Two-time Paralympic gold medalist Heinrich Popow instructed lower-limb amputees in the use of sports prosthetics on Sunday, while advocating for the pure enjoyment of sports -- what he called life's "best medicine."

The German and Japanese Paralympian Atsushi Yamamoto were coaching nine amputees at a three-day running clinic in Urayasu, Chiba Prefecture, near Tokyo. The group put on prosthetics used in sports, with carbon fiber running feet, before moving on to basic exercise drills and relays.

"Concentrate on your own rhythm," Popow told one of the participants. "If you feel comfortable, it's easy."

The event was held by Ottobock Japan, the local arm of a wheelchair and artificial limb manufacturer.

Popow has been holding running clinics around the world, even before bringing down the curtain on his career this summer. He won his first Paralympic gold in the men's 100 meters at the 2012 London Games and topped the podium in the long jump at the Rio de Janeiro Games four years later.

The former Paralympian, who had a transfemoral amputation at age nine due to bone cancer, said using prosthetics for sports does not necessarily mean one has to compete at the Paralympics but is a way to simply improve the quality of one's life.

"For us, people with disabilities, sport is the best medicine, the best rehabilitation," he said. "Maybe (somebody) is using sport prosthetics to make (a better) family life -- that is more important than going to the Paralympics."

Shawn Matheson, a winter Paralympian who travelled from Canada with his wife and two sons, said running again was all about his family.

The 46-year-old has won three medals in ice sledge hockey at five Paralympic Games. He attended the clinic to fulfill his dream of running with his sons for the first time. He did so after the clinic, jogging with them on the field.

"I never thought I'd have the opportunity to do that. It's a simple thing, but it's really a big thing and it brought up some real emotions that I wasn't expecting," Matheson said.

"Just being able to run with your kid, it's a special thing. It was a special experience and that's something I'll never forget."

Through the clinics, which he considers his life work, Popow said he wants to deliver the message to people with disabilities that they can believe in themselves.

"With an amputation, a lot of people tell you what you can't do," said Popow, who encourages people with disabilities to attempt what others might think is impossible. "You have to try it out yourself before believing other people (who say those things)."