NANTERRE, France — We are taught, rather early in life, that correlation is not causation. But something is keeping the world’s best swimmers from swimming their usual fastest at these Summer Games.

Some swimmers and officials believe the shallow depth of the pool is contributing to slower times. Here’s what the stats and the science say. PARIS — There is an old saying in thoroughbred racing that ...

For many athletes, it is the pinnacle of their career. They have trained hard for years to take part in the Olympic Games. Winning a medal is a childhood dream for most of them—only surpassed by ...