PURPOSE: Peer-based education is commonly used on college campuses to provide health information. Using it to introduce physical activity to ethnically-diverse sedentary students attending an urban commuter college has not been explored. We examined the impact of a 10-week peer-based aerobic-exercise (AE) training program on urban college students’ leisure physical activity behavior. METHODS: Inactive students (N = 23, mean age: 21 ± 2.24 yrs) participated in a 10-week training program consisting of approximately 3 weekly AE sessions. Once-per-week sessions led by a peer-student trainer included a short lecture on exercise’s health benefits followed by 30 mins of AE (55%-65% HRR); participants were instructed to complete 2 other AE sessions independently per week and completed weekly online journals to assess adherence. Pre- and post-training evaluations of AE behavior patterns [International Physical Activity Questionnaire (IPAQ)] were conducted in the weeks prior to and following the exercise program and one month (30-IPAQ) and 90 days (90-IPAQ) after the conclusion of training. Descriptive statistics describing program participation and adherence are presented. Paired-samples t-tests were conducted comparing pre- and post-training cardiovascular fitness. RESULTS: Each week 19.1 ± 1.66 participants attended a peer-led session, training at THR of 142.61 ± 22.88. Participants completed a mean of 8.3 ± 1.26 sessions out of the expected 10. They completed a mean of 2.39 ± 1.95 d·wk-1; 34.85 ± 19.62 min·session-1 independently. Twenty (86.96%) participants completed the 90-IPAQ thus, students’ leisure physical activity analysis included only these 20 participants. Pre-IPAQ data demonstrated that 25% of participants engaged in leisure physical activity at a mean of 164 ± 120 MET-min·wk-1. One month following the training period 60% of participants exercised at a mean of 434.38 ±395.76 MET-min·wk-1; 90-IPAQ data demonstrated 55% of participants continued to engage in leisure physical activity at 488.73 ± 381.33 MET-min·wk-1 on average. There was no significant effect of aerobic training on participants’ cardiovascular fitness level. CONCLUSION: Participation in a peer-led aerobic training program may serve as a gateway to adopting a low level of leisure physical activity by urban college students.