As a former bodybuilder, I can tell you that stalls are common. The only definitive answer to stalls is to do something different. Albert Einstein defined insanity as doing the same thing over and over and expecting a different result. Take his advice. Try something different, do that binge day (note: binge doesn't mean eat 4000 calories worth of glazed donuts).

Stalls mean your body has settled into complacency. How do you get out of it? Not sure. But there is one surefire way to never get out of a stall: keep doing the exact same thing. Be a scientist. Use your body as the laboratory. You are your own best nutritionist and trainer.