McMahon leads research assessing whether exercise timing improves nocturnal blood pressure and vascular health outcomes

This research investigates whether the time of day people exercise influences nocturnal blood pressure and vascular function in older adults with hypertension. Hypertension, a condition affecting nearly half of U.S. adults according to the Centers for Disease Control and Prevention, impairs vascular function and increases risk for heart disease, stroke and other adverse cardiovascular events. Building on an emerging field known as chronotherapy the alignment of interventions with the body's internal rhythm this study examines whether scheduling exercise at particular times of day produces greater improvements in 24-hour blood pressure profiles, especially nighttime dipping patterns that are critical to cardiovascular health.

McMahon, an associate professor in the MSU College of Osteopathic Medicine Department of Radiology and primary co-investigator on the project, is part of a multi-disciplinary team led by Michigan State University scholars and funded by a $3 million NIH grant. The team includes Katharine Currie, the principal investigator and assistant professor in the College of Education Department of Kinesiology, as well as experts in cardiology and statistical methods. Together they bring clinical and methodological expertise to a study designed to evaluate real-world, ambulatory blood pressure responses to chronologically targeted exercise interventions.

A central feature of the study is the use of ambulatory blood pressure monitoring worn by participants during daily life to capture continuous 24-hour blood pressure patterns. This approach allows investigators to quantify nighttime blood pressure dipping a physiologic decrease in blood pressure during sleep which has been linked to lower cardiovascular risk. The research will compare how exercise performed at different times affects nocturnal blood pressure and overall vascular function, with the goal of determining whether timing exercise to internal biological rhythms yields superior cardiovascular benefits compared with untimed or conventionally scheduled activity.

The study's multidisciplinary composition strengthens its potential impact: George Abela, chief of cardiology and a professor in the College of Human Medicine, contributes expertise on daily blood pressure rhythms and their connection to acute events like heart attack and stroke; Supratik Rayamajhi adds clinical hypertension management perspective; and Marianne Huebner provides statistical leadership to ensure rigorous evaluation of complex, longitudinal ambulatory data. McMahon's role emphasizes the radiologic and physiological assessment of cardiovascular responses, aligning imaging and functional measures with ambulatory blood pressure findings.

If the study shows that exercise timing materially improves nighttime blood pressure and vascular function, the findings could inform targeted, low-cost interventions for older adults with hypertension and reshape clinical recommendations. Providers could incorporate timing guidance into exercise prescriptions, improving ambulatory blood pressure control and potentially reducing the incidence of cardiovascular events tied to blood pressure rhythms. The study is actively recruiting participants, offering an opportunity for community members to contribute to research that bridges chronobiology, exercise science and cardiovascular medicine under McMahon's collaborative leadership.