Sitting for long periods of time

I've noticed that in the evening when I'm reading, watching a movie...etc. for a couple hours with my legs straight out on a ottoman I often flare once I get up and start moving around.

Has anyone noticed specific positions (ottoman, lazy boy, resting on ground, evelated) that help if you are going to be sitting for a longer period of time? It sometimes seems like the more I can prevent sitting for long period the better it is. thoughts?