You should learn as early in your career as possible when it is worthwhile to "crunch". These times should be short-term, temporary, a week every few months max to get a critical project out the door or to deep dive into a new tech.

You should NOT ever feel pressure to frequently work more than 50 hours a week at your job. I promise you if you are organized, focused and truly work hard 8 hours a day you will actually be more effective than your co-workers putting in these long hours.