The illiotibial band (IT band) is a thick bundle of tissue that runs down the outside of your thigh, from your gluteus maximus to your knee. Its primary purpose is to stabilize the knee. Since it’s not muscle, it doesn’t stretch in the same way muscle does. Even if you’re a conscientious stretcher, your IT bands can stay too tight and cause significant pain. On long rides, I often get some pain near my of gluteus maximus, in the small TFL muscle. The pain is almost always on the right side (I’m right handed) and it’s dull and achy. The general wisdom is that RICE therapy is the best approach: Resting, Icing, Compression, and Elevation. I also find that hip adductor and (especially) abductor weight lifting strengthen the entire area and help me avoid pain altogether. The hip abductor exercises don’t strengthen the IT band — it’s not a muscle — but do strengthen the TFL muscle and that tends to make the IT bands behave properly.