A hopeful for the city's highest office challenges Mayor Bill de Blasio to find a new way to get to the gym.

Democrat Sal Albanese, who says he hopes to become the city's "mass transit mayor," gathered with some supporters at the YMCA in Park Slope, where de Blasio is a member.

The mayor has come under fire for getting driven in an SUV from Gracie Mansion to his workout in Brooklyn every morning instead of taking mass transit.

Albanese also urged the mayor to take the train to City Hall.

"It's about his work, his work ethic. It's about the environment. It's about, why would you drive 12 miles to sit on an exercise bike to stay in touch with your roots? That doesn’t make any sense," Albanese said. "And it's also his arrogance. Instead of changing his behavior, because the critics, including myself, have made some excellent points. 'Why are you doing this?' No. He’s going to continue to do it, critics be damned. And he doesn’t understand the impact it has.”

De Blasio had apparently left the gym by the time Albanese arrived Wednesday morning. 

The mayor has defended his routine, previously saying if he switched to mass transit, it would be "cheap symbolism."