We spent last week hiking and fishing 9k-11k ft near Chama, NM. I haven’t been in the gym in a few months and that was all the motivation I needed to tighten up my diet and get back to it. Plan on rucking with our packs when they come in. Son plays HS football and is in decent shape too.
Definitely put weight in your packs and hike, walk on a treadmill jacked up, or a stair machine. Use rice in a doubled garbage bag to add weight and volume to your packs. It’s all about conditioning your body for the weight and cardio. Hiking poles used properly, look at YouTube, help a lot once on the trail and especially off the trail. As far as cloths, layers are essential. I like Kenetrek for boots, but there are other good brands too, just stay in the mountaineering alpine style boot that has good support and is stiff; break them in.
What part of WY are going to?
