just participated in the gyms charity 24 hours of fitness. couldnt do it all due to work commitments(and the fear of death!) but i managed to do 2 pilates classes at 6am/7am saturday(interesting),then 3x 1 hr classes of spinning one after the other at 7/8/9pm,then back in at 4am to do 2 more 1hr spin classes.
a great feeling and an achievement for me after only taking any sort of fitness up 6 weeks or so ago.