Gen. David Petraeus has a clear view of leadership, as Maj. John Patrick Gallagher recounts in the book “Leadership Lessons of the White House Fellows” by Charles Garcia. One day when Petraeus was a colonel in the 82nd Airborne Division, he asked his soldiers to name the No. 1 leadership priority of the brigade.

Integrity? Marksmanship? No, the correct answer turned out to be physical fitness. The brigade thought Petraeus was joking, until the colonel began leading his soldiers through an intensive 75-minute exercise drill every morning. And soon his point became clear: The workouts drove the brigade to greater alertness and energy, as well as more pride in themselves and their unit.