These days, sitting isn’t just for relaxing. It is also prevalent for our work, transit, and entertainment time. This can very easily lead to anterior pelvic tilt with tight hamstrings and inactive glutes, tight hip flexors on the front and inactive abs above 'em. To rectify this, hip flexor stretches, time in hip extension and core activation are crucial.
During exercises that are taxing on the core musculature, such as planks and even standing strong in the top of a back squat, try seeing if you can squeeze your glutes maximally. Just by trying to squeeze them together, you will gain some valuable information about your positioning and body’s tendencies. If you can’t squeeze them very tight, you are likely in an overly anteriorly-tilted pelvic position and should remedy it through mobilizations or changes in body position. If you can squeeze them well, it is likely a better position for your pelvis to allow for proper functioning of the glutes, abs and diaphragm. Your low back will be less prone to issues and your abs won’t push your belly out in an unaesthetic manner. Tighter waistline? Happier low back? Why aren’t you trying this right now?!