American champion Sha’Carri Richardson cannot run in the Olympic 100-meter race after testing positive for a chemical found in marijuana.

Athletes spend months, sometimes years, obeying strict diets that are geared toward the goal of making the Olympics.

Ryan Crouser broke a 31-year-old world record in the shot put at U.S. Olympic trials with a heave of 76 feet, 8 1/4 inches (23.37 meters) that also qualified him for the Tokyo Games.

Banned runner Shelby Houlihan saw her chances of competing at the U.S. Olympic trials diminish when the country’s Olympic committee said it would follow all antidoping rules and USA Track and Field received long-awaited official notice of her suspension.

The U.S. Olympic track and field trials take to the starting line this week amid another high-profile doping case.

Shelby Houlihan, the American record holder in the 1,500 and 5,000 meters, posted on social media that she’s been banned for four years following a positive test for what she concluded was a tainted pork burrito.