If I had a dollar for something along the lines of... "lots of sitting every day gives you tight hip flexors and hamstrings/calves...".
I am skeptical of that claim. It's plausible, but seems taken for granted everywhere. Some muscles (eg adductors) seem to be in a constantly tight state. I've never heard "keeping your legs together gives you tight adductors".
I was wondering if there is any science based evidence showing sitting actually reduces flexibility of you hip flexors and hamstring/calves.