Yes. We strongly disagree with the claim (often repeated on blogs and forums) that you don’t need to physically prepare for a thru-hike. Conventional wisdom says the best training for the trail is the trail itself. In other words, just take it slow in the first two weeks and you will get strong and adapt to the trail's physical demands.
That may be true for a few hikers — like someone under 25 who is not overweight and already active. However people have a way of overestimating their fitness level, and the trail will quickly correct their misconceptions.
Do not underestimate the difficulty of the AT. The Appalachian Trail is nothing like the PCT — the trail rarely levels off and remains at one elevation. It is either going up or down, and it is steep. And while the elevation gain and loss isn’t nearly as dramatic as on the PCT, the steep rockiness of it is very physically demanding. An 1000 foot climb on the AT is much more difficult than a 1000 foot climb on the PCT.
Even if you are young and physically fit with no cardiovascular problems, if you don’t train you are at greater risk for knee injuries, Achilles injuries, and other trip-ending injuries. Every year the hostel at Neel’s Gap (on-trail, just 30 miles from Springer) is filled with hikers tending injuries, waiting to heal and get back on the trail.
For these reasons we recommend that you arrive at the terminus strong, fit, and comfortable carrying your pack.
Despite training physically for the hike, the first two weeks will be difficult on your body. Even people in great shape do not exercise eight hours a day, every day, for weeks at a time. However, that is what a thru-hike is like: unending exercise.
During the first two weeks the body panics — unsure what is happening, it diverts blood from the digestive and other organs to supply muscles. Consequently, you lose your appetite. After a long hard day of hiking, you find that you just can’t finish your dinner. It feels awful, but you have to force yourself to eat.
Around day fourteen you feel as if a switch has been thrown — suddenly your appetite returns (greater than normal too), and you have more stamina. This has happened to our editors on every thru-hike (and thru-paddle) we've undertaken.
So take it slow the first two weeks and give your body time to adjust to the challenge of the trail. Only hike a few miles the first and second day, then add a few more. And if you can, take a break every twenty minutes — it’s a marathon, not a sprint. This is the best strategy for someone starting a long trek, whether it's their first thru-hike or their fifth.
A zero day is a day where you do zero miles on the trail. A nero is a near-zero, typically a brief couple of easy miles before getting into town.
It is crucial to your health and the overall success of your thru-hike that you take a zero day once a week. Even God rested on the seven day. (Supposedly, we weren't there.) Your body needs a rest and without a regular schedule of zero days, you will flame out and the trip will come to an end.
However, what tends to happen is that zero days become work days. Gear is cleaned and repaired, groceries are bought, laundry is washed, et cetera. Thru-hikers consistently report being more tired at the end of a zero day — from running errands — than they are at the end of a normal hiking day. Our editors prefer to nero into a trail town, get chores done that day, and then zero the next day.
Also, if you have plenty of supplies, you can zero at a campsite. We love to do this — spend a day hanging out in camp, reading, watching the lake or river, exploring the hammock or forest or park where we've camped. These are the most relaxing days.