Never hunted elk but I have plenty of boot prints all over the state of Ak as a guide and fun time. Training, riding a bike is the best training for mountain travel as it simulates the short power strokes of walking up hill. Ride in a high gear or high resistance Vs spinning. Do flights of stairs with your pack on too, up and down for muscle training but can be prone to injury. Hike the mountains with your pack on is best but its not feasible for everyone but if you can get to the hills on the weekends or a few times a month it will build the body. I also recommend a SLOD every two weeks, slow long over distance run or bke to train the body and mind for long stretches of boredom physical output.
If you drink coffee, tea etc stop drinking all caffeine 2 weeks before your trip, all caffeine to include Coke. It takes 2 weeks to drain the body of caffeine, the headache is annoying the first few days. Now in the hills, a cup of coffee works magic. I also use chocolate covered coffee beans, rocket fuel. Amazing what a handful will do when tired.
Get hydrated at least a week before your trip and stay hydrated, sip water every 15-30mins.
Do not eat large meals on the fly as this will take blood from the muscles to digest the food. Eat good early and late, and snack on the fly. I have been on extreme pushes where we ate nothing but packets of Gu on the fly.
Use maps of the area to learn the terrain and make notes. In the hills make notes too.
Take care of the feet, use Degree on them every morning to control sweat, use socks with 50/50 synth wool or 60/40 because they dry quicker, keep shape longer Vs 100% wool.
Elk, not a moose but I suggest to field dress where it lies and not try to manipulate the body. Saw Vs ax, both have merits but I prefer a saw, more efficient and less weight, works on bone and firewood. Stanely sharp tooth works very well for the price and weight.