It may surprise you to know that musicians can't take even a few months' long break without suffering professionally. Remaining in shape for an audition only lasts until the last few days before that particular audition. If you stop practicing for a few months, it takes at least that long to get back into shape. It is a lot like a professional sport that way. Illnesses are career killers, for example. Also, we have new repertoire coming in all the time by new composers-- whole new concertos to learn, new techniques to be hip to, new gear to learn... I can understand that it might look somehow different from the outside, but this is why a musician can't keep doing auditons forever. First, it is expensive and we don't get corporate sponsors like athletes do. It depends on perfect health, and many can't afford to maintain that without a benefactor. It also takes up every minute of your life to stay audition ready for job auditions and jobs themselves--no one can sustain that kind of mental,physical, and psychological stress for too long. But, while we can, men and women seem to handle these pressures equally well.