In dialysis, a patient crams in 48 hours of blood-cleaning time into a four-hour window. Stanton said the process leaves most of his patients so exhausted that they go home and lie down. But by not exercising, dialysis patients can fall into a tailspin of ill-health and low physical activity.
To motivate people, Stanton said he often tells patients about a study that took professional athletes and enforced a week of bed rest. The goal was to measure how quickly the body and organs weaken from inactivity.
"On average it took six weeks of hard training to get back from one week of bed rest," he said. Then to think of Ireland's lifelong dialysis treatment leading him to a triathlon does more than amaze people familiar with kidney failure.
"Shad would be a very inspirational fellow to most individuals, even those without kidney disease," said Dr. Leslie Spry, spokesperson for the National Kidney Foundation.
Unlike many dialysis patients, who end up with kidney disease from diabetes or high blood pressure, Ireland had a poorly-understood autoimmune condition, membranoproliferative glomerulonephritis or MTGN, that attacked his kidneys.
"My kidney failure started when I was 10 years old," said Ireland. "This all started with a promise I made to myself in the early '90s when I lost my first kidney transplant."
Ireland said he was lying on the couch, weighed 79 pounds and was barely able to move when he was inspired by footage of two women dragging themselves to the finish line of a triathlon. It took nearly a decade, but in 2003 he was healthy enough to start training.
Yet while Ireland biked for awareness for people already on dialysis, he said his main mission is prevention and funding for the people who may be at risk for kidney disease.
"An hour a day, four days a week is what I advocate," Ireland said. "I wasn't an athlete. When I started this I had no athletic background."
Ireland said he rode to the steps of the Capitol, in part, because of the health-care reform debate going on in Congress and the great amount of money spent caring for dialysis patients every year.
Experts estimate that the 500,000 people on dialysis -- a small fraction of the 300 million total polulation of the country -- account for 6 percent of all Medicare costs.
"Dialysis patients are hospitalized three to five times per year. If you look at the base costs, just to walk through the door is $3,500," Ireland said. Since he began exercising, Ireland said he's been hospitalized less often.
"I've been hospitalized twice in eight years," he said, and those saved costs would just be the beginning. Now Ireland is advocating for testing and prevention funding for kidney failure.
"It's not about cutting, it's about reallocating resources," he said.
ABC News' Dan Childs and Lisa Stark contributed to this report