You may really dislike this advice if you’re an avid leg-crosser. It can be a tough one to accept, but ultimately, crossing your legs really isn’t very good for you.
Part of the reason why is simply the act of sitting for hours at a time during the day (which is an entirely separate discussion that I’ll save for another time). But even more so, when we try to isolate the action of sitting with legs crossed, we see that it can create some significant imbalances in the pelvis, which then gets distributed throughout the body.