Park Slopers are fretting that Mayor Bill de Blasio’s frequent jaunts to the gym have put them in danger.

Brooklynites who frequent the Prospect Park YMCA on Ninth Street — where Hizzoner treks near-daily from Gracie Mansion to work out and where a racist bomb threat targeting the mayor was phoned in to police Wednesday — say they could end up in harm’s way themselves.

“It’s not fair,” said Stanley Garcia, 58. “He’s risking the lives of the young ones that come here. He could be somewhere else. They’ve got Crunch, they’ve got Blink.”

“To come down here from Manhattan, they have so much in Manhattan,” the Crown Heights resident said.

Police said they received the bomb threat in a 911 call at 7:15 a.m., with the unidentified female caller stating that the gym “is going to blow up when Mayor de Blasio goes there because he is running for president and he loves black people.”

De Blasio was on his way for his regular workout when the call came in, and ducked into Colson Patisserie while the gym was searched by cops from the nearby 78th Precinct.

The mayor got in his workout around 8:30 a.m., and left at 10:15 a.m. and left without incident.

But not before freaking out some neighbors.

“I wasn’t here, but I saw the email they put out about it,” said Emily Denn, 35, a gym member who lives a few blocks away – and had her 2-year-old daughter in tow. “I’m not sure why he comes here. It’s a long way to go. It’s just not good.”

Another local Y member who declined to be named agreed.

“I think he needs to find a Y closer to where he’s at,” she said. “He lives in Manhattan, go to one there. I don’t think it’s right to everybody else. And it scares the kids.”

De Blasio spokeswoman Freddi Goldstein fired back that the gym “is arguably the safest gym in New York City considering the mayor is always accompanied by several members of the NYPD.”