Wow, can't believe I just woke up to this many replies. Thanks, everyone!
@ Greg -- Since I've never done something like this before, it's hard to say, but I'm guessing that it'll be about 16 to 17 hours hiking and the rest will be sleeping/eating in camp. If this turns out to be inadequate, I may decide to hike a bit longer on days two and three and get a couple hours less sleep that second night. I'm sure it'll make for a more than uncomfortable day three, but if it gets me to my goal it might be the way to go.
@ Andy -- This probably won't be the only post I make on this topic, so feel free to get involved and learn along with me. Maybe you'll think to ask important questions that I wouldn't have.
@ Art -- The trail's highest point of elevation is just over 1200 feet, and except for one 12 mile stretch, it's about as level as you could hope for. This is Massachusetts after all.
That said, I'm well aware that my training's inadequate. I do hike with my day pack weight, which is roughly 5 to 7 lbs depending on whether I take one or two liters of water. This includes my pack, emergency gear, a 100 wt fleece, and a windbreaker.
Throwing in a few more pounds and training with those sounds like a great idea, though. I imagine I'll have to carry a ton of food on this trip, so I might be close to 20 lbs when I start out.
I should be able to start doing a 20 miler per month right away. I might even be able to get two in. I'll start doing that.
@ Eugene -- 40 miles a week...wow. That'll be tough to make happen with my full time job, but I bet I can get up to thirty if I'm creative and efficient with my time. Thanks for throwing out the big numbers, though. I guess it's time to start thinking in those terms.
As far as health and sanity on this trip go...I'm not planning to finish up in great mental or physical shape. I'd like to be free of permanent injuries and broken limbs, though. Since this is a big physical challenge for me, I'm aware that it'll take a lot. That's fine.
Also, as soon as the snow and ice are gone, I'll be doing a lot more running. Right now it's a bit tough. When the snow is deeper, it tends to pack down and I can run on it with my icespikes, but when it's the way it is right now...it's pretty sketchy no matter what I do.
I'd love any tips on diet. I'm not sure what my protein/fat/sugars/carbs intake should be here.
@ David C. -- Yep, definitely planning on suffering here, but in some sick way, that's part of the fun. I like the idea of challenging myself this much.
Any tips on footwear? My current trailrunners are getting worn out, so as I'll be buying a new pair in the next month, I might as well buy what I'm planning on wearing for the big hike, even if it doesn't end up being the same pair. Should I consider special insoles?
@ Art again -- That's pretty much what I was planning for. With six months time, I don't see how I could train enough to average 4 MPH for ten consecutive hours each day, but I think 2.5 for 15 or 16 is possible.
@ David W. -- For the smaller mileage I've done, I've definitely found this is true, so I was banking on the fact that it would work for higher mileage as well. When I first started trail running, even two miles would be painful. After a few weeks, though, my muscles seemed to build up enough to do the trick.
Thanks again, everyone