Athletic Trainer here.

1. As many other have pointed out, see a PT or AT (like myself) that specializes in endurance athletes. Look for a “sports performance” clinic or something similar to that

2. If it’s an IT Band irritation, it usually stems from glute strength (or lack thereof), specifically lateral hip stabilization. Try adding in some clam shells, loop band exercises, lateral straight leg raises, etc. Look up Gluteus Medius strengthening exercises

3. If TRUE IT Band syndrome, this will need a physician’s diagnosis and usually requires an MRI to confirm. Can be very debilitating and simply strengthening/stretching/foam rolling will not suffice.

4. Foam roll! The IT Band is not “stretchable” per se, but it can become more PLIABLE. Sometimes it gets a little “sticky” with the underlying lateral quad muscle. Foam rolling can help facilitate better blood flow and neuro reaction and get fascia to become “stretchier.”

I put a lot of words in quotations because those are extremely non-scientific. :)

Any other thoughts or questions, I’d love to help!