NOTTWIL, Switzerland — The 28-year-old institution responsible for grooming some of the best wheelchair athletes in the world sits on an expansive lakeside campus in this tiny Swiss town, where locals joke that the pigs outnumber the people.

At a training session one afternoon, a goat from the farm next door ambled up to a roadside fence, a bell clattering around its neck. A cow mooed across the way. And from the track, streaked with jagged shadows by an unseasonably potent sun, there came the low rumble of wheels in perpetual motion.

In this monastic setting, Marcel Hug and Manuela Schär were quietly engaged in the near-spiritual pursuit of speed. On Sunday, the two wheelchair racing champions will attempt to defend their titles at the New York City Marathon. If they do, it will extend a remarkable run of Swiss excellence in the sport: Schär has won three major marathons this year alone. Hug has won one and finished second in three others.

They, like almost every other Swiss wheelchair marathoner, have trained for years at the Swiss Paraplegic Center. The facility serves primarily as a hospital, but the campus houses a rehabilitation center, a life services office and an athletic training facility.