Active Voice: Is Weightlifting Good for Your Heart? If Yes, How Much Is Enough?
By Duck-chul Lee, Ph.D., FACSM
Duck-chul Lee (D.C. Lee), Ph.D., FACSM, is a physical activity epidemiologist. Dr. Lee earned his Ph.D. from Seoul National University in South Korea. He is an associate professor in the Department of Kinesiology at Iowa State University. His research focuses on the associations and effects of physical activity, fitness and exercise training. Dr. Lee utilizes both traditional and emerging clinical biomarkers in his work. He concentrates his research on chronic disease prevention and longevity using comprehensive epidemiological approaches that include large cohort studies and randomized controlled trials of exercise.
This commentary presents Dr. Lee’s views on the topic of a research article that he and his colleagues had published in the March 2019 issue of Medicine & Science in Sports & Exercise® (MSSE). This study also was the subject of a news story reported in The New York Times last December.
It is well documented that aerobic exercise, such as running, is good for the heart and prevents cardiovascular disease (e.g., heart attack or stroke); thus, it is commonly called “cardio” exercise. In contrast, resistance exercise has been traditionally considered beneficial for improving sports performance in athletes. More recent studies have suggested potential benefits with resistance exercise for type 2 diabetes, bone health and functional capacity in older adults. However, there is still limited evidence to demonstrate whether weightlifting is good for the heart or reduces risks for heart attack or stroke ? major causes of death in the general population.
In our prospective observational study of 12,591 adults (mean age of 47 years), as presented in the March 2019 issue of MSSE, we investigated the associations of resistance exercise with the risks of developing cardiovascular disease (CVD) morbidity and mortality over time. Subjects were part of the cohort in the Aerobics Center Longitudinal Study who completed at least two preventive health exams between 1987 and 2006. We found that even one time (or less than one hour) per week of self-reported resistance exercise was associated with approximately a 40-70 percent reduced risk of developing heart attack, stroke or CVD mortality. Similar results were found whether subjects met the aerobic exercise guidelines or not. This suggests that weightlifting, alone, may be good enough to gain significant CVD risk reduction benefits. However, spending more than an hour a week in resistance exercise did not provide any additional benefits, although there were no indications that more resistance training was harmful. We, however, note a U-shaped dose-response association between CVD risk and incremental increases in time spent resistance training. Similar results were observed in death from any cause.
People may think that they need to spend several hours a week of weightlifting to gain significant health benefits. However, this study confirms again the current physical activity guidelines suggesting that any exercise, resistance exercise in this case, is better than none for health. The question of whether there is a safe upper limit or not is still questionable and needs further investigation.
Another million-dollar, unanswered question is how people make weightlifting part of their busy daily routine and stick with it. Unlike aerobic exercise, like running, that most people can easily do anywhere and without special equipment, situations conducive to resistance exercise are more limited. In this case, health club membership may be more practical and achievable with many options for resistance exercise (e.g., free weights, weight machines, body pump classes). In our previous cross-sectional study, we found people with a health club membership were about 14 times more likely to meet both aerobic and resistance exercise guidelines and had favorable CVD risk factors including lower waist circumference.
Muscle is essential for moving your body (e.g., joints and bones), which is also important when performing aerobic exercise for chronic disease prevention, healthy aging and promoting longevity. Further, muscle is the power plant to burn calories, improve metabolic function and prevent obesity and dyslipidemia (all well-established CVD risk factors). The key factor to improving muscle and strength is resistance exercise, which is still underappreciated.
This study fills an important gap in our knowledge about the benefits of resistance exercise to further reduce risk of heart attack or stroke, beyond the well-documented benefits of aerobic exercise. The findings from this study have important implications for CVD prevention by generating more evidence that supports comprehensive clinical and public health strategies — which also supports ACSM’s mission.