Built to Last — Dr. Benjamin Levine on Reversing Cardiovascular Aging
The heart is not a machine that simply wears down over time. It’s a living muscle that learns, adapts, and strengthens when challenged. Just like the rest of the body. For Dr. Benjamin Levine, a cardiologist and leading researcher in exercise physiology, that truth has shaped an entire career spent proving that aging doesn’t have to mean decline.
In his conversation with Dr. Rhonda Patrick on FoundMyFitness, Levine broke down decades of research showing that the aging heart can actually reverse much of its stiffness and loss of elasticity through consistent endurance training. “You can’t stop the clock,” he said, “but you can slow the rate at which the sand falls.”
The Deconditioning Experiment
Levine began his career in the early 1980s studying the effects of inactivity. His inspiration came from a landmark NASA experiment in the 1960s that examined what happens to the human body during prolonged bed rest, a model for weightlessness in space.
“After just three weeks of bed rest,” he said, “healthy young men lost as much cardiovascular fitness as if they had aged 30 years.” Their hearts shrank, stroke volume plummeted, and VO₂ max, the measure of how efficiently the body uses oxygen, collapsed.
When those same men were re-tested 30 years later, something extraordinary happened. After six months of endurance training, they regained nearly all of what they had lost from decades of aging. “Exercise reversed the changes of aging better than any drug we know,” Levine said.
The conclusion was simple and powerful: aging itself is not the main culprit. Deconditioning is.
The Heart as a Plastic Organ
The heart, like skeletal muscle, remodels itself in response to stress. Endurance exercise, particularly aerobic training that raises heart rate for extended periods, stretches the left ventricle, increases its filling capacity, and enhances its elasticity.
“In sedentary people, the heart stiffens over time,” Levine explained. “It’s like a leather belt that hasn’t been used in years. You can’t stretch it without cracking it.” But in trained individuals, the heart remains supple. The left ventricle expands more fully with each beat, pumping blood efficiently with less pressure.
That’s what makes long-term aerobic training so protective. It’s not just keeping arteries open, it’s maintaining the mechanical youth of the heart.
Levine calls this adaptation “athlete’s heart,” and he’s spent decades proving that it’s not a pathology but a sign of health. Trained hearts are bigger, slower, and stronger. They move more blood with fewer beats.
The VO₂ Max Equation
If there’s one metric that predicts longevity better than any other, it’s VO₂ max. The body’s ability to take in, transport, and use oxygen during exercise.
“VO₂ max is one of the strongest predictors of mortality we have,” Levine said. “It outperforms cholesterol, blood pressure, and almost every other biomarker.”
Every decade after 30, VO₂ max typically drops about 10 percent in sedentary adults. But in those who train regularly, that decline slows to 3 to 5 percent. Elite endurance athletes can retain the aerobic capacity of someone decades younger.
The reason is straightforward physiology. VO₂ max is the product of three systems working in harmony. The lungs drawing oxygen in, the heart pumping it out, and the muscles using it efficiently. Training improves all three.
When the heart becomes more elastic and the arteries more compliant, blood flows more freely. Mitochondria, the power plants inside cells, multiply allowing muscles to burn fuel more efficiently.
“Every workout is a small stress that forces the system to upgrade,” Levine said. “That’s how you keep the heart young.”
Training for Longevity
Levine’s research has also helped answer a question that confuses many. How much exercise is enough to produce these benefits?
His data suggest that moderate aerobic activity, 150 minutes a week, maintains general health, but to actually reverse cardiovascular aging, you need more structured endurance work.
“The sweet spot seems to be four to five sessions per week, including at least two days that challenge the heart rate,” he said. Those higher-effort sessions, whether running, cycling, rowing, or swimming, trigger the remodeling response that keeps the heart compliant.
He calls this the “Goldilocks zone” of exercise: not too little, not too much. High-intensity training every day can lead to overuse, while too little never stresses the system enough to provoke adaptation. The goal is rhythm. Steady doses of cardiovascular stress followed by recovery.
This rhythm, he argues, is the real fountain of youth.
The Cost of Inactivity
Levine is blunt about what happens when we abandon that rhythm. “The heart is the most trainable organ in the body,” he said, “and also the most de-trainable.” Within days of inactivity, stroke volume drops. Within weeks, blood plasma decreases. Within months, the heart stiffens.
In his lab, even short-term bed rest in young, healthy subjects produces measurable changes in heart size and function. “We see the same signatures of aging appear almost immediately,” he explained.
That’s why he believes exercise shouldn’t be treated as optional. “It’s not a lifestyle choice,” he said. “It’s maintenance.”
The evidence is overwhelming. Physical inactivity increases risk for nearly every major chronic disease. Cardiovascular disease, diabetes, dementia, and even certain cancers. But its first and most visible target is the cardiovascular system.
Strength and Endurance: A Necessary Balance
Levine’s focus is endurance, but he’s quick to clarify that aerobic fitness isn’t the whole picture. “Strength training matters too,” he said. “It preserves muscle, bone, and metabolic function. The combination of both is where the real magic happens.”
He recommends two or three resistance sessions per week in addition to endurance work. Strength training helps maintain lean mass, while aerobic training keeps the vascular system flexible.
“The fittest people we study,” he said, “aren’t marathoners or powerlifters. They’re the ones who mix both. The hybrid athletes who can lift, move, and sustain.”
That balance protects against the full spectrum of aging. Sarcopenia, frailty, insulin resistance, and cardiovascular decline.
The Time Window of Reversal
One of Levine’s most fascinating findings is that there seems to be a “window” in midlife when the heart is most responsive to reversal. In his studies, people who began structured training in their 40s and 50s showed dramatic gains in elasticity and VO₂ max.
“But once you get into your 70s or 80s,” he said, “the heart’s connective tissue becomes less plastic. You can still improve, but the structural reversal is smaller.”
That doesn’t mean it’s too late, only that consistency matters. The earlier you start, the more your heart remembers how to adapt. “It’s just like learning a language,” Levine said. “If you speak it often enough, you stay fluent.”
Exercise as Preventive Medicine
Dr. Levine’s message is simple. If there were a drug that improved cardiovascular elasticity, increased mitochondrial density, enhanced insulin sensitivity, and extended lifespan, everyone would be taking it. That drug exists. It’s called exercise.
“We don’t need a pill,” he said. “We need adherence.”
He even pushes back on the way society talks about “working out.” The term implies something extra, something elective. “Exercise is personal hygiene for the cardiovascular system,” he said. “You don’t shower once and call it done. You keep doing it.”
Hardwired Takeaway
The through line in Levine’s research is optimism. The body you have is not the body you’re stuck with. The heart you train can become younger, more efficient, and more resilient, even decades into adulthood.
Exercise doesn’t just add years to life. It adds capacity to those years. The ability to climb stairs without gasping, to travel without fear, to keep your independence deep into old age.
As Levine put it, “The point isn’t to live forever. It’s to stay capable for as long as you’re alive.”
That’s the essence of being Hardwired. Training the system not just to survive time, but to master it.
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