Learn to deal with Frustration. Lots of frustration.
Punishment is easy to handle. Effort is easy to handle. Obstacles are easy to handle. Theory is easy to handle. Orders are easy to handle.
When you're starving and the CO tells your platoon to do 10 laps around the mess hall before eating, you smile and do the 10 laps, no problem.
The problem is that doesn't happen. No one tells you're going to do laps. And then you get at the door of the mess, starving and hopeful and eager to drown in a plate of bad food, and the CO tells the platoon to do 1 lap because 02 moved. And then another because 13 had the cup on the wrong hand. Then another because the last lap took too much time. Then another because the platoon leader missed a command because he is tired and nervous and pissed. Then another because the Batallion Commander passed while we were on a lap and the platoon leader didn't order marching pace and salute. Then another because he ordered marching pace and while the CO told us to run. And then you're on your 6th lap, and everyone is pissed at everyone else and thrice as tired as if they would be doing 10 laps clear cut in the first place.
And that's not to say anything about constant conflicting orders. Purposefully conflicting orders, from multipe superiors - and no matter what you do, you're getting punished by all of them.
And then frustration leads to agression (specially when combined with tiredness and pressure), and the whole platoon start eating itself inside out.
Learning to smile at being punished for everything you do and won't do, right and wrong, breathe through shit and take it like a champ is the mindset to victory. Embracing it is the big secret.
Also, as the other hue said, his gymroom stats mean shit. What actually has value is: How fast and far can he run? How much can he hump on a march? How far can he march with wet feet before they become ground meat? I imagine he has pushups, pullups and core strength covered, though.