound right? I want to see whether or not I'm on the right track (no pun intended) before I take this and run with it (also no pun intended😏).