Depending on the amount of weight you use and the intensity of the exercise you're doing, weightlifting is an intense form of exercise. While it might seem bad for your heart, lifting weights can actually improve your heart health.
Lifting heavy weights decreases your risk for heart problems and helps lower blood pressure.
Aerobic Exercise and Heart Health
Heart health becomes a concern as you age, particularly if you have a family history of heart attacks. According to an article from the Centers for Disease Control and Prevention (CDC), there are roughly 610,000 deaths from heart disease per year in the United States. It's the leading cause of death for both men and women.
There are a few different heart problems that can lead to a heart attack, but the leading cause is coronary artery disease, according to another CDC article. The coronary arteries send freshly oxygenated blood to the heart, keeping the tissue alive. As plaque builds up, there's less and less blood flow to the heart.
Risk factors for coronary artery disease include smoking, obesity, high blood pressure and high LDL cholesterol. You can lessen your risk by cutting down on fat and sodium in your diet and exercising regularly.
Exercise recommendations for health tend to give more attention to cardiovascular exercise, not weightlifting. For example, the U.S. Department of Health and Human Services recommends 150 to 300 minutes per week of moderate-intensity aerobic exercise. As an alternative, you can do 75 to 150 minutes of vigorous aerobic exercise.
Altogether, the recommendation is to do some form of cardiovascular activity almost every day. At the same time, they recommend at least two days per week of resistance training. Both styles of training benefit the heart.
The more cardiovascular exercise you get, the better your heart gets at pumping blood through the body. It doesn't contract harder, like normal muscles. Instead, it stretches more to fit more blood before it contracts. This is known as stroke volume, explains a December 2015 study published in Comprehensive Physiology.
Thickening of the Heart
Your heart is made of four chambers, advises an article from the Texas Heart Institute. The top two chambers are called the right and left atria (the plural of atrium). These smaller chambers fill with blood. The right atrium fills with blood from your body. The left atrium fills with blood from your lungs. The atria contract to send blood down to your ventricles, the other two chambers in your heart.
The ventricles stretch to receive blood and then push it out, circulating it through your body. The right ventricle pushes blood out to your lungs, where it drops off carbon dioxide and picks up oxygen. This oxygenated blood comes back to your left atrium, goes into your left ventricle and is pushed out to your body.
Your heart is a muscle, but you don't want it to work like your other muscles. When you want to grow your biceps and make them stronger, you lift weights. The more muscle you add to your bicep, the stronger it gets. It also looks nice to have muscle tone.
You don't want your heart muscle to grow. When the heart muscle grows, it's a medical condition called hypertrophic cardiomyopathy. According to an article from the American Heart Association, this happens when the muscle cells get bigger, causing the walls of the heart to thicken. It usually happens to the left ventricle.
More muscle in the heart means less room for your blood. When there's less room for blood, the heart has to work harder. This can cause arrhythmia, chest pain, shortness of breath — and even death, in extreme cases. Unfortunately, many people have this condition and never realize it, according to the article from the AHA.
Weightlifting Heart Problems
The cause of hypertrophic cardiomyopathy is a change in the genes of heart muscle proteins, according to the AHA, but high blood pressure can also be a cause. If you do an intense weightlifting exercise like the squat, your muscles are contracting and pushing blood through your cardiovascular system quickly.
Exercise can spike your blood pressure to 200 or higher, according to an article from Johns Hopkins Medicine. However, that's not the kind of increase in blood pressure that causes heart problems. It's only temporary. In fact, doing five sets of an exercise can lower your blood pressure, according to a June 2015 article published in the Journal of Strength and Conditioning Research.
A different study published in January 2015 in the British Journal of Sports Medicine showed that resistance training decreased blood pressure in people with metabolic syndrome. In other words, you don't have to fear a problem like hypertrophic cardiomyopathy because of the brief increase in blood pressure from weightlifting. In the long run you're actually better off hitting the weights.
There are benefits to resistance training beyond lowering blood pressure. For instance, a June 2018 study published in the British Journal of Sports Medicine showed that resistance training not only decreased blood pressure but decreased fasting insulin and insulin resistance. Both can cause heart problems and increase your risk for diabetes.
Effects of Weightlifting on Cholesterol
There are two types of cholesterol: LDL and HDL. LDL is bad, and can lead to cardiovascular problems over time, explains an article from the American Heart Association. HDL is the good type, and can help you regulate and get rid of LDL cholesterol.
Plaque buildup in your arteries can lead to a heart attack. A risk factor for plaque is high LDL cholesterol. But lifting weights can raise your HDL cholesterol — the "good" kind.
A February 2014 study published in Sports Medicine, which reviewed multiple research studies, found that weight training both decreases LDL cholesterol and raises HDL, making it a heart-healthy activity.
There's even a benefit to weight training after a heart attack, under appropriate medical supervision or guidance. According to an article from Michigan Medicine, you might start lifting weights as part of your recovery process. Resistance training for cardiac patients helps get you back to doing normal daily activities. It's common to lose confidence in your body after a heart attack, notes the article. Weight training can help you regain that confidence.
- Michigan Medicine: "Cardiac Rehabilitation: Weight and Resistance Training"
- Sports Medicine: "Differential Effects of Aerobic Exercise, Resistance Training and Combined Exercise Modalities on Cholesterol and the Lipid Profile: Review, Synthesis and Recommendations"
- American Heart Association: "HDL (Good), LDL (Bad) Cholesterol and Triglycerides"
- British Journal of Sports Medicine: "Effects of Short-Term, Medium-Term and Long-Term Resistance Exercise Training on Cardiometabolic Health Outcomes in Adults: Systematic Review With Meta-Analysis"
- British Journal of Sports Medicine: "Resistance Training Reduces Systolic Blood Pressure in Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomised Controlled Trials"
- Journal of Strength and Conditioning Research: "Influence of Number of Sets on Blood Pressure and Heart Rate Variability After a Strength Training Session"
- Hopkins Medicine: "'Exercise Hypertension' Occurs When Cells Can't 'Relax,' Hopkins Researchers Find"
- American Heart Association: "Hypertrophic Cardiomyopathy"
- Texas Heart Institute: "Heart Anatomy"
- Comprehensive Physiology: "Cardiovascular Adaptations to Exercise Training"
- Health.gov: "Physical Activity Guidelines for Americans, 2nd Edition"
- Centers for Disease Control: "Coronary Artery Disease (CAD)"
- Centers for Disease Control and Prevention: "Heart Disease Facts"