Best thing Ive done to keep hunting when most friends my age have hung it up is to lift weights that target the large muscle groups. I don't lift the big amounts that some here do. Squats and deadlifts top out at just over 200 but that is enough for me. Anymore and the back starts to act up. Also they are an excellent cardio workout if you don't spend a lot of time sitting around. Not sure one has to really do more with weights other than squats, dead lifts, bent over rows combined with some bench press and chinups/pullups.
Throw in some extra cardio and you should be good to go for the hunting most of us do providing your health stays with you.
