We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
On Wednesdays we usually focus on general conditioning (fitness for life) and rarely on training for specific athletic endeavors. That's for a reason.
However, tough hiking is just an extreme variant of walking. A question might be "If you had three months to prep for a ten-day backpacking hike in Denali, or the Bob Marshall, or the White Mountains, or, like us, mountains in the Highlands, what would you do?"
I should modify that a bit. "What would you do, assuming you had a day job and little free time on weekends?"
I asked an exercise expert friend, a competitive athlete who can do several reps of 300-lb deads, that question. She said, given just an hour daily, the emphasis should be on lower body endurance and intense cardio. She said she would do two days/week of the usual powerlifts, but replace her other exercise routines with an hour of stairmaster with a 20-lb weight vest, and an hour of calisthenics with a 5-10-lb weight vest. She correctly observed that hill/mountain hiking is not mostly about strength but is about stamina, agility, and endurance. A person can be very strong without good endurance (and vice-versa). She said an hour of intervals on the bike would be fine, but an hour walking on treadmill with a 20-30 -lb weight vest at a high incline would be better for the purpose.
She also said that, from her experience, daily 7-hour mountain hiking with packs over 10 days can not really be duplicated in normal life. Best approach, when actually doing the trip, would be two to three days on, alternating with one lighter day for recovery. In fact, that is roughly what our guide had planned for our mixed group - two days hard, then one day lighter, and so on. By day 6, I felt eager to tackle anything. Pumped up and ready to go. Too soon, it was time to go home.
Put he emphasis on breaking in your shoes and preparing your feet. The best exercise to prepare for mountainous hiking is mountainous hiking. But if you live in the lowlands that is not an option. But my money is on your feet causing you problems. Your legs; strength and stamina shouldn't be a problem for a healthy person who is already training/exercising. If you intend to carry a backpack, even a small one start carrying that too while you break in your shoes/prepare your feet for the hike.