David Watts waited until his early 50s to get into the triathlon circuit.

Now he’s addicted and looking forward to Sunday’s Half Ironman in Augusta.

“The swim is really good,” said Watts, 58, of Wayne. “You never normally get to swim in the Kennebec. It’s a fast swim. It’s a challenging but scenic bike course.”

The race — officially called the Ironman 70.3, a reference to the total distance of the swim, bike and run — returns to Augusta for the second year of a three-year stint in the capital region.

About 2,200 athletes are signed up to compete, including 60 professionals who will vie for a $30,000 prize, according to Ironman.

The competition features a 1.2-mile swim in the Kennebec River, a 56-mile bike ride and a 13.1-mile run.

Organizers say it gives a major boost not only to local hotels and restaurants, but the entire state as well.

“Some of the folks who were here last year are already in town and are visiting Bar Harbor, Camden, Rockport,” said Earl Kingsbury, Augusta’s director of community services.

Last year on the Friday before the event, it took two hours to get lunch at Hallowell restaurants, said Katie Doherty, Kennebec Valley Chamber of Commerce president and CEO.

This year, local businesses know what to expect and are ready for the rush of athletes and their families, Doherty said. In addition to being aware of traffic impacts on Sunday morning, she said locals should also be ready to be patient.

“These people are excited to be in the area and see the region,” she said.

While the swim begins and ends in Augusta, the bike course stretches from Augusta to Dresden, where racers will cross the Kennebec River Bridge to Richmond and head west. Their loop will take them through Litchfield, Gardiner, West Gardiner and Hallowell, ending back in Augusta.

Then the run is mostly along the Kennebec River Rail Trail.

Starting at 11:30 p.m. Thursday, the north end of Front Street in Augusta will be closed through Sunday; at noon Friday, the Eastside Boat Landing in Augusta will be closed until 10 a.m. Sunday and on Sunday, Arsenal Street from Cony Street to Route 9 will be closed from 5:45 a.m. to 3 p.m.

In Hallowell, starting at 10 p.m. Saturday, no parking will be allowed on Water Street downtown or on Middle or Lincoln streets, according to the Hallowell Police Department.

Granite City Park, a popular spot for rail trail users, will also close at 6 p.m. Saturday.

Drivers on more than 24 area roads can expect delays, mostly from about 7 a.m. Sunday morning through around noon as competitors complete the bike leg of the course.

For racers like Watts, who works in sales and helps train others for triathlon events, the competition is a test of mind and body.

“There’s a mental toughness to it,” he said. “It’s not for everybody but everybody can do it. A lot of it comes down to willpower. Can I push through those last few miles on the bike?”

Another boost comes from volunteers and strangers who cheer them on.

“The most amazing thing is the supporters on the side of the road,” he said. “You don’t know them. That for me has gotten me over the line.”