Updated

Facing brutal wind and 40-degree temperatures at the 2016 Philadelphia Marathon, there were moments when Steve Sinko wondered if his running partner, Preston Buenaga, was enjoying himself. Towards the middle of the race, Buenaga shifted in his chair. Was he uncomfortable? Bored? Runners next to them offered encouragement. The massive crowds along the road roared as they passed.

This was Buenaga's second marathon—and by far the biggest race he had ever been involved in. Sinko watched his friend look around and take it all in.

Sinko, a 40-year-old personal trainer and high school track coach from Wilmington, Delware, ran the marathon on November 20 while pushing 18-year-old Buenaga in an adaptive running chair. Buenaga has Mitochondrial disease, which causes cellular damage and leads to low muscle tone and developmental delays.

Completing 26.2 while pushing 180-pounds (the weight of Buenaga plus the chair) is a feat in itself, but Sinko made it through the finish in a speedy 2:56:39.

Want to run your first marathon? Get a training plan from Runner’s World.

“The faster he can go, the happier he is,” Sinko said of Buenaga. “He loves being out there.”

Their journey together started in 2014 at a fundraiser for Preston’s March for Energy, an organization created by Buenaga’s parents, Deb and Steve, to raise money to provide adaptive bikes for children with special needs. After getting to know Deb Buenaga—who has run many races with her son—Sinko, a 14-time marathoner, asked her if he could try pushing him in a 5K race. The pair went on to complete two more 5Ks.

“After we finish our runs together, he’ll mess with me a bit,” Sinko said. “I’ll be like, ‘did you have fun?’ And he’ll give me a funny look. But he can only hold that look for a couple of seconds until he gives this big smile.”

It was that smile that convinced Sinko to sign up for the Philadelphia Marathon at the end of May. Once they were registered, Buenaga couldn’t stop talking about the race. Sinko was excited, but understandably nervous; he had never pushed anyone in a race longer than a 5K.

Podcast: Get More Inspiring Stories from “The Runner’s World Show”

He knew the best way to calm his nerves would be to get himself in top shape, so he logged 55 miles per week while pushing his partner. If Buenaga couldn’t run with Sinko, he’d load up the chair with 140 pounds of dumbbells or sandbags instead. He even took his father, who weighs over 200 pounds, out for a run.

His training went well, so he made a bet with a friend that he’d finish in less than three hours. Sinko had run Philadelphia once before, but never with another person depending on him to finish. These two factors propelled him to run even faster.

Despite the wind, the first six miles were flat and easy, but soon after the roads started to wind and crown, making the chair hard to push. “There were more hills than I remembered,” Sinko said. “The really big one at Mile 9.5—that one kicked my butt pretty good. I slowed down a little bit the last couple of miles, but we were able to get it together for a nice big finish.”

As the pair crossed the finish line, Sinko looked down. He couldn’t quite read the look on his partner’s face. But Buenaga couldn’t hold out for long; he cracked a smile. The next day, he wore his race medal to school.

“It was really something powerful to be a part of,” Sinko said. “It just shows the power of inclusion and what it can do at races. The Philly Marathon was a great example of that.”

And although Sinko and Buenaga have nothing specific coming up, they will definitely continue to build their partnership.

“It’s very rewarding for people on both sides of the chair,” Sinko said. "I love running with Preston. I know we’ll be training together for a long time.”

More:

The Best Gifts for Runners

30 Gifts Under $30

Guy Runs 50 Miles on a Treadmill. Also Sets Record

This article originally appeared on RunnersWorld.com.