Aims: The transition from school to university, traineeship or job especially along with moving away from home may lead to unhealthy lifestyle changes in young adults. Thus, we determined the effect of exercise changes during the college years on the development of cardiometabolic risk. Two cohorts of students with considerably varying demands on physical fitness (sport versus dentistry students) were compared. Methodology: 53 randomly selected German male and female sport students (SPS, 20±2 yrs.) and 61 male and female dental students (DES, 21±2 yrs.) were accompanied over their ≈5 years of college. Changes of physical activity and exercise were assessed by dedicated questionnaires and interviews. Metabolic syndrome (MetS)-Z-Score based on the NCEP ATP III definition of the MetS, abdominal fat (%) as assessed by Dual Energy X-Ray Absorptiometry (DXA) and cardiorespiratory fitness (CRF) as assessed by stepwise bicycle ergometry determined the cardiometabolic risk at baseline and 5 year follow-up. Results: 67 percent of the subjects initially included completed the follow-up-assessments. During the 5-year study period physical activity non-significantly increased in both groups (5-10%, P>.15). Indices of exercise increased significantly in the SPS group (P<.001) and decreased significantly (P<.001) in the DES group. Group differences were significant (P≤.047) for all study endpoints with more favorable changes among the SPS group for MetS-Z-Score (-0.25±0.56, P=.367 vs. DES: 1.44±0.78, P<.001), abdominal body fat (1.9±12.8%, P=.539 vs. 10.9±21.8%, P=.004) and CRF (1.6±2.9%, P=.076 vs.-3.3±4.1%, P=.004). Conclusion: Reductions of exercise volume and particularly exercise intensity caused by occupational factors during the college years may be the most prominent risk factor for cardiometabolic diseases in young adults. Compensatory exercise is thus highly relevant and may offset an otherwise unhealthy lifestyle.