Shalane Flanagan takes a victory lap following her victory in the women's 10,000-meter final in the 2008 U.S. track and field championships. (Jonathan Newton/THE WASHINGTON POST)

As Olympic bronze medalist Shalane Flanagan competes in Thursday’s grueling 10,000-meter final at the U.S. track and field championships in Eugene, Ore., she will have 30-plus taxing minutes to mull a question that has nagged her since she finished second in her debut marathon in New York last fall.

Is she more likely to bring home another Olympic medal next summer by running 26.2 miles through London’s streets? Or by circling the track oval in the Olympic stadium a dizzying 25 times like she did in 2008, when she became just the second American woman ever to win an Olympic medal in the 10,000?

Her stunning success on the track suggests she should stick to the track. Her extremely limited, but no less stunning, success on the road suggests she should stick to the marathon. Only one element of the debate is clear: She cannot, because of the proximity of the two races on next year’s Olympic schedule, do both.

Her performance Thursday might help to bring some clarity; she is expected to qualify easily for the August world championships in Daegu, South Korea, where she will forgo the marathon for the 10,000 race. Depending on her result Thursday, she might also compete in Friday’s 5,000.

“I love everything about the marathon: the training, the commitment, the passion,” Flanagan said during a phone interview last week. But “I don’t think I’ve reached my full potential in [the 10,000]. I think this summer will be a good indicator, give me a good indication that maybe I shouldn’t leave the track.”

But she very well may leave it anyway.

She plans to return to heavy-duty road training after the world championships to ready herself for the U.S. Olympic marathon trials in Houston in January. Her performance in that race — which precedes the U.S. Olympic track and field trials by five months — could decide the issue for her.

“When I think of London, I probably think of myself more so running the marathon than being on the track,” she said. The track “is a really difficult environment. The track is really intense. The people are right there on top of you in a stadium. Track racing is hard. It’s really painful.”

But, Flanagan added, “with the marathon, you have to have a lot of patience. In that event, the buildup is very draining, very taxing. It’s almost like, if it doesn’t go well, it’s like someone broke up with you. A bad break-up.”

If that sounds a bit dramatic, consider that Flanagan has an unusually emotional attachment to road racing. She grew up with marathon stars as parents and moved from one road-running hub (Boulder, Colo.) to another (just outside Boston) as a child. Some Bostonians dream of playing for the Red Sox or Celtics, or going to Harvard. Flanagan stood on the sidewalk during the Boston Marathon year after year and yearned to compete in that race.

Her mother, Cheryl Treworgy, once owned the American records in the 5,000 and three-mile events, and claimed the world record in the marathon after logging a time of 2:49:40 at a 1971 race in California. Her father, Steve Flanagan, hung out with the likes of Frank Shorter and notched a personal best of 2:18 in the marathon.

“I thought everyone’s parents went and ran every morning,” Flanagan said. “I just thought that was a way of life. I used to beg my parents to run around the block with them when they were finished. . . . I remember both of them always being in running clothes.”

Flanagan clocked a 4:46 mile during her senior year at Marblehead High in Massachusetts and ended up on scholarship at North Carolina, where she met future husband Steve Ashley Edwards, a 400-800 runner. At Chapel Hill, she won a pair of national cross-country titles.

After failing to reach the finals of the 5,000 at the 2004 Olympics in Athens, Flanagan missed all of 2006 while recovering from surgery to remove an extra bone in her foot. In her first race after a 17-month layoff, Flanagan set the American record in the indoor 3,000. Two months later, she set the American record in the 5,000 outdoors.

“She’s just an incredible athlete, very tough, very tenacious,” said former George Mason coach John Cook, her coach at the time. “This is not a dilettante sport. It’s a street sport. It’s a hard sport. Shalane is just a tough kid.”

Early in 2008, Flanagan crushed Deena Kastor’s six-year-old American record in the 10,000 by 17 seconds. Once again, it was her very first race at the distance. After that shocker, she earned an equally jaw-dropping bronze at the 2008 Summer Games in Beijing. She lowered her American record in that race to 30:22.22.

She had almost dropped out of the race after contracting a case of food poisoning just days before the event.

“It was almost like a huge sense of relief [just to compete],” Flanagan said. “I felt like there was no pressure anymore. Pretty much everything that could have gone wrong had gone wrong, and I felt fortunate to be on the starting line at that point. I felt really calm and relaxed. [The race] was almost like an out-of-body experience. It was just one of those moments that you savor forever.”

After that string of successes, Cook wanted to push Flanagan to even better times in the 5,000 and 10,000. But Flanagan yearned to go home. She wanted to run a marathon. A few months after the Beijing Games, she moved to Portland, Ore., to train under distance guru Jerry Schumacher. After logging as many as 140 miles per week, she found running New York’s five boroughs and putting up a time of 2:28:40 — 20 seconds behind the winner from Kenya Edna Kiplagat — less painful than she expected.

Two months later, she became the first non-African in seven years to win a medal at the world cross-country championships, where she claimed a bronze.

The flood of success has given her two great opportunities — and one giant headache.

“She obviously does an excellent job at just about everything she does, whether it’s cross-country, the roads, from 1,500 up to the marathon,” Schumacher said. “It complicates things . . . but it’s a great dilemma to have.”