Chinese 12-year-old Yu Zidi makes history by becoming the youngest medallist in World Aquatics Championship history.

German official questions why rules changed to allow 12-year-old to swim at World Aquatics Championships, says children not mentally ready.

SINGAPORE: Swimming’s governing body said Wednesday it will “have a look” at its entry rules after Yu Zidi’s participation at the world championships at the age of 12. The Chinese…