Running and cystic fibrosis certainly aren’t “supposed” to pair together. After all, the progressive, genetic disease that leads to persistent lung infections and breathing problems over time causes major problems for those afflicted. Running with the condition? It’s nearly out of the question for most. However, not Michael Waltrip, a 24-year-old PhD student at George Mason University.

Waltrip, who ran throughout high school in his hometown of Murrieta, Calif. and in college at Cal State San Marcos, recently ran a marathon in San Francisco fast enough to qualify for the 2019 Boston Marathon. Note: The qualifying standard for men in the 18 to 34 age group is 3 hours and 5 minutes. He also won the Run Your Heart Out 5K in Virginia, clocking a time of 16:02, which equates to a 5:10 min/mile.

He was diagnosed with cystic fibrosis shortly after birth, but didn’t develop breathing problems until a few years ago.

He got his start in running at an early age when he got bored at his brother’s soccer game and asked if he could run around the track. His father figured he wouldn’t make it make one lap, but Waltrip far exceeded expectations.

He continued running into his teen years at Chaparral High School, where he was a four-year letterwinner in cross country, Rookie of the Year and won several team MVP awards. He also ran a personal best in the mile: 4:36.

Doctors believe running competitively helped combat his cystic fibrosis symptoms until they were finally too much and and reminded Waltrip that he had the disease.

“Until then, I think I didn’t acknowledge that I had CF because it wasn’t affecting me as much,” he told Runner’s World. “But then I came to the point where I couldn’t fall asleep because I couldn’t breathe properly, and I’d have to sit up and calm myself down for 30 minutes with breathing exercises.”

It took him half a year to finally give in to getting treatment for his breathing problems. He continued to train and run about 60 miles per week while undergoing a daily nebulizer treatment to combat the build-up of mucus.

“Just to be able to run with CF is kind of crazy and awesome,” he said. “But, like anything, you just have to focus on what’s in front of you today, and breathe the best you can.”

Good advice for anyone out there.