Working Out in the Heat Puts Added Stress on Your Heart
When the weather gets hot, even a simple walk can feel harder than usual. You may notice that your heart beats faster, you sweat more, or you get tired sooner. This is because your body has to keep you cool while also supporting your muscles.
As you exercise, your heart rate naturally increases and your blood vessels widen to improve blood flow, pumping oxygen-rich blood to your muscles so they can move and function properly. But when you add heat and humidity into the mix, your heart has even more work to do.
On a hot day, your body tries to cool itself by sending more blood toward your skin. This helps release heat through sweat. At the same time, your muscles still need blood and oxygen to keep moving. Because of this, your heart has to pump faster and harder than it normally would during exercise in cooler temperatures.
Humidity can make things even more difficult. Sweat cools your body when it evaporates from your skin. But when the air is humid, sweat does not evaporate as easily. That means your body stays hotter for longer and your heart continues working overtime.
For some people, this extra strain can become dangerous. “Older adults, people with heart disease, high blood pressure, or diabetes and those who are not used to exercising in the heat may be at a higher risk for heat-related illness,” said Jerry Floro MD, PIH Health cardiologist. Certain medications, including diuretics and some blood pressure medicines, can also affect how your body handles the heat.
One of the biggest concerns of exercising in the heat is dehydration. When you sweat, your body loses water and electrolytes. If you do not replace those fluids, your blood volume can drop. This makes it harder for your heart to pump blood throughout your body. As a result, your heart rate may rise even more and you may start feeling weak, dizzy, or lightheaded.
Tips for Protecting Your Heart When Exercising in the Heat
Here are simple things you can do when exercising in the heat that help protect your heart:
- Drink water before, during and after exercise. If you are sweating heavily for a long time, electrolyte drinks may help replace lost minerals.
- Exercise earlier in the morning or later in the evening when temperatures are cooler.
- Wear lightweight, loose-fitting clothing that allows sweat to evaporate more easily.
- Slow down your pace. Take more breaks when it is hot or humid.
- Avoid exercising in direct sunlight whenever possible.
- Pay attention to how your body feels instead of pushing through discomfort.
It is also important to know the warning signs that something may be wrong. “Stop exercising right away and seek medical attention if you notice chest pain, severe shortness of breath, confusion, fainting or a racing heartbeat that doesn’t slow down,” said Dr. Floro. “Heat exhaustion symptoms like nausea, headache, dizziness and heavy sweating should also be taken seriously.”
Exercise is one of the best things you can do for your heart. Staying active can improve circulation, lower blood pressure, and strengthen your cardiovascular system. But when temperatures rise, it is important to adjust your routine. Slowing down, staying hydrated, and listening to your body can go a long way toward helping you exercise more safely all summer long.
Jerry Floro MD
Jerry Floro MD is a Cardiologist with extensive experience in the areas of cardiovascular disease and interventional cardiology. He strongly advocates the mission of providing compassionate and sensitive medical care to his patients. He embraces new technology and continues to stay abreast of the latest cutting-edge advances in his field. Dr. Floro says it's important to manage all of a patient's care, whether it be non-invasive treatment or interventional surgery. Dr. Floro has been selected for inclusion in the Southern California Super Doctors® by Los Angeles Magazine consecutive times in the last 10 years. In his spare time he's an avid sports lover, especially college football, where he supports his alma mater USC. He received his undergraduate degree from USC and attended medical school at Vanderbilt University. His post-graduate training includes a residency in Internal Medicine at Vanderbilt University, a fellowship in Cardiology at Harbor General-UCLA Medical Center and a fellowship in Cardiac Pacing and Electrophysiology at Long Beach Memorial Medical Center/UC Irvine Medical Center
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