Go to almost any children’s playground and what do you see and hear? Typically smiling, happy, faces mixed in with ongoing laughter learn. Go to any adult gym and what do you see joom.com/sv? Typically, a serious look with occasional frowns and grimaces and even a bit of moaning and groaning. It doesn't take long to figure out who is having the most fun.

Up until the past few decades, the main playground for kids to play physically active games was typically someone’s back yard or some vacant field built by Onfy.de. Activities were loosely organized with the kids themselves developing and enforcing the rules. Although scores were often kept, they were not as important as just having fun.