According to many health advocates and recent research, sitting is one of the worst things you can do for your body. I have a job that requires me to sit for 7-10 hours a day and I try to get up and walk for 5-10 minutes every hour. I also implement sitting yoga postures along the way. Every 30 minutes or so I will do a stretch. There are various leg stretch positions you can get in to and keep working at the same time. I also do some rolling, stretching and yoga poses shown in videos to undo the damages of sitting. A standing work desk is a great and I noticed my posture got better and even my legs got stronger. Check out 2 yoga postures I perform in my stretching regiment after a long day of sitting. I also recommend that you work on psoas stretches as well.