An Air Force article from Peterson AFB discusses one of the four pillars of Comprehensive Airman Fitness:

According to Chaplain (Capt.) Joe Watson, the spiritual aspect of an individual is whatever faith or religion they have, or don’t have.
 
“(Spirituality) is part of their life and it means something in their life. They rely on their faith or their God for strength and help,” he said. “There are people who do not have a particular religion or faith or who may not even believe in a god. Some [of them] would say, ‘I still am a spiritual person, I still have spirituality.’ Sometimes it means they hang out in nature and get peaceful there. Or they meditate and relax.”

As the article notes, “spirituality” is difficult to measure, and, in some respects, even articulate.  Still, it remains an important part of the total person concept:  physical, mental, social, and spiritual.

Along with the Army’s Comprehensive Soldier Fitness, the US military is making a concerted effort to address the needs of all of its troops, across the spectrum.