1)Prep your feet. Find a rocky, rooty trail close to home and walk it three times a week in the shoes you plan to thru-hike in. When it starts to feel easy, throw on a weighted pack (see below). Pay attention to foot pain: If it persists for a few hikes, take a break to heal and then try different socks or shoes.
2)Strengthen your ankles. Do a dozen lunges and squats per side twice a week to work your core and ankles. For added balance and strength training, use a Bosu ball ($100). Cheaper alternative: Balance on one foot until your ankle tires, then switch.
3) Get pack ready.Carry a backpack on training hikes to prepare your back, core, and shoulders. Begin with a light load and add 5 pounds every week until you’re at your target trail weight. Extra credit: Carry a weighted pack off the trail, too, when shopping or out on errands.
4) Train your brain.True story: You’re going to encounter bad weather on your thru-hike, so get psyched for it now by going on training hikes when it’s raining or windy. Not only will you get mentally prepared, but you’ll also dial in your layering system.
5) Add elevation. If your training hike isn’t hilly, use a treadmill or stair climber. Start with 2,000 feet of elevation gain spread over two or three workouts, then add 500 feet a week until you get to 4,000.