Hike as much as you can where you live, wear your hiking boots and carry some weight in a backpack. It’s always a good idea to build in an extra day at the beginning of your trip to get acclimated. While on the trail, drink at least two liters of water per day while hiking. Take hydration drinks such as Cytomax and carry Gu. Eat regularly and stay away from alcohol during the day. Don’t smoke.