Command Sgt. Maj. Nelson Callahan, Joint Task Force-Bravo Command Sgt. Maj., flips a tire as part of a physical training session June 03, 2015, at Soto Cano Air Base, Honduras. A dedicated athlete and mentor, CSM Callahan invites others to join him during this specialized physical training session so they can “lead by example…break a sweat…blast [their] core and…build unit cohesion” (U.S. Air Force photo by Capt. Christopher Love).