Background: The early onset of chronic disease is a major health concern facing the nation. Leading health indicators support physical activity to reduce the mortality and morbidity rates among individuals. The college years represent a time of transition and potential for improved adherence to positive health behaviors. As institutions of higher education seek to improve retention through positive health behavior, an increase in attention to physical activity is warranted. Purpose: The purpose of this study was to evaluate the knowledge, engagement and perceptions of the American College of Sports Medicine (ACSM) guidelines for cardiovascular physical activity among university freshmen and seniors. Methods: A cross-sectional study design was used to survey all University of Alabama undergraduate students (N=21,775). A 26-question electronic survey was used to collect data. Results: A total of 877 surveys were returned representing a four percent (4.0%) response rate. The mean knowledge scores were 4.26 (out of possible 8.0). Students engaged in moderate intensity physical activity on less (M=3.73) days per week than recommended by the ACSM. For vigorous intensity physical activity students reported engagement on more (M=4.06) days per week than recommended by the ACSM. Knowledge of physical activity guidelines was a significant predictor of engagement in vigorous intensity physical activity for both freshmen (n=216, p=.040) and seniors (n=211, p=.016). Significant differences (p=.047) by year in school were found with respect to walking activity where freshman walked more often than seniors. Age (p=.012), race (p<.001) and year in school (P=.047) were all significant with respect to moderate intensity physical activity. Males engaged in more vigorous intensity physical activity than females (p=.003). When examining physical among classes, freshman students reported significant differences in engagement to vigorous intensity physical activity based on the constructs of perceived self-efficacy (p<.001) and perceived barriers (p=.006). Seniors reported significant differences in engagement to vigorous intensity physical activity based on perceived benefits (p=.002) and perceived severity (p=.019). Discussion: University freshman and seniors vary in reasons for engagement in physical activity. While knowledge is not synonymous with engagement it does have an impact on a student's overall decision and understanding of the health benefits of physical activity.