Understanding the factors affecting adaptation processes is a critical issue to accompany individuals involved in demanding environments for helping them fulfilling their optimal functioning and fostering their well-being and life satisfaction. Competitive athletes (especially adolescent athletes in intensive training centers) experience a variety of biological (training sessions), psychological (pressure, win at all cost atmosphere), and social (away from the family) daily demands inherent to the competitive environment. For developing athletes’ optimal functioning (leading to peak performance and well-being), it is therefore critical to favor adaptation to sport performance demands, and to prevent maladaptation (Lazarus, 2000). This challenge calls for a better understanding of howcompetitive athletes adapt to the high demands they face.