As a Former Marine allow me to give somme energy conservation tips for life in the field
Don't run when you can walk
Don't walk when you can stand
Don't stand when you can sit
Don't sit when you can lie down
Don't lie awak when you can sleep.
When in the field with limited food supply extra exercise is of little benefit, you will get enough movement in the infantry no need to PT unless you are forced to.
When you have the oppurtunnity to eat hot chow or mess hall take severe advantage. Eat the meat and high fat items, build up your reserves.
I wasn't Paleo or primal in the Marine corps but applied these principles. I ate everything in site whenever I was given the oppurtunnity. And I would get back in line until I couldn't eat anymore. I was in the infantry, We moved alot on foot, lived and slept in the weather and fatique and hunger were the standard state of being during field time, and as an athlete Marine the MRE rations were not packed with enough nutrition or energy to sustain our movements in the field.
If you have similar duties you will be tired and hungry, so conserve energy and eat when presented. If you are barracks or base with dining facilities and 8 hours of cot time you have the luxury of adding personal PT to your job.
Integrity is what we do when nobody's watching.