Add another half marathon to the list of things Lt. Cmdr. Justin Legg has overcome.
The retired Navy SEAL competed Sunday in the 13.1-mile Rock 'n' Roll Half-Marathon in Virginia Beach, the latest example of his success in recovering from the leukemia that nearly killed him. Every breath was drawn by a set of lungs from the 19-year-old man who inspires him, even in death.
Legg, who received the double-lung transplant just two years ago, knows a thing or two about endurance.
He spent a decade in the elite military unit and was in Iraq six years ago when he was diagnosed with the dreaded disease. Over the next several years, he endured endless rounds of chemotherapy and radiation treatment. His body rejected a bone marrow transplant, causing the new blood cells to attack his skin, liver, lungs and eyes.
Finally, both of Legg's lungs collapsed and he slipped into a coma in summer 2010. When he awoke, not only did he have to learn to walk all over again, he found out he had only months to live if he didn't get the life-saving transplant.
He did, and eight months later, Legg walked a half-marathon.
Sunday's half marathon, however, held special meaning for Legg. For a long time, he didn't know who was behind the lung donation, as organ donors are kept confidential. Then he got an email that gave renewed focus to his recovery.
"I was just sitting at home playing on my laptop," he said, "and a little message popped up. It said, 'Hi my name is Julie McCarthy, I'm the mother of your lung donor.'"
The relationship that ensued prompted Legg, who now trains with the Leukemia & Lymphoma Society's Team in Training, to raise his goals and redouble his efforts. He took on Sunday's Rock 'n' Roll Half-Marathon in honor of McCarthy's son, Jared McKinley Carter.
Legg completed the race Sunday in a time of 3 hours and 5 minutes, but his larger goal was to inspire people to donate to a fund he set up honoring Carter. If he can raise $50,000, the Society will name a research grant in honor of McKinley.
"Jarred Carter died and in doing so saved my life," Legg wrote recently on his blog. "If we can all come together to raise this money and name a project after him, he will, in turn, be helping to save the lives of so many more."
FoxNews.com's Perry Chiaramonte contributed to this report.