The heart-health metric many people overlook

There’s a popular saying among fitness enthusiasts — “Never miss a leg day.” And there’s good reason cardiologists stand behind it, too.

A 2024 study published in the European Journal of Preventive Cardiology found that people with quadriceps strength had a lower risk of developing heart failure after having had a heart attack. That matters because heart failure is a common complication after a heart attack, affecting up to 30% of patients within the first year.

But before starting to do squats in the name of heart health, experts say there’s an important distinction to make.

“When it comes to heart health, having strong legs may be a good sign, but it does not automatically mean someone has a healthy heart,” says Dr. Burhan Mohamedali, medical director of heart failure at Sharp Chula Vista Medical Center.

“Lower-body strength can tell us a lot about a person’s overall health,” he says. “But the evidence linking leg strength alone to heart health is not as strong as the evidence supporting overall cardiorespiratory fitness.”

The heart-health measure many people overlook

Cardiorespiratory fitness — also called aerobic fitness — refers to how well the heart, lungs and muscles work together during exercise. Research consistently shows it plays a major role in heart health, quality of life and even survival in people living with heart disease.

One important measurement doctors use is called peak VO2, which measures how efficiently the body uses oxygen during physical activity.

Why does that matter? Because two patients can have similar heart test results on paper but feel completely different in their daily lives.

“One person may be able to walk several miles comfortably, while another becomes exhausted walking across a parking lot,” Dr. Mohamedali says. “Even though their heart measurements look similar, their overall health and functional capacity can be very different.”

That’s why cardiologists pay close attention not just to numbers like blood pressure or ejection fraction — the percentage of blood pumped out of the heart to other parts of the body with each beat — but also to how well patients move, walk and tolerate activity.

What standing up from a chair can reveal

In people with heart failure, doctors use a simple assessment called the “timed up and go” test. Patients stand up from a chair, walk a short distance, turn around and sit back down.

It sounds simple, but the test can reveal a lot.

“This test can tell us not only about a patient’s lower-extremity strength, but also balance, mobility, coordination and overall physical conditioning,” says Dr. Mohamedali. “This is where cardiac rehabilitation can be especially important.”

Why cardiac rehabilitation matters

Cardiac rehabilitation is a medically supervised program designed for people recovering from heart attacks, heart failure and other heart conditions. The goal is not just to help patients exercise more, but to help them be active safely and strategically to reach their recovery goals.

A cardiac rehab program typically includes:

• Aerobic exercise, such as walking or cycling

• Strength training

• Balance and mobility exercises

• Endurance training

• Education about heart-healthy strategies across all areas of a patient’s life

Rather than choosing between cardio and strength training, cardiac rehab combines both to improve overall function and quality of life. And the research is clear: It works.

The HF-ACTION trial, which followed more than 2,300 patients with heart failure, found that structured exercise training was associated with fewer hospitalizations and cardiovascular complications, along with improved quality of life.

“We should think about fitness as part of a cardiovascular treatment plan — not simply a lifestyle recommendation,” says Dr. Mohamedali. “Patients are often told to exercise more, but the goal should be to exercise safely, gradually and consistently.”

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