I'm impressed that some of you are even talking about regular imperial centuries. I still get pretty much wiped out by metric ones, and it's time in the saddle that does me in, normally taking about 6 hours, including at least one café break. I've only ever done one imperial century, just to get a monkey off my back, and for days afterwards I felt like I'd been dropped onto an anvil, legs akimbo.
Just so that I'm not that bloke who only ever does the minimum12 qualifying rides every single year, I've thrown in a couple of spare ones this year .... and I've tried to make sure that most of my centuries include some proper hills as well. 3 trips to the Cotswolds, 3 to the Malverns and 2 in the Welsh mountains (The Tumble and the Gospel Pass) so far this year.
Contrary to all the well-intentioned received wisdom on several different threads in this forum, for all the effort, I haven't lost an ounce in weight though! (Still over 20 stone). I can't imagine there are many people my size and weight doing this sort of challenge, so I reckon I'll just carry on doing my thing and claiming everything as veterans' super-heavyweight records.