A native of New England, Dr. Brennan earned his bachelor’s degree from UNH, where he played Division 1-AA football before earning his medical degree and advanced training in sports medicine.

As an active duty Army officer/physician/educator, Dr. Brennan earned twenty-one military awards and medals – including the Bronze Star Medal for service as a trauma and family physician in Baghdad, Iraq. He has published multiple book chapters and peer-reviewed journal articles. Dr. Brennan is a two-time Boston Marathon finisher and an Ironman Triathlon World Championship finisher. He is a senior consultant physician to the Ironman Triathlon World Championship and has been the physician in charge of Finish Line Medical Tent B at the Boston Marathon since 2011.