WOW ..great thread! Got a few things to add. I ran seriously for 20 yrs (USMC) and that included 4 marathons and humping a pack and rifle/machine gun for more miles than I'd like to count. Here is what I learned the hard way.
1. Not all runners need the same running shoes,some need more cushion and many need more support,esp us bigger guys. Use your running shoes for running only and after about 6-8 months of 15+ mile weeks they will be breaking down so replace them (your joints will thank you)Then you can use them for everyday shoes. 30-45 min. three times a week will build your cardio.
2. Hump,hike,walk, with a weighted pack and the boots you will be hunting in (blisters on a hunt suck). Start light,(20#)and work up (bags of cat litter work great). You use the same muscles differently when walking under a load and running. Do hills,bleachers,steps, both up and down, to build strength with stamina. Going down is harder on muscles than up and more likely for injury. The closer to the hunt do more humping than running. You should build up to one long 3 hr+ hike every 2 weeks. Walk 45-50 min,rest/water for 10.-repeat.
3. Two weeks before the hunt scale back the training to light runs and easy walks. This lets your muscles totaly recover and be healthy for when you need them most. Overtraining can really lead to serious injury and put you out of action for 6 months or more.
I drew a western Montana buck tag this year so I'm in the same boat. At 49 it seems to hurt a lot more to get back in shape than I remembered it did.