I think I may have found the key: Super Duper Time Management Skills.
Everyday we are bombarded with what I like to call Shit That Absolutely Needs To Get Done, or STANTGD. If we took our time and did everything totally right and perfect, we'd still be working on our Monday list Wednesday of the week after. It always seems like you find one thing you need to do, like vacuum the floor, but before then you need to pick up everything off the floor, but you can't do that because your tables are cluttered with dirty dishes but the dishwasher is already full of dishes etc. ad infinitum. Throw in roller derby, and you're adding in more than just skating time: you're adding in extra loads of laundry (hosiery, pads, swamp socks), travel time, packing for the road...
So. My life requires time for school and school work, actual work that pays the bills, and leisure time so I can keep myself and the people/animals I love happy. I chose to keep roller derby going because let's face it: it's fun, good exercise, and all my friends are involved with it. Unfortunately, I can't be as thoroughly involved as I once was. Previously, I was going out of town at least every 2 weeks reffing other people's games. No more. I have cut that down drastically. As much as I hate to say it, school is more important than roller derby right now. I didn't go back to not make A's, you know?
The key is to prioritize your life, and figure out ways to get things done simultaneously if possible. At my paying job, I have a lot of down time as I wait for PCR to run, or agarose to set, so during that time I read for my World Lit class, or work on drawings for my Graphics class, or work Statics problems. I'm taking 9 hours of school, and then I work for about 31-32 hours per week. By the time I get home around 7pm, feed myself and my pets, and get set up for my homework my brain is kinda fried. Having work-free weekends helps, which is why I'm not going out of town so much anymore- I need those hours to finally run errands and catch up on homework I couldn't finish during the week because I fell asleep at my desk at 9. I'm fortunate that my job isn't really really busy so that I have time to do homework there. I'm also very active on derby forums, and use that time between centrifuge spins to catch up on posts.
To make your life easier, I have modestly devised a very clever and brilliant flowchart to help you plan your day so that you get as much STANTGD accomplished as possible.