Lauren Swartz experienced a wave of emotions in her first marathon.

There was the excruciating pain at the 20-mile mark — also known as the “wall” for distance runners trying to complete the 26.2-mile race.

It was horrible, Swartz recalled, adding that she wanted to slow down. “It was so much worse than I thought it would be,” Swartz said. “My legs had no juice. I was feeling really discouraged. I wanted to stop. The longest distance I’d ever run was 22 miles.

“I was breathing really hard, obviously. My heart rate was way up.”

But as she came upon a water station during the Oct. 18 Humboldt Redwoods Marathon, a worker with the race notified Swartz that she was in second place in the women’s field, that only one female runner was ahead of her.

That was all the motivation Swartz, a 2004 UC Davis graduate who was an All-Monticello Empire League water polo player at Napa High School, needed.

She regrouped, picked up her pace and used whatever energy she had left to make a run to the finish line in Redcrest, Calif., winning the women’s title and placing 10th overall in a time of 3 hours, 27 minutes, 50 seconds.

That’s when another set of emotions took over.

“It was just totally thrilling, really, really exciting,” said Swartz. “I was really proud and I was really glad that all the training and all the effort that I put in had paid off that way.”

Laura Chapman of Arcata finished second (3:28:15) and Katie Hunter Arcata, the runner-up in 2006, was third (3:28:54). The 31st annual marathon, presented by Six Rivers Running Club, is held along the Avenue of the Giants in the scenic Humboldt Redwoods State Park, about 40 miles south of Eureka. The race starts at the Dyerville Bridge, near Founders Grove in Humboldt Redwoods State Park. The USA Track & Field-certified race is run almost entirely under a canopy of old growth redwood trees.

“The scenery was great,” said Swartz, adding there was a light rain with some wind.

Swartz went into the race with a goal of qualifying for the Boston Marathon, which ranks as one of the world’s most well-known road racing events, drawing runners from all over the world on Patriots’ Day in April.

She achieved her goal — and a whole lot more. For winning, Swartz was presented with several prizes, including a cash award, a gift certificate to an inn alongside Humboldt Bay in Eureka, and a commemorative glass plate.

“A lot of people told me that was maybe too much for my first marathon, but I knew I could do it based on my half-marathon time and I thought I could speed it up a little,” said Swartz, who works as an instructor at Exertec Fitness Center in Napa and for Portocock, a cork supplier, of Napa.

“I was really nervous, but I just stayed on my pace. I looked at the times from the previous year and I thought it would have been a stretch to win it, but I knew I could be in the top-10. I just knew if I ran what I should run, I had a good chance of doing well, which is why my parents (Cliff and Cara Swartz) went up to watch me.”

Swartz ran the marathon with her boyfriend, Jeff Ansley, who is a personal trainer at Exertec. She started running about 50 miles a week as part of a training program that Ansley set up for her back in March. Ansley also completed the race, placing 11th in 3:27:50.

“I wouldn’t have known what to do and I definitely wouldn’t have done as well if he hadn’t helped me as much as he did,” said Swartz, 27. “A lot of our tempo runs, from the stuff Jeff did with me, helped.”

It was only the second road race for Swartz, who ran the San Francisco Half-Marathon earlier this year.

“The most exciting thing for me was winning it. That was amazing,” she said.

Swartz said she has always liked to run, but never thought she’d do a marathon.

“Often times in the gym, people would ask me what I was training for, like when I was running on the treadmill or lifting weights, and I realized I wasn’t really training for anything,” she said. “I thought, well maybe I should apply this somehow and do something.

“I’m going to keep training.”

Her next marathon will be much closer to home. It’s the 2010 Kaiser Permanente Napa Valley Marathon, a 26.2-mile race from Calistoga to Napa along the Silverado Trail on March 7. Dedicated to fostering and promoting quality road racing, the Napa Valley Marathon is known as the “biggest little marathon in the West.” The race has earned a reputation for outstanding runner support, attention to detail, and a beautiful point-to-point course.

Swartz would like to take 10 minutes off her time that she ran at the Humboldt Redwoods Marathon.