There will be something waiting for every runner who completes the New Balance Falmouth Road Race on Sunday.

Sweet relief that the race is over?

Perhaps, but with this year marking the 45th running of the event, race organizers are handing out medals for every finisher, commemorating every five years the event takes place.

The medal designs, however, will remain a mystery until race day.

“It is an interesting phenomenon in our sport that people are enamored with getting a medal at a race,” said Dave McGillivray, who is in his sixth year as race director of the Falmouth Road Race. “It doesn’t just go in the top draw. People are proud of that. It’s a big year in that regard.”

With the aid of about 1,800 volunteers plus hundreds of medical personnel, roughly 12,800 runners will take on the scenic, yet challenging, 7-mile course, which begins in Woods Hole at a starting line named after the race’s grand marshal, Tommy Leonard, around historic Nobska Light, through Falmouth’s rolling hills and ending by the beach in Falmouth Heights.

It’s considered by many the most iconic non-marathon running event in the country.

“Like the airlines say, we appreciate your business because athletes have a lot of different choices,” McGillivray said. “The fact that they return is a testament to the hospitality and the competitiveness of the event. We’re proud that we have a quality field each year.”

Leonard launched the race in 1973 on his 40th birthday to fundraise for Falmouth High’s track program. The original course was from Captain Kidd in Woods Hole to Brothers 4 in Falmouth Heights.

But he ultimately wanted legendary American distance runner Frank Shorter to run on Cape Cod. Back in 1972 as a bartender, Leonard watched on TV with delight as Shorter won the marathon in the 1972 Munich Olympic Games, becoming the first American to win the event since 1908.

Video: The Falmouth Road Race expo opens Thursday afternoon at Falmouth High School

With assistance from then-Falmouth High track coach John Carroll and former town recreation director Rich Sherman, the first Falmouth Road Race took off in 1973 with just under 100 participants.

However, a lesser-known (at the time) Bill Rodgers won the event in 1974, helping to bring Shorter to Falmouth for a showdown between the two in 1975 and 1976. Shorter won both matchups against the legendary Boston runner, but participants swelled to over 2,000 those years, giving the event the notoriety it needed to take off in popularity.

“It put Falmouth on the map,” said Jack Carroll, vice president of the Falmouth Track Club.

From there, the event has continued to grow from prize money, introduced in 1984, to turnout, which increased to around 10,000 in the 1990s.

Carroll will run his 40th consecutive Falmouth Road Race on Sunday, but he has also been housing Shorter for race weekend for the past 25 years.

“We look forward to that every year,” Carroll said. “It’s a celebration of running. That’s what Tommy wanted.”

Carroll is a racing veteran, but Ron Pokraka, 77, has him beat, running Falmouth all 45 years.

This year’s purse is $126,000, including $10,000 for the winner in the open men’s and women’s divisions, $7,000 total for the top three American men and women and $12,000 total for the top three wheelchair men and women.

The starting gun goes off for the wheelchairs at 8:40 a.m., the elite women at 8:50 a.m. and the gun for the rest at 9 a.m. The inaugural Falmouth winners, Jenny Tuthill and David Duba, will be honorary race starters.

The forecast calls for around 80 degrees and sunny with humidity around 65 percent.

Though plenty of medical professionals will be on hand, racers might have an extra level of protection.

Worried about not being spotted?

No worries, says McGillivray, who said the event, for the first time, will feature multiple two-person teams from RaceGuard, a non-profit program that provides certified in-race first-responders who wear special bibs and carry AEDs, in case of emergency.

“We have one of the best medical teams around,” McGillivray said. “Good news, no matter the temperature, people have had time to acclimate. That certainly helps keep everybody safe.

“We communicate to the runners what we’re seeing, and we try to guide them to pace themselves,” he added. “At the end of the day, it comes down to personal responsibility.”

Though the big race is Sunday, race weekend began with Wednesday night’s volunteer party, followed by Thursday at sunrise when the finish line was painted in red and blue on Grand Avenue with with the Falmouth Road Race and New Balance logos etched in white.

“When we paint the finish that is kind of a quintessential moment where it hits you that this is real and that we’re almost at our finish line,” said Jennifer Edward, general manager of Falmouth’s race management team.

