DD1 and DD2 were never that interested in joining anything, although they did go to gymnastics for a bit. DD3 aged 7 goes to ballet once a week.
A girl in DD3 ballet class does gym, swimming, ballet and brownies. She goes to brownies straight after ballet and doesn't have any tea. She has two girls and they both do lots of clubs. I think that is OTT. Although I have to admit that I'm a bit jealous cos I couldn't afford to pay for my chidren to do so many clubs if they wanted to.