Drink tea! It has been found that there's something in tea - it's not the caffeine - improves concentration and speeds up the learning process. It's even more effective if you're multi-tasking.
Researchers at the University of Northumbria gave students gingko biloba and ginseng and foudn that it significantly improved their concentration and memory, so that might help.
I also remember reading that children learn more easily while they're moving around, so perhaps you could exercise and learn at the same time?