Spike Lee, Police Commissioner Bill Bratton Paint Line Ahead of New York City Marathon

Professional athletes from around the world and more than 50,000 recreational runners will gather Sunday to run the 45th annual TCS New York City Marathon, which many consider the most prestigious endurance running event in the world.

The 26.2-mile course will take participants through the city's five boroughs. Peter Ciaccia, events and race director of the marathon, deemed the event "New York City's biggest block party."

On Thursday, Bill Bratton, commissioner of the New York City Police Department, and film director Spike Lee, the marathon grand marshal, were among about a dozen honorees and sponsors who helped paint the ceremonial blue line that will lead participants to the finish.

Each year, the race includes Olympians, Paralympians, wheelchair racers, top age-group competitors and tens of thousands of runners who participate to achieve their personal goals or to raise money for charity. Among the expected notable runners are James Blake, a former professional tennis star who in September mistakenly was tackled by an undercover NYPD police officer, and Alicia Keys, a singer and New York native, and Meb Keflezighi, an Eritrean-born American Olympian who won the marathon in 2009.

The race began in 1970 with just 127 entrants racing four laps around Central Park. Now, the route starts at the base of the Verrazano-Narrows Bridge in Staten Island, and snakes through diverse neighborhoods in Brooklyn, Queens and the Bronx, before it ends in Manhattan's Central Park. Millions of fans are expected to gather on the roads to cheer the diverse group of runners.

"They call it a race like no other, and it really is because this was a race that started it all. They literally shut down the city," Bart Yasso, Runner's World chief running officer, tells Newsweek. Organizers have been using the same course—with minor tweaks—since 1976.

"People get views that you never get to see," Yasso says. "You basically take over the streets of New York City. You never get to do that."

Organizers created five different start times to handle the thousands of participants. The first wave, composed of the professional women, will start at 9:20 a.m. ET. The last wave is scheduled for an 11 a.m. ET start. In 2014, the average finish time for racers was 4 hours, 34 minutes and 45 seconds, according to the marathon's website, and 50,530 participants crossed the finish line.

Thursday marked the third anniversary of Superstorm Sandy, which in 2012 severely damaged parts of New York and New Jersey, and led race directors to cancel the event. But the forecast for Sunday shows mostly clouds with temperatures around 50 degrees Fahrenheit for the early morning hours, according to the Weather Channel. Temperatures are expected to settle around 65 degrees by the afternoon. The expected weather appears more favorable than the previous two years' cold and windy conditions.

Wind causes many runners to start the race cold, Yasso says. But without such conditions this weekend, runners have "no excuses."

"This looks like really ideal weather for not only the runners, but the volunteers, spectators," he adds. "I think everybody is going to be happy."