Cardiac Metabolism: How Exercise Affects the Heart’s Energy

Have you ever asked yourself, “How does cardiovascular exercise affect the heart’s health?” Medical professionals always push to include regular cardio in your exercise routine for better heart health, but why? Cardiovascular exercise promotes cardiac metabolism, which is excellent for your heart. Keep reading to see how this process works and what it does for your heart.

What Is Cardiac Energy Metabolism?

Cardiac energy metabolism cardiac metabolism) aims to produce chemical energy that allows the heart to function correctly. Your heart uses a lot of energy to circulate blood through your body, so your cardiac system must metabolize energy the way it should. A decrease in cardiac metabolism is linked to a higher risk of heart failure, so treating changes in metabolism rates is vital for heart health.

Cardiac energy is produced in the mitochondria. The mitochondria’s primary function is to generate the energy needed for cardiac metabolism. If the mitochondria don’t have enough of the ideal energy source, they will try to use other sources. However, using different sources will result in less energy for the heart. Since the heart is the most energy-consuming muscle in your body, too little of an energy source can lead to heart failure or other cardiac issues.

What Are the Sources of Energy to Support Cardiac Muscle Metabolism?

It needs the right energy sources to keep your heart working as it should. The sources required for proper cardiac metabolism vary slightly depending on whether you’re at rest or participating in cardio exercise.

Sources at Rest

The primary energy source for your cardiac muscles is adenosine triphosphate (ATP). Between 60 and 70 percent of ATP is used to fuel the contraction of your heart muscles, and the remaining 30 to 40 percent pumps the blood through your heart. While at rest, oxidizing fatty acids and amino acids keeps cardiac metabolism working as it should. 70 to 90 percent of cardiac ATP comes from fatty acids while your heart is at rest. The remaining 10 to 30 percent is comprised of a mix of glucose, lactate, ketone bodies, and other amino acids.

It’s worth noting that research suggests that most heart failure patients show a noticeable reduction in fatty acids in their systems. This decrease leaves the heart without its most important energy source, which means the cardiac metabolism is impaired.

Sources During Exercise

Once you start exercising, the fatty acids and glucose aren’t always enough to keep up with the metabolizing of your cardiac energy. Cardiac energy is depleted quickly, especially when exercising. However, lactate works to pick up the slack during exercise and becomes an important major metabolic substrate while you’re exercising.

What Are the Metabolic Changes that Happen When Cardiovascular Endurance Increases?

Different forms of exercise lead to various metabolic changes in our bodies. Regular cardiovascular exercise increases your cardiovascular endurance. This increases the changes your metabolism sees and can improve various areas of your body. 

Some Metabolic Changes That Come From An Increase In Cardiovascular Endurance Include The Following:

• A larger quantity and size of mitochondria cells
• An increase in the oxidative capacity of your skeletal muscle
• An increase in skeletal muscle myoglobin concentration
• A greater ability to oxidize fatty acids for energy at rest.
• An increase in stores of glycogen

Studies have also shown that increased cardiovascular endurance significantly increases a metabolic hormone called fibroblast growth factor 21 (FGF21). FGF21 plays a role in many significant bodily functions, including regulating fatty acid oxidation in the liver and improving overall metabolic health. Research is still being done on whether FGF21 is directly related to the cardiovascular benefits of exercise.

It is worth noting that to see these changes, one must participate in regular cardiovascular endurance. You should participate in cardiovascular exercise three to five days a week to improve and maintain better endurance. With exercise at an intensity of 60 to 90 percent of HRmax or 50 to 85 percent HRmax reserve for 20 to 60 minutes a day.

Summary

Providing enough of an energy source for your cardiovascular system is crucial to proper cardiac metabolism. Ensure your body gets enough fatty acids and other amino acids to give your heart the energy it needs. Regular cardiac exercise is another excellent way to improve your metabolism’s functions and cardiovascular health because it helps your heart have more energy to consume. Proper diet and exercise will keep your energy-craving heart healthy and working as it should.

Lifestyle Interventions and Risk Factors for Cardiac Metabolism (Cardiac Metabolic Health)

The heart is a muscle, and, like other muscles in the body, it uses chemical energy to power contraction. Adenosine triphosphate (ATP) is the primary source of this energy, and most cardiac ATP (up to 90%) comes from fatty acids, while the remaining ATP comes from lactate, amino acids, ketone bodies, and blood glucose. The process of transforming these into ATP is called cardiac metabolism.

How Does Cardiac Metabolism Work?

