On a cool, overcast morning Thursday, hundreds of Sonoma County commuters shunned their cars and hopped on bicycles to promote physical and environmental health on Bike to Work Day.

The 20th annual event, celebrated across the Bay Area as part of a month-long biking campaign, drew dedicated cyclists dressed in spandex on pricey road bikes as well as commuters in suits on comfy cruisers with bulging panniers.

They gathered at the more than 20 energizer stations around the county to fuel up, listen to music and talk about cycling.

"It's a good scene," said Lisa Ludwigsen, marketing team leader at Whole Foods. "Everyone is out having fun and being healthy."

Ludwigsen handed out fruit, juice, coffee and bagels at a booth sponsored by Whole Foods and Kaiser Permanente at Walnut Park in Petaluma.

About 80 cyclists passed by throughout the morning, including Evan Williams, who rides his fixed gear bike four and a half miles to work at Labcon in Petaluma three days per week.

"Traffic is terrible and it makes driving a nightmare," he said. "Biking is refreshing. It's a nice way to start the day."

Caroline Pope, who works part time from her home in Penngrove, rode her bike into Petaluma to hit the gym.

"I call it Bike to Workout Day," she said.

Participants included those who ride 20 miles or more to work every day to those who dust off their bike once a year for the event, according to Karen Langdon, with Kaiser Permanente. One cyclist was on his way from Tiburon to Calistoga, a 60-mile ride, she said.

"This day promotes health and wellness," she said. "And it takes cars off the road."

Across the Bay Area, tens of thousands of commuters were expected to participate in the event, according to the Metropolitan Transportation Commission.

At Prince Gateway Park in Santa Rosa, employees with outdoor retailer REI and cycling shop Bicycle Czar tuned bikes and gave out coffee and pancakes with bacon hot off the grill.

Brant Arthur, with the Santa Rosa-based Climate Protection Campaign, stopped by on the way to drop off his 5-year-old daughter, Cassidy, at school in a bike trailer.

"This is a good event for people to experience the bicycling community that's out there," he said. "A lot of people try it for the first time and hopefully make it a habit."

REI manager Lehua Taitano passed out water bottles and extolled the benefits of cycling as sales leader Wendy "Hot Cakes" Blackwell flipped flap jacks on a portable griddle.

"You are reducing (vehicle) emissions and saving gas money," Taitano said of biking. "Plus, you are getting in shape, and you look good doing it."

Bryan Mischke, a Santa Rosa resident on a ride to work at the Anthropological Studies Center at Sonoma State University, stopped to eat a plate of bacon-infused pancakes. He said he saves about $4 in gas money each day that he leaves his car at home.

"It's only about 10 minutes longer by bike," he said. "I get my workout in for the day."

You can reach Staff Writer Matt Brown at 521-5206 or matt.brown@pressdemocrat.com.