▶ Watch Video: 80-year-old runner puts spotlight on nonprofit

An 80-year-old doctor is set to run his 45th Marine Corps Marathon, only missing the race twice since first competing in 1977. Dr. Glenn Geelhoed has run more than 170 marathons on all seven continents, but his true passion is saving lives through his nonprofit, Mission to Heal.

Mission to Heal brings medical supplies and training to the most remote corners of the world.

“We have done what we can to help not just to heal the folk that we see immediately by cutting and sewing, but by teaching those skills such that it continues beyond us,” Geelhoed told CBS News.

He said that his medical missions are inspired by his runs.

“The marathon is a good metaphor because it takes discipline, it takes effort, and it takes a commitment,” he said. “That’s what health care is.”

Asked how much longer he plans on running these punishing races, Geelhoed told CBS News, “Until the next one. And the next one and the one after that.”