It seems as though everyone has a hobby, but it can be dangerous to your health. Yes, especially for the people who sew, or create something while sitting. Even for young people sitting for too long at a time can cause blood clots in the legs. You need to move around and take breaks.
I am middle aged and have a lot of arthritis, so when I hurt I don't want to move. But I find that the more exercise I get, the less I hurt. It can seem like a catch 22, but you need to know your own body and remember to get some kind of exercise every 15 minutes or so, even if it's just a break to get a drink or walk outside for a minute.
If you drink a lot of water that will assure that you get a lot of exercise. Especially if your bathroom is at the other end of the house! Also, water is good for your body - no calories or nasty chemicals.