This is good info. I know some people who stand all day. Here's the article's recommendation:

Try moving every half hour

The good news is that it’s easy to make things better. Just move, both Stamatakis and Ahmadi said. Stroll around your office for a few minutes every half hour or so. Take a break and hurry up and down the nearest stairs. Or slip in some discreet squats while you remain standing in place at your desk. Sit down, stand up, sit down and stand again. “Transitioning frequently from sitting to standing is a good idea,” Stamatakis said, “as there will be some muscular contractions while doing that.”