Engagement, burnout, and experiences are central concepts for understanding student-athlete adjustment in a dual career (DC) environment. As part of a larger 3-year, lower secondary sports schools pilot project, the aim of this study was to examine student-athletes’ DC adjustment in Finnish lower secondary sports schools at the end of the second academic year. By combining quantitative and qualitative methods, we sought to (a) identify adjustment profiles among student-athletes based on measures of engagement and burnout in school and sport and (b) to extract experiences that describe the distribution of student-athletes in the profiles. A latent profile analysis using questionnaire data from a sample of 217 lower secondary student-athletes (M = 14 years, SD = 0.4 years) revealed three distinct profiles: well-adjusted (n = 122), reasonably functioning (n = 73), and struggling (n = 22). Follow-up interviews with a subsample of 19 student-athletes revealed that occasional physical exhaustion and school-related stress were common adjustment issues for student-athletes in all three profiles. Student-athletes showing the well-adjusted profile reported advanced DC management skills that enabled them to maintain low levels of burnout while engaging extensively in school and sport. Adolescents in the reasonably functioning profile reported difficulties in portioning time and thoughts between school and sport, which caused physical and mental DC taxation. To compensate for insufficient time management strategies, adolescents belonging to the struggling profile had to emancipate time for schoolwork by lowering their sports engagement at the cost of heightened school and sport burnout.