The new Dougherty Valley High School had the most participation among district high schools with 13 percent. Rancho Romero won for elementary schools with 69.6 percent taking part.
"It's a banner year," said foundation director Vanessa Chan. "This year's run was a record breaker."
Rancho Romero was followed by Tassajara Hills Elementary, which had 43.2 percent participation, and John Baldwin with 34.7 percent.
Charlotte Wood led the middle schools with 21.9 percent. Stone Valley received an honorable mention for coming in a close second with 20.9 percent.
The winner of the half marathon (13.1 miles) was 24-year-old Alex Cardiasmenos, whose time was 1:14:34. The winner of the 5K (3.1 miles) walk/run was Dmitry Kislyuk, 17, of San Ramon with a time of 15:37.0.
Gold sponsors for this year's Primo's Run were Shapell Homes, Comcast, Forward Motion Sports, Brookfield Homes, Primo's and Clif Bar.
-Dolores Fox Ciardelli