Research & Discovery
Take a deep breath
Jennifer Weggen, Ph.D., and a team of VCU researchers are putting science behind breath work.
It’s unusual to find poetry in a medical journal, but in 2020, Physical Medicine and Rehabilitation Clinics of North America ran “Ode for Autonomia,” which begins: Stuck, on the hopeless fear superhighway / Fear is the fuel, / our friend for survival.
The poem, which opens the article, “Autonomic Rehabilitation: Adapting to Change,” written by Raouf Gharbo, D.O., is not, as it first appears, a tribute to fear but a call for its defeat. He continues: Anger, the petulant fear / Harness her, knowing autonomic is not automatic / Hope is a process.
Gharbo is an associate professor in the VCU School of Medicine, who practices in VCU Health’s Department of Physical Medicine and Rehabilitation. His poem, and the article, are about the autonomic nervous system, the subconscious network that keeps your heart beating, lungs breathing and blood pressure in balance. It also oversees the body’s rest and recovery state and fight-or-flight survival response. The problem, he says, is we can get stuck in fight or flight, like a car going 80 mph with no off-ramp.
Gharbo believes we can harness this. With deep breathing.
Within the autonomic nervous system are the sympathetic and parasympathetic branches. When you’re resting, the parasympathetic nervous system is in charge; it’s the body’s recovery mode, or what’s sometimes called the “rest and digest response.” If you’re frightened, stressed or threatened, your sympathetic nervous system (aka “fight or flight”) springs to action.
Fight or flight is useful if you’re running from a bear but not as useful if you’re slogging through an inbox clogged with stressful emails from your boss. The problem: Our bodies don’t always know the difference, and we go into sympathetic overload. Some people, like first responders and police officers, work stressful jobs and schedules that disrupt sleep, making it doubly difficult to rest and recover. Others live with medical conditions, like post-traumatic stress disorder, that prevent their bodies from easily accessing their recovery mode.
In sympathetic overload, your heart rate and blood pressure increase, it can be hard to concentrate and think clearly, and you might get a migraine or sleep poorly. If this becomes chronic, you’re at risk for hypertension, diabetes and even heart failure. “You can’t go without recovery mode,” Gharbo says. “You have to learn to shift your physiology.”
Breathing is one of the best ways.
In the lab of James Burch, Ph.D., a professor in the School of Public Health’s Department of Epidemiology, clinical research scientist Jennifer Weggen, Ph.D. (B.S.’14, M.S.’17, Ph.D.’25), and a multidisciplinary team are putting Gharbo’s theories to the test. They’re looking closely at what happens when we consciously sync our heart rate with our breathing — or, as Weggen puts it, “alignment of your heart and your mind” — all with a simple technique of long, slow, evenly paced breaths. “Activating the sympathetic nervous system isn’t bad,” Weggen says. “But we do overuse it.”
The study method is called heart rate variability biofeedback, or HRVB. Heart rate variability is the naturally fluctuating amount of time between heartbeats. Biofeedback is the practice of measuring and visualizing those changes and patterns. The goal of heart rate variability biofeedback, and the breathing process it’s built on, is to create a more resilient autonomic nervous system, one that is more capable of accessing the body’s rest and recovery mode.
As an exercise, let’s access yours.
Sit or lie down comfortably. Close your eyes if you can. We’ll begin with “interoception,” a simple practice of recognizing how your body feels from within. Direct your attention to the bottoms of your feet. Wiggle your toes. Notice any sensation in your legs, maybe the temperature of the air or the feeling of your clothes. How do your hips feel? Maybe they’re sore or tight, or simply comfortable where you’re sitting. Don’t judge how you feel. Simply notice. This kind of “body scanning” will be familiar to anyone who has taken a yoga class or practiced meditation.
Now you’ll establish a breathing pattern: a long, slow breath in for five seconds, followed by a long, slow breath out for five seconds. Your belly, more than your chest, should rise and fall with each breath. This is an exercise of the diaphragm — a dome-shaped muscle underneath the lungs that helps you inhale, by pressing downward toward your abdomen, and exhale, by pressing back up to empty the lungs. This kind of deep “belly” breathing slows your heart rate and stimulates the vagus nerve, which activates the parasympathetic nervous system.
Slideshow
Jennifer Weggen, Ph.D., and writer Emily McCrary in the lab.
Before beginning, researchers gather data from participants, including using a dynamometer to test grip strength, which helps assess cardiovascular function.
Weggen and colleague Bret Brooks portion out biosamples in the lab.
Though you don’t necessarily need a certified technician to learn the practice — anyone can do the same breathing exercise at home — Weggen compares it to working out at the gym. “If you have a personal trainer, you would see progress much faster and much more consistently,” she says. “It’s important to have somebody be able to do this, especially if you’re trying to do more than just relax or destress. If you’re trying to help with major symptoms of a chronic disease, you need a little more intense practice.”
Weggen’s research team is currently testing HRVB among three groups: military veterans living with long-term effects of concussions, first responders and healthcare providers who then train their patients. Study participants are connected to a heart rate monitor, blood pressure reader, respiratory rate tracker, thermometer and sweat monitors, then coached through the breathing process by a member of the Burch lab trained in HRV biofeedback, and their results studied closely.
Each breathing session is about 20 minutes. Outside the lab, participants do the exercise on their own, using wearable devices that track heart rate and respiration and feed information back to the researchers.
All this data collection is the biofeedback part of HRVB. The goal is not to teach participants to shut down survival mode but to respond flexibly to daily stressors. “Your body can do so much for you,” Weggen says, “if you let it.”
“You can’t go without recovery mode,” Gharbo says. “You have to learn to shift your physiology.”
Among combat veterans, specifically those living with long-term effects of concussions (like tinnitus, headaches and sleep problems) Weggen, a Navy veteran, and the team are studying whether HRVB can improve concussion recovery, sleep and the body’s ability to sync the heart, lungs and blood pressure. Their work is funded by a $6 million grant from the Department of Defense that continues through 2028.
The first responders study is looking at the effects of HRVB on sleep, stress, anxiety and depression. In the healthcare providers study, researchers are trying to determine whether heart rate variability biofeedback can be easily democratized. Interventionists trained in HRV biofeedback are training healthcare providers so they can pass the strategy on to their patients. They want to know if those patients see the same benefits as those trained by techs in the lab.
People with some conditions — like fast heart rates, mood disorders and long COVID — might not see the same benefits of deep breathing, Gharbo says, but he still sees the technique as broadly applicable.
“I have to get people to understand the importance of recovery,” he says, speaking from experience. In 2002, Gharbo was admitted to the hospital with atrial fibrillation brought on by extreme stress. It was a wake-up call. A few years later, he heard a cardiologist speak about HRV, and “the rest of my life has been spent trying to figure it out.”
Gharbo sees so much promise in HRVB, he says that when he dies — many years in the future, of course, he’s healthy these days — he wants just five words on his headstone: Autonomic rehabilitation for parasympathetic health.
