Thousands of triathletes compete in the 2019 Ironman 70.3 in St. George

Hundreds gathered to cheer on thousands of triathletes Saturday as they tackled the 2019 Ironman 70.3 in St. George.

Athletes said the Ironman 70.3 St. George course is one of the most difficult in the country. With temperatures reaching the mid-80's Saturday.

Top athletes from 35 countries are competing in the Ironman 70.3 North American Pro Championship.

It's the 10th consecutive year St. George has hosted the elite triathlon.

"It's just exciting and it's motivating and it makes you want to go out and be a runner next year," said St. George resident Roni Laub.

Rudolphe "Rudy" Von Berg of Boulder, Colorado was the first to cross the finish line shortly after 10:30 a.m., finishing his race in under four hours.

"[Another teammate] dropped a bottle and had to go back to get it," Von Berg said. "Then right away from there I pushed the pace."

Holly Lawrence from Great Britain became the first female athlete to complete the race, setting a new course record.

"I did swing it by my coach last night, 'Can I go for the course record?'" Lawrence said. "He was like, 'No, you're going to Vietnam. Just play it safe.'"

The race comes just a few days after St. George got the nod to host the 2021 Ironman 70.3 World Championship and announced the return of the full distance Ironman to the city.

St. George officials said the city wouldn't have been chosen for such a colossal event if it weren't for the community and the hundreds of volunteers who work hard to support the triathletes.

Athletes who qualify will head to Nice, France in September for the Ironman 70.3 World Championship.

Registration for next year's St. George Ironman will be open on May 21.

Story provided by our News Partners at ABC 4 News.