*This story was edited to reflect a change.

Imagine being a young, competitive athlete derailed by a rare headache disorder and learning physical activity -- 3 to 4 hours per day -- was its primary treatment. That was essentially the mutually benefiical situation for then 15 year-old Tessa Barret, now a senior in high school and the reigning high school girls cross country national champion, letsrun.com reported.

Like many runners, Barret began her athletic career in another sport and converted to cross country as a freshman because the prep school she attended did not offer field hockey, her preferred choice. She experienced instant success, until by the end of her freshman season her life became an on and off battle between racing (she still ran well, posting a 5:20 in the mile) and debilitating headaches, Penn Track XC reported, a MileSplit.us affiliate.

At the end of her freshman year, Barret and her parents sought answers at the Headache Institute at the New York-Presbyterian/Columbia University Medical Center, the leading facility of its field. After a significant period of testing, they diagnosed Barret with a condition called Atypical Migraine Syndrome and discovered its primary trigger was fluorescent light, according to Penn Track XC.

Unfortunately for Barret, the ceiling of almost every school building, right next to that material so receptive to sharpened pencil points, is covered in fluorescent lights. At the end of her sophomore year of high school, she enrolled in an online school and was allowed to compete for the local public high school, Abington Heights.

Besides avoiding fluorescence, doctors also prescribed her 3 to 4 hours of exercise per day, an absurd rate even for a competitive runner like Barret. As of her junior year, she was only running 25 to 40 minutes per day. Aided by her employment at a gym, she supplemented her running with pushups, sit ups, pull ups, and swimming. Her legend grew; so did her muscles.

After a successful junior year derailed by a season-ending virus, Barret would enter her last season slightly under the radar. Her upset win at nationals over the year's fastest girls in the country was questioned by several coaches who wondered if she was on drugs. Some even wrote into the famous running website, letsrun.com, and asked its editors if they believed she could be on PED because, as letsrun put it: "She's improved so much and she's jacked." One site thread claimed she did 200 pushups and 90 chin ups every day.

Barret's condition should improve with time and "eventually even out", according to a quote she gave Penn Track XC. Until then, she'll be staying active nearly a third of her waking hours to both fight her condition and improve her times.