The people hitting the floor to do pushups are trainees being whipped into shape so they will be fit enough for the physical rigors of a job in the construction trade.
The trainees also study everything from carpentry to blueprint reading, from advanced mathematics to how to install solar panels on a roof.
"The work that we're doing here is good for the economy and it's good for the environment," said Emily Courtney, the Green Jobs Training coordinator at Laney College -- one of the two training centers for the Green Jobs Corps. "It's the most cost-effective way to reduce greenhouse gases, and it's the most cost-efficient way to put people back to work."
The program provides 16 weeks of training for free and graduates about 130 people a year. Even in this weak economy, most of them get jobs, according to Art Shanks, executive director at the Cypress Mandela Training Center.
"We're batting about 75 percent in the total graduating class," Shanks said. "It's the best we can do at this time. Prior to the recession, we were batting 90 percent placement for each class."
Shanks introduced us to Mary Vanek, a 39-year-old mother of five, who graduated from Cypress Mandela's program last year. Before the program, she was barely scraping by on odd jobs. Now, she works for Turner Construction, helping to build a new hospital in Burlingame.
"I look forward to going to work every day. I don't think I've ever done that in my life," Vanek said.
We also traveled to Daly City, just south of San Francisco, to meet Angela Davis, who graduated earlier this year from the Green Jobs program at Laney Community College. She was on her break from installing energy-efficient windows at a low-income housing development. Before she was accepted into the training program earlier this year, Davis was out of work and living in a homeless shelter.
"I wasn't able to buy a dollar hamburger," she said. "I wasn't able to have bus fare to get on a bus to even look for work."
Davis loves what she is doing and has become an environmental zealot through her work at the Community Energy Services Corp., a nonprofit group that makes energy improvements to local residents' homes. She now rents an apartment and has had steady work since finishing the training program in July. She says her life has been utterly transformed.
"This program provided for me just the stability of employment, a career and being able to provide for myself," she said. "It's amazing."