Edwards also said 20,000 are expected at the race expo, which opened Thursday afternoon at Falmouth High School’s fieldhouse, the same place runners can collect their numbers from 10 a.m. to 9 p.m. today and 9 a.m. to 4 p.m. Saturday.

In addition to the various vendor stands, the largest being New Balance’s display with running gear for sale, there’s a TV in the corner playing a loop of the course video and in another corner, the blue gift bags for the runners.

The first racing gets underway Saturday with a series of mile races and fun runs at Falmouth High School’s outdoor track. Following the family fun run at 4 p.m., the Tommy Cochary High School Mile and Aetna Falmouth Elite Mile take place at 5 p.m. and 5:40 p.m., respectively.

This year, Nauset High School’s Tara Ellard and Madaket Nobili will be among 10 entered in the girls race.

In the elite mile, men and women will compete for the $15,000 purse, including $3,500 for each winner and $2,000 for second. New Zealand’s Nick Willis, a two-time Olympic medalist at 1500 meters, is among the elite men’s field.

Mark Curp won the 1988 Falmouth Road race, but he was the last American man to win the main event. Magdalena Lewy Boulet from Oakland, California, was the last American woman to break the tape first, doing so in 2011.

Both returning open champions are back as 29-year-old Kenyan Stephen Sambu is aiming to become the first four-time champion in the event’s history.

Last year the former University of Arizona standout tied Bill Rogers (1974, 77, 78) and Gilbert Okari (2004-06) as the only male three-time winners in the open division.

Caroline Chepkoech, 23, who won last year’s women’s title, will try to make it another Kenyan sweep of the open field. She won the $5,000 bonus last year for holding off Sambu in “The Countdown”, introduced in 2015 to create a competition between the men’s and women’s fields. This year’s countdown clock will be set at 5 minutes, 27 seconds, the average gap between the top finishers. It will start when the first woman crosses the line, giving the men’s winner 5:27 to finish in order to earn the bonus money.

“It’s a race within a race,” McGillivray said. “You have to run hard period. You have to decide if you’re trying to win your division or win the bonus.”

The elite women’s race begins at 8:50 a.m. Sunday, 10 minutes before the elite men’s and open race fields.

Sambu has won the event the past three years, but there are plenty in the open division looking to take him down.

Like New England Patriots quarterback Tom Brady, Abdi Abdirahman turned 40 this year, but the Somali-American and four-time Olympian is in the open field. In April, Abdirahman finished sixth overall in the Boston Marathon, crossing in 2:12:45.

Diane Nukuri, 32, the 2015 women’s winner who happens to be Adirahman’s significant other, is also primed to compete for the top women’s spot after finishing third (32:59) last year.

Nukuri, who escaped Burundi at age 16, skipped the closing ceremonies at the 2016 Rio de Janeiro Olympic Games to run Falmouth last year. She skipped this year’s World Championships to race the Beach to Beacon 10K in Cape Elizabeth, Maine on Aug. 5, taking fifth, and Falmouth.

A top American woman is Neely Spence Gracey, who won the Chicago Half Marathon last month and was the top American female finisher at the Boston Marathon in 2016.

Gracey, who trains in Colorado, first ran Falmouth in 2012, but she wasn’t the first in her family to run it. Her father Steve Spence won bronze in the marathon at the 1991 World Championships in Tokyo, and raced Falmouth twice, including a second-place finish in 1988.

The fastest competitors of the day, though, will come from the wheelchairs, led by women’s wheelchair legend Tatyana McFadden, the only athlete to win the Boston, Chicago, London and New York marathons. After winning four gold medals in T54 disability classification events at the 2016 Paralympic Games in Rio, the Russian-American McFadden is back this year after setting course records in 2014 and 2015. Her 2015 record of 26:27 still stands.

Last year’s champion American Yen Hoang, and Nigeria’s Hannah Babalola, the Beach to Beacon 10K winner, are also racing.

The men’s wheelchair division features last year’s champion Tony Noriega, Beach to Beacon champion Krige Schabort and course record-holder James Senbeta, who set the mark of 23:32 in 2014.

Aside from the elite competition, plenty will run for a greater cause, with over 100 non-profit organization teams listed on the race’s website. Some are Habitat for Humanity, Mass. General Breast Cancer Research, Dana–Farber Cancer Institute, the National Kidney Foundation and the May Institute for autism awareness.