regarding the lower body what's bad about sitting is that it overstretches your gluts and tightens your hamstrings and amongst other things as well. Its not a black and white thing where sitting = bad for flexibility, it doesn't really work like that. I've herd a source say every 30 mins u should get up and walk around or stretch, but its not really realistic in any job or ect.
Be careful when u say things like "i ve herd that" because if u don't know for sure someone might believe u and pass on the information like its 100% true, u might be wrong. Its not the end of the world but u know what i mean.
I even hear eddie bravo say to stretch your hamstrings if u have back pain. If everyone would listen to that advice some people would actually make it much worse for them and could actually cause some permanent damage in some cases. Im sure eddie is just trying to help people but u get what i mean.

Originally Posted by
Jayamilne
Another thing to consider is what you are doing the rest of the time when you are not rolling? Do you sit a lot, especially for long periods of time? Sitting really can negatively impact your flexibility, even if you stretch every day. I've read that you should not sit for longer than 20 mins at one point if possible and be very aware of your posture. I have very tight hips and lower back and after a long day as a desk jockey, it takes me quite a while to un-wind.