Zab Mosenifar, MD, recently completed his 100th marathon at the age of 70 and he personifies the art of living a long, healthy and fulfilling life. Dr. Mosenifar, professor and executive vice chair of the Department of Medicine at Cedars-Sinai Medical Center in Los Angeles, is addicted to running. Next week he heads to California’s Death Valley, to run in grueling heat that would see most of us wilt in a second. It is the kind of “insane” challenge that motivates the doctor, who still works full-time and says he relishes living a modest life, focussed on his job and running. In this (100th) episode of the Live Long and Master Aging podcast, we discuss Dr. Mosenifar’s 50 miles-per-week regimen, his love of red wine, orchids and a busy life. We also find out why he is a stickler for punctuality; prefers driving in the middle lane; and why he gets a “special pleasure from monotony.”