Athletes from throughout North Carolina and as far north as Vermont will descend on Washington this weekend for the fifth-annual Washington Triathlon.

Sponsored by Fitness Strong of Raleigh and Inside-Out Sports of Cary and hosted by the Washington-Beaufort County Chamber of Commerce, this year’s event includes for the first time the IOS100, a 100-mile race similar to a full iron-man competition.

“We’re doing something new this year. We usually do two weekends — a sprint and Olympic in July and a half iron man in October. This year, we’ve decided to do just one weekend and add the 100 race,” said Catherine Glover, the chamber’s executive director.

Races occur Saturday and Sunday, and they include a swim in the Pamlico River, a bicycle ride through the county and a run through downtown Washington. All races start and end on Riverside Drive on the Washington Park waterfront.

More than 150 athletes have signed up for Saturday’s races —the IOS 100 Triathlon, IOS 100 Aquabike, FS 50 Triathlon and FS 50 Aquabike — and nearly 100 folks are set to race in Sunday’s Washington Sprint Triathlon.

All of Saturday’s races start at 7 a.m. Sunday’s race begins at 8 a.m.

Racers tackling the IOS 100 face a 2-mile, open-water swim in front of Washington Park; an 88-mile bike ride from Washington Park out to U.S. Highway 264, down Jackson Swamp Road, through Bath, then along back roads back to Washington Park; and a 10-mile run between Washington Park and the Washington waterfront.

It’s likely to take some racers in the IOS 100 the entire day to complete the race, Glover was told by the sponsors.

Racers in the FS 50, the most-popular race of the weekend, do a 1-mile, open-water swim, a 44-mile bike ride and a 5-mile run.

Athletes in the IOS 100 Aquabike and FS 50 Aquabike complete only the swimming and bicycling legs of the races.

Racers in Sunday’s Washington Sprint Triathlon, the event’s second most-popular race, complete a 750-meter, open-water swim, a 13-mile bike ride and 3.1-mile run.

“We have a perfect location for the start of the season. We have flat land, warmer water, not much current. It’s a good location for the athletes to do their first race,” Glover said.

“Afterward, they hang out — shop, eat, buy gas. That’s the reason we do (the triathlon). It brings a lot of people to the community,” Glover added.

It was a little serendipidity and an East Carolina University connection between Glover and one of the owners of Finish Strong that helped establish the triathlon in Washington in the first place.

“They knew they could produce these events. They visited Washington looking for a good place. I knew Brent (one of the owners) in college. They decided Washington was a good spot,” Glover said.

Spots are available in all the races, but online reservations are no longer accepted. To learn more about the Washington Triathlon, visit www.wbcchamber.com, click on the events tab and scroll down to triathlon.