The 50th annual New York City Marathon kicked off Sunday after it was canceled last year due to the pandemic.

More than 30,000 runners registered to participate, according to New York Road Runners - the official registration site for the race.

That number is 20,000 down from the 2019 marathon, which brought in over 50,000 people.

To participate in this year's marathon, participants had to show proof of at least one dose of a COVID-19 vaccination.

Along with those participating, more than 1 million spectators were out in the streets to cheer runners on along the 26.2-mile route.

Mile 20 of the New York City Marathon brought runners into their fifth borough of the day, the Bronx, to finish the last six miles and fans there ensured they did not hit the wall out of exhaustion.

"I don't think it's the wall, I think it's more of a power boost. They're in pain now, but by the time they leave us, the adrenaline takes over as they go into Manhattan," said Eloy Suarez, of the NYPD Running Club.

Mile 20 is known to be the mile marker when runners begin to run out of steam, which is why the fans came prepared to soothe muscles and surge spirits.

"Some people need the rollers for the legs because you're getting cramps and some need a little bit more sugar. Other people just need to see a friendly face," said Ulrika Bengtsson, of the Bronx.

From cow bells to cups of soda, when runners arrived at the Bronx, they were taken care of and carried through to the finish line.

"The boogie down Bronx shows you the love with some hersheys and some candies, some jellies, I love it, I'm really tired, it picks my energy up, the music is fabulous. I'm not feeling the wall today, I'm good," said runner Carmen Balentine.

Runners left the Bronx almost as quickly as they entered before the headed back to Manhattan for a Central Park finish.

Plenty of fans also lined the streets in Flatbush to cheer runners on.

First time runner Sydney Grajeda ran for her brother who was injured in a ski accident that left him disabled. She ran for Wheeling Forward, a nonprofit that supports New Yorkers who are paralyzed or have disabilities.

"She wanted to do something she felt like her hands were tied. She reached out to this organization back in the spring and she asked how she can volunteer and they came back to her and said, 'your running!'" Grajeda's mother, Carol, explained.