Sometimes in the dead of winter, when Josh Buch bundles up to head out and teach an 8 a.m. finance class at La Salle University, he asks himself, “Why do you still do this?”

“Then it hits me: Lucky me that I can do it,” he said. “Lucky me.”

It’s the same feeling Buch, who turns 85 on Thursday, will get when he makes his sixth appearance at the Penn Relays Saturday in the masters 100-meter dash for runners 80 and older. He doesn’t expect to win, but winning is never really the point anyway.

“When we finish the race, we all hug each other,” Buch said of his fellow runners. “We are here! Lucky us! It’s really amazing.”

Now in his 51st year of teaching at La Salle, or, as he likes to say, his 102nd semester (“it sounds more impressive”), Buch has been a finance professor for so long that he’s seen many of his former students retire from successful careers.

But he has no plans of retiring his career — or his running shoes — anytime soon.

“As long as I’m healthy, I’m going to keep teaching and I’m going to keep running,” Buch said. “That’s what life is all about, using the head and using the body.”

Tom Peterson, head coach of the track and field and cross-country teams at La Salle, said Buch is a “ball of energy” and a “bit of a legend” around campus who’s always pushing others to never stop.

“He says, ‘I tell these kids, it’s not about reaching retirement, it’s about keeping going,’” Peterson said. “I imagine that’s a trait that’s unique to him and to the other competitors in the masters 100-meter dash.”

Phil Felton, masters coordinator for the Penn Relays, said Buch is usually one of the first people to call him about the relays every year.

“He’s always excited,” Felton said.

Ever since Everett Hosak became the first person to run the Penn Relays at age 100 in 2002, interest in the masters 100-meter dash has skyrocketed, Felton said. It’s one of Penn Relays’ most popular events, drawing large crowds and wide media coverage. Even the Olympic-tier athletes on hand gather at the sidelines to watch the masters compete.

“The crowd goes nuts,” Felton said.

Buch recalled running next to 100-year-old Ida Keeling in the 2016 masters. After the race was over, the 4-foot-6 woman did push-ups on the track.

“She was amazing,” he said.

While Buch isn’t the oldest participant in the masters 100-meter dash this year — he will have competition from at least one runner who is 100 — he does believe there’s something that sets him apart from the pack.

“I’m positive I’m the only one still working full time, so I have to finish healthy because, quite often, two days later, I have to grade finals,” he said.

A native of Israel, Buch received his undergraduate degree in agriculture from The Hebrew University of Jerusalem before coming to get his MBA in Philadelphia, where he had distant relatives.

While attending grad school at Temple University, Buch met and married his first wife, with whom he shares two children, and decided to make Philly his home. After the two amicably divorced, Buch married his second wife, Deborah, with whom he has a third child.

After getting his master’s from Temple and his doctorate from the Wharton School at the University of Pennsylvania, Buch managed a small brokerage firm before he began teaching at La Salle in 1971.

He calls his career “a blessed profession” and said there’s nothing quite like having the ability to make an impact on people’s lives. And it’s not just his mind that’s active in class, his body is, too.

“I never yet sat down in a classroom. I walk all over the place,” he said. “It’s like surround sound, they have to pay attention.”

About the time he turned 50, Buch got into racquetball. In his 60s he picked up tennis, a game he still plays twice a week.

In 2015, Buch was playing a game of tennis when another player commented on his speed on the court and suggested he enter the Penn Relays masters 100-meter dash, then for competitors 75 and older.

But Buch, then 78, needed a timed record to get in and the last time he’d run the 100-meter dash was in 1954, when he was a kid in Israel. His high school gym teacher lived next door and would wake him at 5:30 a.m. every morning to run barefoot on the sand dunes at the beach.

Buch went to Peterson, La Salle’s track coach, and asked him to time him and write him a letter of recommendation.

“At first I thought it was a bit wild of a scenario,” Peterson said. “I asked him if he’d ever run before and what made him think he could do it. He told me he’s the fastest person on the tennis course.”

Peterson timed Buch running the 100-meter dash at La Salle’s track twice, with his fastest time being 18.2 seconds.

“For a 78-year-old, he was blistering fast,” Peterson said.

Peterson wrote the recommendation letter, and eventually, Buch received the call that he was in. That year, because of the popularity of the category, there were two heats in the 75-plus masters division. Buch was placed among the slower group.

As he stood at the starting line at Franklin Field, on the grounds of his alma mater, he was overcome with emotion. And by the time the race ended, Buch was overcome with disbelief, too.

“Thirty yards into the sprint, I was ahead, and I remember saying to myself a word that starts with the letter S; I said, ‘Oh, sh—! I can win this thing,’” he recalled. “My hands go all over the place. I looked to the right, nobody was there. I looked to the left and the guy almost beat me.”

Buch won his heat, coming in at 18.26 seconds. In the stands, his family — and especially his grandkids — went wild.

“I never understood fully what home field advantage is until I ran the relay for the first time,” he said. “The energy in that stadium is mind-boggling.”

Buch has run in every Penn Relays since (the relays were on hiatus the last two years because of COVID-19), and while he never won again, he still looks forward to the event, all the same.

“I just want to finish healthy and hopefully not last,” he said.

In 2016, the Penn Relays added a category for runners 80 and above, which is the group Buch now participates in. He never trains for the relays, except for his regular games of tennis twice a week.

“I think it’s probably the best-case scenario, that the majority of his training is something he enjoys and does a lot,” Peterson said. “Him being able to do that at his age is more about general longevity and fitness than it is about him running 100 meters.”

And when Buch goes back to the classroom, he shares with his students what he’s learned about life and himself on the track.

“I keep telling my students, ‘The first time I ran I was 78 years old, and this is, by far, one of the most profound things I’ve ever done in my life, so you better realize there is a long life and a lot of joy ahead of you,’” he said.