I haven't signed up for a 100er yet, but I have found the best strategy for multi-days, ultras etc, is drip-drip-drip. So I might say 'I'm getting used to running maras, perhaps I might try a 50k', 'I recovered quicker than I expected from the 50k, maybe I'll try a 50-miler', 'a multi-day event would be good training for my 50 miler' and so forth.
I notice I am the first woman to post here, so perhaps I am giving some key female strategies away, but the above also works for renovations, holidays, clothes, etc.
Edited: 06/05/2012 at 21:01