Now I did the TW last year (2008) and if I can complete it (Every.Single.Mile!) then anyone can! I just rode a lot. Then a LOT more. Then did some spinning classes, then rode home from the spinning classes, then went for a ride in the evning and then rode…… Well, you get the idea. Ride a LOT. 70-80 mile road rides, Meridas, Mayhem, anything.
And learn what your body needs. Mine, for instance, doesn't like certain energy drinks (Gives me a bad tum!) so I experimneted and found one that didn't. Mule bars are all natural and I like them too, for instance.
And you gotta make sure your bike fits PERFECTLY. You gotta love that saddle. Comfort and reliability come first, above EVERYTHING else. I fitted a complete new drivetrain and pads. I never had any sort of mechanical, but there were others on flash bikes failing around me because they didn't prepare their machine properly.