I frequently find analogies between my running and my religion. After all, for a runner, running becomes a type of religious act in and of itself. And if a finish line is heaven for the runner, and the miles and miles of training are the daily grind that the faithful must endure, then sprints, hills, and speed work represent for the runner what confession and penance represents for the believer.
When we grow lazy and complacent in our faith we risk falling into old habits and build up a barrier between us and our ultimate reward. For the faithful, the way to break that barrier and crack out of the old habits is the physical act of confession and penance, however your particular tradition builds those activities. For the runner, breaking out of the tired old repetition of the long distance grinds means you must head to the track and rip off the calluses that have formed and break yourself down to the principal components that make a runner a runner. A runner must shred those long, slow, endurance fibers that allow him to run for miles and miles at a stretch and reawaken those short, quick sprint fibers than propel him down a track even though his lungs are screaming for air and everything is numb. A runner must go into that realm of complete oxygen deprivation and muscle fatigue. A runner must, in effect, break his own will and conform it once again to that of the task at hand, which is to run with abandon and complete lack of desire for self. You must, in effect, die to distance and be reborn to speed. The runner must remember what it is like to be near that point of complete collapse, and at times even beyond that point, and still find the will to stand up and do it all over again. To allow the body to work even after the mind has checked out.
Only then, after the miles of trials, can the distance runner return, once again, to the daily trial of miles.