Was That the Dipsea or the Boston Marathon?

San Anselmo’s entered the Dipsea Race for the first time Sunday because, she admitted, she liked the idea of getting a 12-minute head-start.

But it wasn’t what happened at the start of the race that had Fredricks excited afterward. It was the finish.

The 45-year-old mother of two who decided last year she’d rather be racing on bike than on foot made her first competitive Mill Valley-to-Stinson Beach run a winning one, capturing the win in the Runners Section of Marin’s most famous race.

“Living in Marin County, you can’t not know about it,” she said of the Dipsea. “For years, I avoided it. It was so hyped, it was overkill. Everyone talks about their training.

“Then a couple years ago, I went to watch a friend at the start. It looked fun. This year I thought: I’m 45. I’ll get a 12-minute handicap. If I’m ever going to do it, now’s the time.”

Even with a head-start, Fredricks ran into a lot of traffic along the 7.5-mile course because of her start in the second Runners Division, instead of the first Invitational Division. That wasn’t surprising. But something else she encountered was.

“With all the people, I didn’t know how it would affect me,” she said of her ability to keep at her preferred pace. “But only the stairs (near the start) were really crowded.

“I must have said “on your left” a thousand times. Most people were so friendly, willing to get out of the way. That was nice.”

After one of her passes on Cardiac Hill, Fredricks was told she was in the lead of the Runners section. Shortly thereafter, she experienced something she’s likely to remember a lot longer than the dozens of congratulatory e-mails (including one from running star Mike Sanelli) and phone calls she’s received subsequently.

“When I got to the bottom of the hill, the cheers were just unbelievable when they called: ‘First in the Runners Section coming,’” she observed. “Just to run down that stretch with everyone cheering, I thought I’d won the Boston Marathon.

“I had no idea it was that big a deal. I’ve gotten so many calls and e-mails, it’s kinda embarrassing. I’ve had bigger accomplishments.

“I mean, it’s a great moment and it’s been fun, but it was very unexpected. It would be one thing if I won the Dipsea, but this is just the Runners Section. It seems a little silly to get all this attention, but now I’m totally sucked in.”

First-time racers have to start in the second Runners Division before they can qualify for the Invitational Division that starts first. It is virtually impossible to win outright from the Runners Division, but an award is given for the winner of that section.

Leading the cheers were Fredricks’ husband Steve and daughters Emma (12) and Haley (9). The girls have taken up running at an early age at and , respectively, something Mom didn’t do despite having three sisters who participated in track and cross-country, and a mother who helped coach the sports.

“They came to it on their own. I never wanted to push them into it,” Fredricks said of her daughters’ love of running. “I’m happy they like my passion, but it doesn’t have to be their passion.

“Getting up that early (on Dipsea race day) wasn’t much fun for them. But they enjoyed it once they got there.”

Fredricks, a Los Altos native, didn’t enjoy running much as a kid. Her primary sport was gymnastics. But once in a while she would enter a race because the rest of her family did, and she often beat her sisters.

“Just to get the race over with, I guess,” she explained of her success.

Then in college, when she kept getting stress fractures in the same leg and saw several fellow gymnastics competitors bowing to surgeries, she asked herself what she could do that was quick and easy.

“Running,” she concluded. “You can even do that at midnight after studying.”

Fredricks went on to race marathons and eventually won the Grand Prix Short Series for Masters, a Northern California runners circuit.

“I guess that would be my biggest (running) accomplishment,” she admitted.

After getting bored of running roads, she took up bike racing. She believes that conditioned her well for a return to competitive running at the Dipsea.

“I like to mix things up,” she noted.

That helps explain the stab at the Dipsea. That and the head-start.

Fredricks said she thought she was capable of covering the Dipsea course in 1 hour, 3 minutes – and, amazingly, that’s exactly what she did.

“It’s quite humbling,” she said of her first Dipsea experience, “but something that might just happen once in my lifetime, so I guess I should appreciate it.”