To get any meaningful results you need to stretch everyday to achieve a sustained measurable increase in flexibility as you tighten back up as you resume your normal daily activities (sitting, cycling, sleeping). So until you can maintain that flexibility over a few days you really need to do it daily if you want results. A lot of what people perceive as 'weakness' is actually a result of poor flexibility from our lifestyle of sitting as you're literally working against your body to squat or kneel for garden work, it's past someone's functional range of motion. I honestly doubt it's the IT band as that's usually ends up with knee pain but instead the psoas (which is the one that shortens up the most with long hours of sitting) and the glutes. Cycling (or any single repetitive motion activity) is actually terrible for flexibility as it puts you in essentially a sitting position and asks you to do the same low flexibility motion for the next few hours. When I first started cycling I noticed I tightened a up a lot, the muscle got stronger and became harder to stretch out. I still don't have (but I haven't made it a priority) the flexibility I had before I started cycling.