CAMBRIDGE, Mass. — Dacie Manion is happiest when she is striving for perfection.

That is true whether she’s training with her teammates or trying to maintain a 5.0 grade point average at the prestigious Massachusetts Institute of Technology.

The 18-year-old sophomore from Old Town balances a rigorous course load, studying toward a mechanical engineering degree, with competing on the Engineers’ cross country and track squads.

MIT is home to some of the brightest and most motivated students in the world.

“Dacie’s an exception to even MIT students,” said MIT cross country and track coach Halston Taylor. “She’s just a model of efficiency. She does not waste any time at all. Everything is productive.”

Those qualities could mean a frustrating December for Manion, who was diagnosed this week with a stress reaction in her right leg. The injury sidelined her toward the end of the cross country season.

She will be unable to run for four to six weeks while she wears an air cast, but she hopes to resume training in January.

“On the plus side, it will give my body a rest,” Manion said. “I will be thinking of nothing else other than racing by the time I get to run my next race.”

In the meantime, she plans to “run” in the swimming pool. She admitted the down time will be unsettling.

“Even vacations are sometimes hard for me, because I don’t feel like I’m accomplishing enough,” Manion said.

The cross country season ended Nov. 17 with MIT’s trip to the NCAA Division III Championship at Terre Haute, Ind. Manion attended as an alternate because of injuries.

In her last race, the New England Men’s and Women’s Athletic Conference Championship, she finished seventh.

While the Engineers earned sixth place at the nationals, Manion came back with some special hardware. She received the NCAA’s Elite 89 award, which is presented to the student-athlete who boasts the highest cumulative GPA at each of the NCAA’s 89 championships.

“Rarely do you see students like Dacie come along,” said Dr. Peter Dourmashkin, Senior Lecturer in Physics at MIT. “She’s incredibly enthusiastic, she loves being at MIT and she really enjoys the classes. Students like her are a pleasure to teach.”

Similar sentiments were expressed by people at Old Town High School, where Manion was the valedictorian of her class in 2011.

She ran cross country and track for the Coyotes, was Key Club president and served as the battalion commander of the school’s Junior ROTC program.

“She’s a fabulous young lady,” said Old Town principal Scott Gordon, who called Manion mature beyond her years. “She was extremely well-organized. She never wasted a moment of time.”

Manion believes her self-motivation and hunger for achievement stem from the influence of her parents.

Lynne Manion, Ph.D., is a communications instructor at Northern Maine Community College in Presque Isle. Will Manion is a civil engineering professor at the University of Maine.

“They never let me settle for anything because they knew I could do better,” Dacie said. “They carefully pushed me to the extent that I could work harder without pushing me to the extent where I hated it.”

Dacie Manion’s quest for success wasn’t confined to the classroom. She joined the cross country team as a sophomore in 2008 and became a top-notch runner.

Old Town cross country and track coach Rod White said the 5-foot-1 Manion, who isn’t the prototypical thin, lanky distance runner, worked her way to excellence.

“I don’t think she necessarily has tremendous natural [athletic] ability, she has to work for what she gets,” White said, “but she improves as she works. She puts tremendous effort into everything.”

Manion placed fourth in Eastern Maine and eighth in the state that season, then went on to win the Class B regional cross country title and take third at the state meet in 2009.

As a senior, Manion went undefeated against EM competition en route to individual championships in the regional and state championships. She ended the year with a 10th-place finish at the New Englands.

“Her senior year was one of the most amazing I’ve ever coached,” White said of his 30-year career in coaching.

Manion capped her high school career in outdoor track, winning the Penobscot Valley Conference large-school and state meets in the 3,200 meters in 2011.

“As far as the athletics and the academics, the will, everything together, she’s probably the best I’ve ever coached on the girls’ side,” White said. “If she wants something, she’ll probably get it.”

Never satisfied, Manion made sure her college choice would provide significant challenges to test her both mentally and physically.

At MIT, there would be plenty of expectations placed on her to complement her own aspirations.

“It’s hard to self-motivate all the time,” Manion said. “It’s easier when you have examples all around you.”

She admitted the first year was stressful as she came to terms with the realization that it’s OK not to get a 100 on every exam.

“It’s taken a while to realize that perfect is not the only form of success,” Manion admitted.

She has encountered a similar dynamic in athletics at MIT, where Manion faces a higher level of competition.

This fall, she was among the top six or seven runners on the cross country team. She is no longer running at the front of the pack.

“She’s one of the major contributors on the team, both cross country and track,” Taylor said.

“She tries to get perfection,” he added. “She knows that’s not possible, but she nevertheless strives for it.”

Manion’s place in the team hierarchy has given her the opportunity to view things from a different perspective.

“It’s different and it was hard,” she said of the adjustment. “I knew when I graduated from high school that I was going to a college where I wasn’t going to be the best at anything any more.”

Rather than setting the pace, Manion receives inspiration from her teammates, both those she is pursuing and those who are chasing her during races.

“I can push myself to higher levels of achievement when I’m behind than when I’m ahead,” she said. “That’s why I came to MIT, for motivation.”

Manion excelled indoors last winter, when she finished third in the 3,000 meters at the New England Division III Championship.

Running has provided Manion with an outlet to alleviate some of the stress that accompanies the demands of her academic program. She also is minoring in biomedical engineering and Mandarin Chinese.

“If I didn’t run, I don’t think I could handle MIT,” Manion said. “Running is a really important break during the day.”

Manion relishes the opportunity to interact with her teammates during their daily workouts.

“I come out of practice happier and more relaxed and ready to go back and work on homework,” she said. “I couldn’t do without it.”

Doumashkin observed that after overcoming some initial anxiety about the subject matter in his physics classes, Manion exhibited a knack for sharing her knowledge and insight.

“She really loved interacting with the other students,” Doumashkin said. “I really counted on her all semester long to work with her group and explain and help them solve problems.”

Manion might be slowed by her walking boot, but she’ll continue working her way back. In the meantime, she’ll look to finish the semester by maintaining her 5.0 GPA.

She might even catch an episodes of the sitcom “The Big Bang Theory,” one of her few TV indulgences. It includes among its main characters Howard Wolowitz, an MIT engineering graduate.

However, Manion hates to waste time.

“When I accomplish things in life, those are the times when I’m happiest,” she added. “I really love MIT because it gives me the chance to accomplish more than I ever thought possible.”

Pete graduated from Bangor High School in 1980 and earned a B.S. in Journalism (Advertising) from the University of Maine in 1986. He grew up fishing at his family's camp on Sebago Lake but didn't take...