I've always said "you need to be doing at least one thing for your mind and one thing for your body besides school."
I have four kids, and all four are different in what they do. Being active and being athletic are two completely different things. My son (now 24) has always been able to play a pickup game of anything, but mostly road around the neighborhood on his bike or skateboard. Sometimes he'd shoot baskets in the driveway for an hour or so, either alone or with a neighbor/friend/sibling.
One daughter did all the usual dance and gymnastics classes, until she took a swim class and found out she was good at that. She swam competitively until her senior year of high school when she wanted to quit. Now at 21, she takes yoga classes 2 or 3 times a week and swims for fun 2 or 3 times a week.
My 7th grader does ice skating twice a week and one school sport (right now it's tennis). As a little kid, she really just played HARD. I think at 4, she took a dance class. But mostly, she was taken to the playground every day after school, and she PLAYED. Around 4th or 5th grade she started doing ice skating once a week. She's a natural athlete and really just played.
My youngest likes taking lots of classes. Two dance classes, two gymnastics classes, a basketball class, ice skating, swim, etc. She likes being busy. She falls asleep the fastest.