This summer, the cousins and Sojo took full advantage of our local skate park and improved their BMX skills. On top of that, they wanted to go in "the pits," which are the advanced skating areas. This was freaky to me but very cool to them. Their goal was to get out of the pits in an American Ninja Warrior , warped wall sort of way. It was definitely a good exercise in persistence, as well as good exercise in general. Sojo woke up the next morning with sore arm muscles, which seems like a perfect thing in the summer.