Objective: The Training Interventions and Genetics of Exercise Response (TIGER) study is an exercise program designed to introduce sedentary college students to regular physical activity and to identify genetic factors that influence response to exercise. Participants: A multiracial/ethnic cohort (N = 1,567; 39% male), age 18 to 35 years, participated in the study. Methods: Subjects underwent 30 weeks of exercise training, 3 days/week, for 40 minutes at 65% to 85% of age- and gender-predicted maximum heart rate reserve. Multiple measures of body size/composition, heart rate, and blood pressure were obtained. Results: A total of 1,567 participants, (39% male), age 18 to 35 years, participated in the TIGER study. The prevalence of overweight/obesity in participants was 48.0%/19.3% in non-Hispanic Whites, 55.3%/24.2% in Hispanic Whites, 54.9%/25.4% in African Americans, and 38.3%/11.3% in Asians. Average within-semester retention was 68%, but overall retention (30 weeks, 2 semesters) was 20%. Conclusions: The TIGER study represents an efficacious strategy for introducing college-aged individuals to regular aerobic exercise. (Contains 2 tables and 2 figures.)