MedicalResearch.com Interview with: Deepika Laddu PhD Assistant Professor Department of Physical Therapy College of Applied Health Sciences The University of Illinois at Chicago Chicago, IL 60612  MedicalResearch.com: What is the background for this study? Response: Recent findings in population-based cohort studies on cumulative exercise dose have caused some controversy and debate showing U-shaped trends of association between physical activity and disease risk. Our objective was to better understand this association between physical activity and cardiovascular disease risk from young adulthood to middle age. Given that engagement in physical activity is a continuously evolving behavior throughout life, this study looked at the physical activity trajectories of 3,175 black and white participants in the multicenter, community-based, longitudinal cohort CARDIA study who reported physical activity patterns over 25 years (from 1985 through 2011), and assessed the presence of coronary artery calcification, or CAC, among participants. Unique to this study is the evaluation of long-term exercise patterns from young adulthood into middle age in CARDIA participants. Based on the trajectories (or patterns of change) of physical activity over 25 years, participants were categorized into three distinct trajectory groups: trajectory group one was defined as exercising below the national guidelines (less than 150 minutes a week), group two as meeting the national guidelines for exercise (150 minutes a week), and group three as exercising three-times the national guidelines (more than 450 minutes a week). (more…)