not an expert, but I talked to my physical trainer about this. he said sitting all day is not necessarily that bad for you if you sit with a good upright postur

not an expert, but I talked to my physical trainer about this. he said sitting all day is not necessarily that bad for you if you sit with a good upright posture that engages the core. of course, almost no one does this. most people will tend to slouch forward, which has a couple consequences. your shoulders will shrug and round forwards, which will limit your range of motion over time. any stretch that retracts the scapula should help; also if you do any exercise like a row, make sure to focus on really pinching your scapula together. your core muscles will weaken, leaving your spine more vulnerable to injury. "hunched forward" will become your default posture which exacerbates this further. your spine is actually really strong when it is aligned properly, but you need good core strength to do this. doing a "hollow body" pose and your basic plank are good ways to strengthen these muscles (overarching your spine in either direction is a problem).