HERO study investigates heart rate variability biofeedback therapy for veterans and service members

By Zoe Marquis. This article was initially published in the 11/11/25 Edition of our Concussion Update newsletter; please consider subscribing.

As part of the HERO study, researchers Raouf Gharbo and James Burchat are studying the effectiveness of heart rate variability (HRV) biofeedback for veterans and service members with persisting symptoms after concussion. The researchers will evaluate the effectiveness of HRV biofeedback in alleviating symptoms such as headaches, fatigue, poor sleep, dizziness, concentration issues, and memory problems. HRV biofeedback involves doing breathing exercises while watching your heart rate in real time on a monitor. Deep breathing activates the vagus nerve, which promotes relaxation, digestion, and recovery. In an article by Olivia Trani published in VCU News, Dr. Gharbo explains, “When people learn this technique, they can use it whenever they need it. It’s not like they need a prescription for it. You already have your diaphragm; you just have to learn how to use it.”

Patients are taught to breathe through their diaphragm in a specific pattern, typically about five seconds in and five seconds out. In response, the patient’s heart rate becomes more variable, with a higher rate during the inhale and a lower rate during the exhale. Participants in the HERO study attend six weekly HRV biofeedback sessions and complete controlled breathing practices twice a day on their own. Researchers will compare this group to a control group that does not engage in HRV biofeedback.