A University of Pittsburgh Medical Center researcher found that people over 65 who walk at a pace of at least 2.5 miles per hour live longer than those who don't.

News of Kanzius's work drew the notice of David Geller, co-director of the University of Pittsburgh Medical Center (UPMC) Liver Cancer Center, who wanted to test the technique in his lab.

Vascular surgeon Jeffrey Isenberg, now at the University of Pittsburgh Medical Center, and colleagues were studying how the gas nitric oxide promotes blood flow.