Anonymous on 7/18/2009 6:21:28 PM:
If you aren't doing it already, you need to get out on a real bike and hit the road or trail. You need to condition your body for spending hours in the saddle. Plus the additional demands of balancing and controlling a bike for long periods. Also you need to practice carrying your supplies, drinking while riding, etc.
If you've already made plans for your average distance per day, try working up to that distance and see how you feel (on the road, not at the gym).
Also anticipate going a little slower on the trail. The trail seems to take a couple miles-per-hour out of your usual on the road traveling speed.
When I did an end-to-end (plus a few extra miles) trip in 7 days, I trained by averaging 125 miles a week on local roads and sometimes the trail. I tried to get in a 50 mile plus ride during the weekend, often times carrying my full load of camping supplies. I also did a couple overnight practice trips.
Best of luck!