Normal cardiac metabolism works as the ATP powers the heart’s contractions and ion pumps. The pool of ATP in the heart is relatively small and can be depleted quickly. Continuous synthesis of ATP is required to maintain the level of ATP necessary for heart operation. However, ATP generation is affected by many factors and is directly affected by both health factors and lifestyle factors.

Risk Factors Affecting Cardiac Metabolic Health

Many people assume that the primary force affecting cardiac health in general is genetics. While genetics do play a role, other risk factors play even larger roles.

Poor Diet

Diet is one of the main factors affecting cardiac metabolism and overall cardiac health. The standard American diet (SAD), which is high in saturated fats and sugar, creates serious deficiencies over time.

Exercise

We tend to think of exercise as something you do when you want to lose weight. And exercise is indeed an essential step in weight loss. However, it does so much more than help your body burn calories. Aerobic and anaerobic exercise both help condition the heart and improve cardiac metabolism.

Stress Management

The modern lifestyle is incredibly stressful. Our bodies are not designed to deal with the level of stress we heap on ourselves, and over time, that can lead to serious health conditions. It’s a major factor in hypertension (high blood pressure), which can lead to heart attack and stroke. It’s also been linked to other behaviors that negatively affect cardiac metabolic health, including smoking, lack of physical activity, heavy drinking, and overeating.

Cardiac Metabolic Factors and Prevention Strategies

The most important step to take in improving your cardiac metabolism is simply realizing that you need to change your lifestyle. Without that realization, no action is possible. Once you’ve realized the need to make changes, you can take a personalized approach to improving cardiometabolic health.

Health Checks

One of the first steps is to have your health checked. Your blood pressure, blood sugar, and cholesterol levels should be checked. Once you know these numbers, you can work with your doctor to create a personalized action plan that helps you move them closer to your ideal range. If you’re already in the ideal range, you can create a plan that helps keep your numbers there.

Establish a Diet Good for Health Health

Another important step is establishing and maintaining a healthy diet. The standard American diet is often deficient in vital nutrients while too heavy in saturated fat and refined sugars/carbs. A balanced diet, such as the Mediterranean diet, offers a good mixture of essential nutrients and healthy fats while also providing plenty of flavor. Diets that are more plant-based than this can offer even more benefits.

Get Physically Active

Want to improve your cardiovascular health? There’s no substitute for exercise. Regular exercise, even as little as 20 minutes three days per week, can dramatically affect cardiac metabolism and overall cardiovascular health. The heart is a muscle – the more you work it, the stronger and more efficient it becomes. It also reduces the risk of cardiovascular disease.

Reduce Alcohol Consumption

Alcohol consumption, even in small amounts, has been linked to a wide range of negative outcomes, including damage to the heart muscle. Previously, researchers suggested that light to moderate drinking had a beneficial impact on heart health through stress reduction. However, the WHO has recently reversed its previous recommendations, stating that even small amounts of alcohol can increase your chance of death from many conditions.

Final Considerations

Many risk factors affect cardiac metabolism. In a healthy heart, ATP is produced efficiently. In an unhealthy heart, it is not produced efficiently, and the body instead relies more on blood glucose oxidation rather than fatty acid utilization. The good news is that cardiac health is not dictated solely by genetics.

Rather, lifestyle factors, including exercise, diet, and stress management techniques, can all have dramatic impacts on cardiometabolic health. This puts the power to make positive change within your hands. From establishing a healthful diet to embarking on a weekly exercise regimen, reducing alcohol consumption, quitting smoking, and watching your blood sugar, cholesterol, and blood pressure, there are plenty of ways to improve your cardiovascular health and reduce the risk of heart disease.

Metabolism Research at the CVRTI

At the Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), there are several labs developing a greater understanding of altered cardiac metabolism.  These scientific insights are also leading to new therapies.  The Shaw Lab , together with the Hong Lab and Dosdall Lab , and in collaboration with the Selzman Lab , Drakos Lab, and Palatinus Labs are developing several new gene therapies for heart failure due to ischemic heart disease which alters the metabolism of the failing hearts.  In addition, the Drakos Lab , Chaudhuri Lab, Franklin Lab , Hong Lab and Shaw Lab are developing new mechanistic insights into the fundamental reasons why heart metabolism is altered during disease.  The CVRTI has the largest group of investigators focused on failing heart muscle and cardiac metabolism in the country.

Ischemic Heart Disease

Ischemic heart disease is a form of heart disease. Usually abbreviated IHD, ischemic heart disease often results from blockages in the arteries of the heart and is marked by the heart not getting sufficient blood flow and oxygen. IHD also affects cardiac metabolism in several ways.

