OAKLAND -- In less than 72 hours a wall of bodies will block 19th and Harrison streets waiting for the start of the Oakland Running Festival. When they hear the starting shot, thousands of runners will launch themselves from Snow Park down the narrow streets toward downtown and whatever goal they have set for the day.

For about 1,500 runners, that will be the full marathon, while 250 teams will be competing for first place -- and a trip to Hawaii -- in the four-person relay race. Others will run the half-marathon. But the 5K race has drawn the most people.

"That's the way we get the ball rolling," said Lee Corrigan, who is head of Corrigan Sports Enterprises, the organizer of the festival.

People who can run the full 26.2-mile marathon "don't grow on trees," he said.

The running festival began in 2010 as a spinoff of a similar event in Baltimore, also organized by Corrigan Sports.

"Five years, can you believe it?" Corrigan said Thursday during a pre-race news conference and luncheon at the Terrace Room on Madison Street, two-tenths of a mile from Sunday's starting line.

Joggers and walkers circling Lake Merritt could be seen in the background through the windows.

Just over 6,000 runners showed up the first year of the Oakland Running Festival. The number reached 9,300 in 2013. They came from 40 states and eight countries, including Japan.

Corrigan Sports staff would not release the exact number registered this year but said they are expecting 10,000 runners from 31 states and three countries.

"The first year there were a lot of doubters," Race Director Gene Brtalik said. "People kept asking if we're coming back."

Now the race has become a ritual in some neighborhoods along the course. On Sunday, there will be 21 bands, 11 cheer stations, 18 water stops and thousands of fans.

Golden State Warriors legendAlvin Attles, winner of a lifetime achievement award from the Basketball Hall of Fame, will help send off the runners along with the Raiderettes and former Raider wide receiver Kenny Shedd. Members of the Raider Nation will be stationed along the course. And two-time Olympic gold medalist Jim Hines, a graduate of McClymonds High School and sprint world-record setter, will be cheering runners on.

Half marathoners and hundreds of junior runners will set off for the Kids Fun Run and converge with the full marathoners on their course to the finish line. They'll hear Sheila E. performing on the main stage, giving them a boost to "finish their quest," Corrigan said.

Dean Karnazes, known for his ultramarathon track record, will be competing for the second year in a row and wearing a No. 1 bib on race day.

Weather forecasts for Sunday's 7:30 a.m. start call for 49 degrees, rising to a high of 70 degrees and "zero chance of rain," Brtalik said. Highland Hospital staff will be on site to help with any medical emergencies.

"The water situation is going to be paramount this year," Corrigan said.

Oakland running festival
What: Fifth annual Oakland Running Festival
When: Sunday, 7:15 a.m. opening remarks; 7:30 a.m. marathon and Hawaiian Airlines team relay races; 7:45 a.m. 5K; 9:15 a.m. half marathon; 9:20 a.m. Lucky Kids Fun Run; 11:30 p.m. awards ceremony
Where: Starts and ends at Snow Park, 19th and Harrison streets
Info: To sign up for events and to view the courses, go to www.oaklandmarathon.com. Runners can pick up their race packet or register 9 a.m. to 5 p.m. Saturday at the sports expo at the Oakland Marriott City Center, 1001 Broadway.