So true.
30-45 minutes 3 times a week of mild cardio (tred-mil, stair stepper, olpitcal, ect) will really help throw in 1 minute of push ups (on your knees to begin with) and 1 minute of crunches 3 times a week will make airsoft easier, and life in general better.
Honestly if your winded standing in line waiting to order your super size combo meal, airsoft might not be the hobby for you. And god knows the Army National Guard aint gonna be in your future.
Anyway. Learning how to wear your gear the right way, (back pack on tight and high, not droopy) evened outload, not hauling around more then needed, ect all help.