Understanding Ischemic Heart Disease

In ischemic heart disease, the heart is forced to work without sufficient blood flow or oxygen. In most cases, this is caused by plaque buildup within the arteries that feed the heart, which reduces blood flow to heart muscle. However, it can also be caused by a demand for oxygen that exceeds what blood can supply. If the condition is caused by plaque buildup, the complete blocking of an artery by plaque can cause coronary artery disease or a heart attack.

Ischemic heart disease also affects cardiac metabolism and heart function. Ischemic events can change fuel metabolism by causing a switch from lactate uptake to lactate production within the heart. It can also cause a decline in FAs and carbohydrate oxidation and increase glycolysis.

The glucose used for glycolysis comes from two places. First, uptake from the blood. Second, it can also come from the breakdown of myocardial glycogen stores. Over time, this leads to higher proton levels. When combined with increased lactate production, it can cause myocardial ischemia or myocardial injury.

Thankfully, patients suffering from ischemic heart disease can take steps to mitigate their risk and reduce or eliminate the plaques responsible for constricting blood flow.

Symptoms of Ischemic Heart Disease

While some patients may not notice symptoms of ischemic heart disease or changing cardiac metabolism, many do. The most common symptoms include chest pain, particularly after physical activity, dizziness, heart palpitations, shortness of breath, and swollen feet or ankles. If you’re experiencing any of these symptoms, contact your doctor to make an appointment.

Interventions for Ischemic Heart Disease Prevention and Treatment

Understand that any strategy to reduce the risk of heart disease and restore normal cardiac metabolism must be highly personalized. There is no “one-size-fits-all” solution available. Nevertheless, all successful strategies employ at least a few similar tactics, such as the following:

Tobacco Use

Patients should stop all tobacco use. That’s particularly important for smokers but also applies to smokeless tobacco products and may extend to vapes. Smoking cessation aids can be employed to help reduce the stress caused by quitting tobacco use, which in itself can lead to additional negative outcomes.

Underlying Health Conditions

Patients should properly care for any underlying health conditions that may contribute to developing ischemic heart disease and/or irregular cardiac metabolism. Some conditions known for this include high blood pressure, high cholesterol, and diabetes.

Weight Loss

While obesity does not directly affect ischemic heart disease, it increases the risk for a range of diseases that do, including high blood pressure and high cholesterol. Weight loss options vary depending on age and physical condition, and patients should speak with their doctor to determine which would be appropriate for them.

Exercise

Even moderate exercise a few times per week can be enough to change your cardiovascular health dramatically. You don’t even have to do something strenuous, like running. Just getting out for a 20-minute walk a few times per week has a lot of benefits and can make a major difference in all areas of cardiovascular health. However, speak with your doctor before beginning an exercise regimen to ensure it’s safe for your health.

Heart Healthy Diet and Nutrition

Following a healthy diet is one of the most important steps to take to prevent or even begin reversing ischemic heart disease. Such a diet is low in saturated fat and high in fresh fruits, vegetables, and whole grains.

Know Your Numbers

Regularly test and track your cholesterol and blood sugar. Know your ideal levels and work with your care provider to create a strategy that helps you reach those levels.

Heart Disease Study

A study published in the American Journal of Lifestyle Medicine stated, “Daily habits and actions powerfully affect the risk of cardiovascular disease in general, and coronary heart disease, in particular. Regular physical activity, sound nutrition, weight management, and not smoking cigarettes have all been demonstrated to significantly reduce the risk of CVD.”

Fighting Back Against Ischemic Heart Disease and Irregular Cardiac Metabolism

When caught early enough and treated promptly, ischemic heart disease is reversible. However, doing so requires understanding the lifestyle factors that allowed the condition to occur in the first place, coupled with a commitment to changing your life by losing weight, following a healthy diet, exercising, quitting smoking, and managing underlying health conditions.

Investigations Underway at CVRTI

At the Nora Eccles Harrison Cardiovascular Research and Training Institute (CVRTI), there are several labs developing a greater understanding of ischemic heart disease and altered cardiac metabolism.  These scientific insights are also leading to new therapies for both.  The Shaw Lab, together with the Hong Lab and Dosdall Lab , and in collaboration with the Selzman Lab, Drakos Lab, and Palatinus Labs are developing several new gene therapies for heart failure due to ischemic heart disease as well as protecting the metabolism of the failing hearts.  In addition, the Drakos Lab , Chaudhuri Lab , Franklin Lab , Hong Lab and Shaw Lab are developing new mechanistic insights into the fundamental reasons why heart metabolism is altered during disease.  The CVRTI has the largest group of investigators focused on failing heart muscle (ischemic cardiomyopathy) and cardiac metabolism in the country.