The older I get, the more I notice that sitting for long periods of time makes me achy and sore. I'm considering getting this book. Mind you, I definitely do not need another fitness/health book. I just happened to be impressed by an article about it. I think it was this article. I think she mentioned how for every 20 minutes of sitting, we should get up and stretch for a while. I need to start doing that more regularly. I used to be very vigilant about that.
Yes, this. Yoga, swimming, and gentle exercise helps me a lot.