Before I switched to audax riding* I used to love riding the longer distance time-trials that we have in the UK and after doing a couple of 100's and 12-hour TT's I decided to do the final distance of a 24-hour TT. I would have liked to have done a 12-hour earlier in the season but the 24-hour was earlier in the season than our local 12-hour so I just went out and did long day rides at a touristy kind of pace and I also rode every 25-mile and 50-mile TT that i could - usually riding home from the event to get more mileage in. I've never been one for training but targeted the only event on the UK TT calendar (the famous Mersey Roads 24-hour event) and somehow managed to lose about 30lbs in the early Summer and felt in good shape for the event in July. There was never any thoughts of using a TT bike so I used my road bike (lugged 631 tubing) and whilst I had hoped to do 360 miles I finished on a slightly disappointing 345 miles (in context, the winner did 480 miles).
* I actually only rode one season of audax. That was in 2007 so as to qualify for PBP.