After years of explosive growth, triathlon participation is hitting a plateau.

USAT and Ironman’s latest efforts to bring tri to the “tri-curious” masses.

Kona 2016 featured the largest and most diverse athlete field in the event’s history. More than 2,300 racers—two-thirds of them from outside the U.S.—lined up in coveted spots on the pier. From the view in Hawaii, it looked like triathlon is chugging toward its apex, a sport bigger and better than it’s ever been. But after years of explosive growth, triathlon participation is hitting a plateau, and both Ironman and USAT are working hard to maintain an upward trend by bringing the thrill of our sport to more people.

First, a look at the numbers. In the United States, triathlon saw its biggest growth between 2009 and 2010, when participation jumped from an estimated 1.5 to 2.3 million competitors—a 53 percent increase in one year, according to statistics from trade group Sports & Fitness Industry Association. Over the next five years, traditional/on-road races added about 200,000 more racers to reach 2.5 million in 2015, the last year stats were provided.

USAT membership peaked in 2012 at more than 500,000 members, both annual and one-day combined, but dropped about 9 percent last year, while the number of USAT-sanctioned events has held steady since 2012 at about 3,100 a year. “The numbers have been flat going into the last three years,” says USAT president Barry Siff.

Ironman-branded events have followed a similar path, with 40 to 50 percent gains in registrations between 2008 and 2011, according to numbers from the World Triathlon Corporation, Ironman’s parent company. Since then, participation has continued to grow at a more steady—but still incredible—rate of between 10 and 20 percent, with about 85,000 people participating in 41 U.S. Ironman events in 2015. It’s a small but significant fraction of overall traditional/on-road triathlon participation.

Siff chalks up much of the participation plateau to competition from an increasingly diverse endurance sports market. Events like color runs and obstacle course racing provide an active alternative—without the cost of equipment. “Now there are a lot more choices,” he says.

To keep the sport thriving, USAT is focusing on recruiting active people outside triathlon. “We need to increase our marketing emphasis on people who are doing obstacle runs, and [regular] runners,” Siff says. “We need to reach people who are doing Bikram yoga or Pilates.” According to CEO Rob Urbach, USAT will be launching their most ambitious marketing campaign ever, hiring an outside agency in 2017 for the first time in an effort to reach those already-athletic individuals whom he calls “tri-curious.” USAT is also going after younger competitive triathletes.

In 2014, for instance, the NCAA announced the approval of women’s triathlon as an emerging sport, and USAT committed $2.6 million in grant money to help get collegiate programs on their feet. In 2016, USAT aimed even younger by offering its first high school national championship, and began offering $20,000 in grants to eligible high school programs.

Citing the success of that program, Urbach says USAT’s big push in 2017 will be in the youth market. This is essential because USAT’s youth membership was also down in 2015 by more than 15 percent, a decline Urbach attributes to the economic struggle facing youth race directors: It costs more than ever to put on a race, but youth entry fees are typically around $20. “It’s a labor of love for the kids’ events,” he says.

WTC’s strategy closely mirrors that of USAT, going after youth and the relatively underrepresented women’s market. The company has held its wildly popular Ironkids races for kids ages 3 to 15 that piggyback many Ironman and 70.3 events since 1985. And in 2014, WTC joined forces with Life Time Fitness, a company that operates upscale gyms across the U.S., to create Women For Tri. “We want to build women in the sport over time,” says Kyrsten Sinema, a board member for the organization and the first sitting member of Congress to finish an Ironman triathlon. Women for Tri gives grants to tri clubs to help them attract more women, and puts on swim and bike clinics, childcare and social gatherings. “We’d love to see women and men participating at the same level.”

Running achieved that milestone in 2010 when 6.9 out of the 13 million people who participated in a running event that year were women. Chalk the female surge up to a shift toward women’s-only events like Race for the Cure, Nike’s popular races and Disney events that all draw tens of thousands of ladies. Also, almost every U.S. high school has a cross country or track program, which gets young women into the sport early, while high schools are just starting to form triathlon teams.

“When triathlon was in its heyday, it was the next big thing,” says Siff. “Nowadays, there are more choices for the next big thing.” Fortunately, the sport’s leaders have plans in place to appeal to more people than ever before and guide triathlon from this current plateau up to a new peak.