The glib-sounding, but basically true answer is: If you're planning to do it every day for 5-6 months, you ease into it, and do it at a level you can maintain f

The glib-sounding, but basically true answer is: If you're planning to do it every day for 5-6 months, you ease into it, and do it at a level you can maintain for the next 5-6 months. And if you're feeling sore, ease back off a bit. Your body will mostly tell you what it needs. The conventional wisdom among thru-hikers is that the only way to get in shape for a hike is to start hiking and get in shape as you do it. This seems to be largely true. In 2010 on the AT, down south, a number of people who started out in good shape from e.g. running, pushed too hard early on, had various health problems and dropped off. People also take far, far more Ibuprofen (I.B. Broken) than they ought to so they can continue pushing out long days. For something like a thru-hike, you adjust your level of exertion to what you can sustain for the time you expect to take, which for practical purposes is "indefinitely" when you're talking about a 5 month walk. The above applies to a "normal", unsupported thru-hike. People shooting for the speed record are a whole different case.