NEW YORK (Reuters Life!) - When Jothy Rosenberg was told after losing a leg and part of a lung to cancer that he would not survive, the teenager went to Utah and skied for 100 days straight.
It was followed by swimming, white water rafting, water skiing, and biking.
Now 36 years later, Rosenberg who is healthy and thriving, has founded six start-up tech companies, earned a PhD and become a grandfather.
"Being told I had zero chance of survival created a chip on my shoulder," said Rosenberg, whose new book, "Who Says I Can't," chronicles how he used endurance athletics to build self-esteem, resilience and strength.
"Fitness was crucial," said Rosenberg, an above-the-knee amputee. "I discovered if I focused harder than my able-bodied compatriots, then I could get good as them."
"Self confidence is sort of like trust. It takes a huge amount of work to build up and almost nothing to tear down. Cancer will do it to you, disability will certainly do it to you," he said. "Once you start building it back, you've got a base to build more."
Rosenberg said he never fails to keep up with his workout. He swims about five miles a week, goes to a spin class twice a week and also enjoys cycling.
For the last 17 years he has swum from Alcatraz to San Francisco to raise money for charity, and he works with the non-profit AccessSportAmerica to bring high challenge sports to the disabled.
"These are people that can't walk but if you help them they can play modified soccer in a gym, or row in the water with modified boats," he said.
Some 32.5 million people in the United States are living with severe disabilities, according to the Census Bureau. They represent 12 percent of the population.
Susan P. Howley of the Christopher and Dana Reeve Foundation, which funds cutting-edge research into spinal cord injury, says the disabled get all the exercise benefits that accrue to the able-bodied, and then some.
"Even for people who are paralyzed, exercise is good," Howley said, "As more interventions make their way out into the clinics, patients are going to have to have bones and muscles that are in good shape to take advantage of the treatments."
Janne Kouri has operated NextStep Fitness, a community-based non-profit facility for people with disabilities in Lawndale, California, since 2008. He hopes to open more across the country.
"We are specifically focused on people with disabilities," Kouri said. "We are wheelchair accessible and our staff is trained by doctors from the Reeve Foundation's NeuroRecovery Network."
"I don't think there's anything more important than exercise and fitness for people with disabilities," said Kouri, who suffered a paralyzing injury after diving into a wave.
"Once the body's idle after an injury it starts deteriorating after 24 hours. I personally lost 70 pounds in two weeks," Kouri explained. "You're like a baby after one of these injuries. It's a long battle."
And a costly one.
"Some people can hardly lift their arms and legs, so they need other people's help in order to exercise," he explained.
"In any town there are hundreds of gyms but people with disabilities don't have one," Kouri said. "It's an expensive endeavor. Our goal is to make it affordable."