Denver (CNN) -- A year ago, 42-year-old runner Victor Carlos never thought he'd be excited just to see the starting line. But that was before he almost died. In fact, the father of two girls didn't breathe for a month; a machine pushed oxygen through his body. Now he's training for another marathon. It all began in December with a bad bout of the flu that led to an acute bacterial infection. By the time he checked into the hospital, Carlos was barely hanging on. "We walked into the triage, and his oxygen level was only 57%, and everybody turned a corner," Carlos' wife, Brenda Voglewede, told CNN. Healthy blood oxygen levels are higher than 95%.
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Victor Carlos got the flu, then an acute bacterial infection, then an illness that attacked his lungs
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When he checked into the hospital, his blood oxygen level was at 57%
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Doctors started a procedure known as ECMO that gave Carlos' lungs time to heal
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Carlos took his first breath four weeks later and is now training for a marathon
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