Fighting a Stiff Heart with Aerobic Exercise

A stiff heart may not sound alarming at first but for many, it’s an early warning sign of a serious cardiac issue known as diastolic dysfunction. This condition affects the heart's ability to relax and fill with blood properly, and it can gradually lead to diastolic heart failure. Fortunately, new evidence shows that one powerful intervention regular aerobic exercise can help turn things around.

Here’s how movement may be your heart’s best medicine.

What Is Diastolic Dysfunction?

Every heartbeat has two phases:

• Systole: when the heart contracts to pump blood out.

• Diastole: when the heart relaxes to refill with blood.

In diastolic dysfunction, the heart muscle becomes stiff and doesn’t relax as it should during the diastolic phase. As a result, the heart doesn't fill completely, which limits the amount of blood it can pump. This can lead to fatigue, shortness of breath, and reduced ability to exercise.

Diastolic dysfunction is especially common among older adults and people with high blood pressure, diabetes, or obesity. Studies suggest that more than 50% of all heart failure cases are diastolic in nature, often called heart failure with preserved ejection fraction (HFpEF).

Why Exercise Matters for a Stiff Heart

When you exercise, your body demands more oxygen, which means your heart needs to pump more blood. A healthy heart accommodates this by both pumping harder and filling faster. But a stiff heart muscle can’t relax quickly enough to fill efficiently, creating a major bottleneck.

This is where aerobic exercise plays a transformative role. Unlike strength training, aerobic activity:

• Encourages healthy stretching of the heart muscle

• Improves blood flow and oxygen delivery

• Enhances the heart’s ability to relax during diastole

The Science Behind It

Multiple clinical studies, including randomized trials, have shown that three to four months of regular aerobic training can:

• Improve exercise tolerance

• Reduce symptoms like breathlessness

• Boost quality of life

• Even reverse some of the heart muscle stiffness that drives diastolic dysfunction

One 2022 meta-analysis found that structured aerobic exercise improved cardiorespiratory fitness in patients with HFpEF by up to 18%, while also decreasing hospitalizations.

Best Types of Aerobic Exercise

To help your heart stay flexible, focus on moderate, sustained activity that gets your heart rate up but still allows you to carry on a conversation.

Examples include:

• Brisk walking

• Cycling

• Swimming

• Jogging

• Low-impact aerobics

• Elliptical workouts

Aim for 30 minutes of aerobic exercise at least five days per week. And always check with your doctor especially if you’ve been diagnosed with any heart condition.

Important Reminder: Stick to Cardio, Not Weights

While strength training has its place in overall health, it’s aerobic activity not resistance training that has been shown to reduce heart muscle stiffness. Lifting heavy weights can raise blood pressure and strain the heart further, which may be counterproductive for those with diastolic dysfunction.

Getting Started Safely

If you’ve been diagnosed with diastolic dysfunction or are showing early signs, don’t wait for symptoms to worsen. Starting an aerobic exercise program now can help you feel better and protect your long-term heart health.

Consider asking your healthcare provider about:

• A cardiac rehabilitation program

• A tailored walking or cycling plan

• Safe ways to monitor your progress

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