One of the things that really helps develop both the mental and physical capacity of a 10 minute set is backing off for a little bit. For example, over the last few weeks I've been increasing the amount of time I've been under the bells as well as the number of reps per set I've been doing, last Thursday I dropped way back on the amount of time and reps I've been doing and will increase incrementally again for a few more workouts then drop back again. What I've experienced dropping back these last couple of workouts, is that with fewer reps I've felt good, I've felt that moving to bigger numbers is more do-able and I'm regaining confidence in my potential to achieve my goals.
Take home is keep trying to improve on your numbers one workout to the next, but after a couple weeks back off a little and rebuild from there. There is a ton of really cool sciency articles, papers and books about this topic but if you remember that every few weeks you need to move back a bit to be able to continually move forward!
Remember there is no Charity Bootcamp at the gym this Saturday but please check out and take part in the Franklin Fun Run