Before the Olympics even begin, there is always heartbreak. And June may be the hardest month of all.

Caitlin Clark, the ascendant star of women’s basketball, just found out that she won’t be going to Paris. So did Bill May, whose hopes of becoming the first man to compete at the Olympics in the sport of artistic swimming were dashed by the U.S. selection committee.

Over the next few weeks, hundreds more athletes — swimmers and sprinters, divers and tumblers, many of whom have spent years training with the singular goal of representing Team U.S.A. on the planet’s grandest sports stage — will see their dreams of competing at the Paris Olympics pulverized to a fine dust.

That’s because the U.S. trials in sports like swimming, gymnastics and track and field might just be the fiercest crucibles of all, with a ruthless requirement for Olympic berths: Perform well, or you’re staying home.

At the U.S. track and field trials, which are a 10-day smorgasbord of joy and sorrow that starts on Friday in Eugene, Ore., the top three finishers in each event will qualify for Paris — provided those athletes have met the Olympic standard. So, even for someone like Elle St. Pierre, who has the fastest times in the country this year in the women’s 1,500 and 5,000 meters, there are no excuses or do-overs. She knows she must be at her best.

In the 1,500 meters, some of St. Pierre’s toughest competition could come from two of her training partners: Emily Mackay, the bronze medalist in the event at the indoor world championships in March, and Heather MacLean, a former indoor national champion who represented the United States alongside St. Pierre at the Tokyo Olympics.