When I'm at the greatest odds with my body, it's usually because I feel my body's betraying me, whether that's been in the past, struggling with my weight and feeling that I couldn't eat what I wanted to eat, or that I couldn't get my body to do what I wanted it to do.
To expect. . . the same service from raw and undisciplined recruits, as from veteran soldiers, is to expect what never did and perhaps never will happen. Men, who are familiarized to danger, meet it without shrinking; whereas troops unused to service often apprehend danger where no danger is.