Would you rather have a bodybuilder or marathon runner with you in a combat zone patrol?

Neither...if they've never had any sort of training for combat.

Physical strength and endurance are both equally crucial to warfighting; have been since the dawn of time. However, a seventy-year-old who spent at least twenty years of the first half of their life as a combat infantryman is going to "know" things. He's going to know what it's like to be wet, cold, and tired... but have to keep on going. He's going to know the difference between fifty and two hundred and fifty yards... and how that impacts an engagement. He's going to know how to set up fields of fire, how to outflank, and how to move to contact. Because people like this usually end up doing things in the latter half of their life at least somewhat connected to the first... he's probably going to know how to weld, build, fix a truck, and skin a deer. He's going to be sneaky, practical, and depending on many variables... might not give a d@&n about much.

However... he's going to need some young, dumb, and headstrong people to back him up. Hopefully.. they have the sense to listen to him.

Only because you are asking who I trust more to carry me out of enemy fire - Bodybuilder! I am heavy into weight training and I stand 6'0" @ 230lbs... I need a person that is going to be able to pick me up just as easily as I can pick them up. I tell my guys all the time, if you go down, I can carry you, but if I go down, just hand me ammo and take cover cause you ain't carrying my big ass! That why I love the fact that our PLT medic is the same size as me!

This is where the old school metric of evaluation is so flawed. I’ve had guys run 18 minute 3 miles when I was in the Corps that couldn’t hump their way out of a paper bag. Same held true later I. The Army where I had Soldiers running sub-13 minute 2 miles but the moment weight got put on their backs they were useful as a wet noodle. Then there were the meat head gym rats that could lift a truck once but had zero endurance.

Gotta find a happy medium there. Personally I want someone I know can hump 12 miles with at least 70 pounds on their back and still be a functioning human.