When Carlos Alcaraz is on court for a training session, perhaps working on his newly revamped service motion, he's doing so to buttress a game already good enough to claim four Grand Slam titles.

The men's world No. 1 could face a two-year ban. Here's what to know about the doping proceedings against him so far

Iga Swiatek, a self-described “control freak,” is taking new precautions — including holding on to extra samples of medicine she takes, in case they need to be tested at some point — after a doping case she described as “probably,