I have this character - male, young (25 or so), fit but not extremely so. (He's a soldier, but more an officer/Navy type than a Marine, if you follow.) He's recently been through a tough mission, a couple of weeks in the field with very few creature comforts, not enough food in the last few days, and has been in combat at least 3-4 times during that period. When the story's set, though, he's been back to base for a couple of days, had his injuries fixed up (they were fairly superficial to begin with, plus he has access to super-meds) and has presumably had time to sleep and eat recently.
For various reasons he gets upset, and heads down to the gym to try and work things off. So my question is: how many sit-ups, pull-ups etc. would it make sense for this guy to be able to do, and how much lower would that number be when he's not at his physical peak, as above? May be very nitpicky, but on the off chance the story ends up being read by someone who knows about such things, I don't want him to come across as either weak or some kind of super-athlete.