Beginning teachers often feel disillusioned and stressed during their first years of teaching. In the present study, we investigated changes in teacher candidates' constructivist beliefs and emotional exhaustion. We assessed 163 German mathematics teacher candidates 3 times: at the beginning of, in the middle of, and after they completed the induction program. The results revealed a statistically significant decrease in constructivist beliefs and an inverted U-shaped change in emotional exhaustion with an increase at the beginning of the induction program and a decrease afterward. We also found that personal (i.e., math enjoyment) and social (i.e., instrumental support from peers and a constructivist-oriented mentor teacher) resources buffered the decrease in constructivist beliefs and the increase in emotional exhaustion.