Blazing Second-Half Speed Drove Marathon Swimmer Mariah Denigan To An Olympic Spot

While growing up in northern Kentucky, Mariah Denigan’s first swimming lessons were less for sporting reasons than for survival.

“I got into swimming to learn how not to drown,” the native of Walton, Kentucky, said.

As it turned out, she proved to be a natural swimmer — and then some.

Denigan not only passed her basic lessons with flying colors, she became a phenom by age 10 and rode that wave to an eventual spot on the 2024 U.S. Olympic Team in the most grueling event the sport offers.

Now at age 20, the Indiana University junior qualified for the Olympic Games Paris 2024 in the women’s 10-kilometer open water race after finishing sixth at the world championships earlier this month in Doha, Qatar. She joins Katie Grimes and Ivan Puskovitch in having already qualified for the Games as open water swimmers. Most of the U.S. swim team will be named at the 2024 U.S. Olympic Team Trials in June in Indianapolis.

“It was a dream come true,” Denigan said. “When I touched the pad (in Doha), I just wanted to go celebrate with my dad. Every athlete’s goal is to make it to the top of their sport, and the Olympics are the height of swimming. To represent Team USA at that height is an honor.”

Growing up, Denigan was naturally gifted as a swimmer but still dabbled in soccer and basketball through her preteen years. However, as she began rising through the ranks as a swimmer, she dropped the other sports to focus on the pool.

“My friends were confused because they didn’t think swimming was really a sport,” she said.

The results in the water spoke for themselves, however.

A young and strong swimmer, Denigan naturally picked up all the strokes, but she gravitated more and more toward the distance races. Denigan began achieving top times in the nation when she was 9, and that’s when her club coach put open water swimming on her radar.

A top student at Barren Academy of Virtual Expanded Learning, Denigan balanced her online classes with increasingly important competitions, with one of her first big international meets coming at the 2018 Junior Pan Pacific Championships in Fiji, where she won four medals as a 15-year-old. She’s continued her rapid upward trajectory from there.

In 2022, Denigan qualified for her first world championships, and her standing in the 10K race has improved in each of her three trips so far.

At her 2022 debut in Budapest, Hungary, she finished in 15th place, nearly 25 seconds behind the winner. At Fukuoka, Japan, in 2023 she finished in eighth place, nearly 40 seconds behind the winner. This year in Doha, she finished sixth, about four and a half seconds behind the winner and only 0.30 seconds out of fourth place.

In Doha, Denigan was in 27th place at the halfway point in the race before kicking it into another gear.

“I have a lot of back-end speed,” she said. “My last three laps are always faster than the first three. It nearly gives my parents a heart attack because I fall back so far. I need to work on my front-end speed and pick a point sooner when to start that back-end work.”

Indiana swimming coach Ray Looze said Denigan has a “system” that allows her to walk down competitors ahead of her late in the race. He described that system as a combination of a “very advanced aerobic system, mental toughness and a pain tolerance that’s off the charts.”

“I haven’t seen too many people like her in my 33 years of coaching,” Looze said. “That kid has one of the best systems I’ve ever seen.

“Her nervous system and brain can take it, and that’s an amazing quality. I think she flat out trained herself into that. Because of her system she really gets going at the end, where everybody else is falling apart.”

At her three world championships, Denigan has also raced in the mixed 4x1,500 three times, as well as the 5K in 2023 and 2024, with her top 5K finish being 12th in Doha. At the Olympics, marathon swimming includes just a men’s and women’s 10K. Looze said the 1,500-meter — the longest Olympic race in the pool — is “a little too short” for a swimmer like Denigan.

Denigan said that her most intense training consists of swimming between 70,000 and 80,000 yards per week, which equates to about 40-45 miles. Prior to Doha, the swimming staff at Indiana removed all lane ropes from the pool and set up a course with buoys for her to train for the championships.

The marathon race in Paris is scheduled to take in the Seine, which has been in the news over the years for its poor water quality. Paris Olympic organizers have worked to clean up the river so that marathon swimming and other events can be carried out this summer.

Besides competing for a medal in the famous river, Denigan said she’s most excited to have her family along for the journey in Paris.

“My mom and siblings haven’t been on international trip with me since 2018,” she said. “We’re going to take a little European vacation.”

Before Paris, though, she has work to do with the Hoosiers. On Feb. 24, Denigan helped Indiana claim its first Big Ten championship since 2019. Next up are the NCAA championships, set for March 20-24 in Athens, Georgia.