Air Force Senior Airman Brandon Stout, 380th Expeditionary Civil Engineer Squadron, does pull-ups during a workout at an undisclosed location in Southwest Asia on Sept. 11, 2013. (Staff Sgt. Joshua J.

In its simplest terms, the pull-up seems pretty basic: hang from a bar, then pull yourself up to it. It’s not complicated, but that sure doesn’t mean that it’s easy. In fact, this bodyweight, no-fancy ...