Well I can't say for sure about post-residency, but during the programs the shift scheduling was consistent all four years (some months you work the day 12-hour shift, other months you work the night 12-hour shift). The only thing that changed was during 3rd and 4th year, the call schedule was a bit more relaxed (after all they have to prep for another round of board exams).

As for burnout, alcoholism is relatively high among many medical specialties: https://www.sciencedaily.com/releases/2016/03/160314111353.h...