When Susie Montoya started training for the Iron Girl Columbia Triathlon 10 years ago, she couldn’t swim – not in a pool, not across a lake and definitely not to complete the 0.62 miles required for the event.

“I have always been terrified of the water,” the 47-year-old Ellicott City resident said. “Always. It’s one of my greatest fears.”

Already a runner, Montoya began taking swim lessons. Then, she bought a bicycle from her neighbor for $25 and joined the Mid Maryland Triathlon Club. Before she knew it, Montoya had become a triathlete.

On Sunday, she will compete in the 34th Columbia Triathlon, and in October, she plans to compete in her first ever Ironman triathlon, swimming 2.4 miles, biking 112 miles and running 26.2 miles.

“It’s totally crazy, but it’s contagious,” Montoya said of the sport. “I fell in love with triathlons because you’re around all these people all the time, and you can’t help but catch that energy.”

Nationwide and locally, triathlon registrations and some club memberships have dipped in recent years. Potential reasons include the cost of participating, time required for training and market saturation. But in Maryland, there are still thousands of triathletes like Montoya who are committed to the sport. And they are passionate about making it accessible and bringing younger triathletes on board to help it grow.

Triathlons, long-distance races where participants swim, bike and run, began in the United States in the 1970s. Their popularity grew in the mid-1990s, and in 2000, they became an Olympic sport. Growth continued through 2013, and then the sport hit “a bit of a plateau,” said Caryn Maconi, communications manager for USA Triathlon, the sport’s national governing body.

Between 2013 and 2014, annual USA Triathlon memberships dropped 2.7 percent. From 2014 to 2015, memberships dropped again by 5 percent. By the end of 2015, USA Triathlon had just over 161,000 members, down from 174,787 in 2013.

“After that great period of growth, it’s just hard to keep it growing at such an exponential rate year after year,” Maconi said.

Locally, USA Triathlon sanctioned 34 events and clinics in Maryland in 2015, compared to 50 in 2014. Membership in the Mid Maryland Triathlon Club has also dropped in recent years, said Tim Delss, club president. And the Columbia Triathlon, which drew almost 1,000 participants in 2016, is slightly behind in registrations this year, said Matt Florio, race director for Corrigan Sports Enterprises.

While the exact reasons for the decline aren’t clear, some said the variety of athletic events available in the region could be a factor.

“Ten years ago, we didn’t have things like the color runs, the mud runs, warrior dashes, even these new boutique gyms that are popping up,” Maconi said. “There’s a lot of different ways you can get fit now. So, people have a lot of choices. … I think it does have an impact on our membership, but I don’t think the options are a bad thing.”

The cost and time commitment can also deter people from entering the sport, triathletes said.

“Let’s face it: Triathlon is not inexpensive,” said Kim Franklin, a Baltimore resident and group workout director for the Baltimore Area Triathlon Club. “You have to buy a bike, and there are lots of pricey bike upgrades.”

Then there’s the bike shoes, helmet, glasses, wetsuit and pool membership, she said. And don’t forget about the race fees.

“For Ironman, the entrance fee alone is $800,” said Roy Cheeks, a Baltimore resident who began racing triathlons seven years ago.

For longer-distance triathlons, some athletes will train at least 20 hours a week, he said.

“Once you want to do a full [triathlon], that’s your life,” Cheeks said. “People have lost friends; people have lost significant others. It’s a lot.”

Still, there are signs that triathlons haven’t completely run out of steam. According to USA Triathlon’s 2015 membership report, the Mid-Atlantic region remains the largest of USA Triathlon’s 10 regions, representing about 16 percent (21,864 individuals) of the total membership. And the Baltimore Triathlon, an October event that reached its maximum 300 registrants the past few years, expanded to two dates this year to accommodate more participants.

“Many people find triathlon because they are looking for a healthy new challenge in life,” Delss said. “They stay because they find support, friendship and camaraderie in the triathlon community.”

To encourage future growth, USA Triathlon and local triathlon clubs are focusing on making the sport more accessible.

Club members share resources and even hand down equipment, Cheeks said.

“I had a lot of hand-me-downs for the first couple of years because I didn’t even know if I liked [the sport] yet,” he said. “Long story short, I ended up loving it.”

Both the Baltimore Area and Mid Maryland Triathlon clubs also run group training sessions, as well as programs where beginners are paired with experienced athletes.

“The benefit of being in the club is the learning opportunity, the friendships you make and the experiences you can share and learn from,” Franklin said. “It’s a great support system.”

USA Triathlon is pushing more short-course racing like “sprint” triathlons, which take about an hour and a half instead of a full day, Maconi said.

“We really want to show people that you can do a triathlon with an hour of training a day, five days a week,” she said. That’s the same amount of hours many already devote to exercise, she added.

USA Triathlon is also supporting growth at the youth, high school and collegiate levels. It hosts “splash and dash” aquathlon events, where youth athletes swim and run, throughout Maryland. Participants do not need bicycles for these events, making them more accessible, Maconi said.

Local organizations like the Mid Maryland Triathlon Club run youth triathlons, such as the TriAtholton Kids’ Triathlon on June 25 in Columbia. The goal is to give young athletes a chance to compete in a safe and fun atmosphere, said Bryan McMillan, race director. Kids can even use water wings and training wheels if needed.

Emily Greenwald, 11, of Ellicott City and Thomas Trumble, 13, of Elkridge plan to participate next month.

“I think it’s a good thing for more people to do triathlons,” Emily said. “You get to do three different things all combined in one. And most of all, it’s fun.”

Thomas, who completed and won his first triathlon at age 6, agrees.

“It’s a lot of fun, and you meet really nice people,” he said. “I never regret doing it. I always feel proud of myself at the end, and that’s what really matters.”

Registration is open for the Columbia Triathlon & Duathlon, held May 21 at Centennial Park in Ellicott City. For more information, visit trimaryland.com.