Strength Training Linked to Lower Heart Disease Risk in Women

Women who consistently strength train showed substantially lower risk of major cardiovascular disease, particularly alongside aerobic activity and reduced sedentary time

Women who lift weights may have a lower risk of major heart disease, especially when combined with aerobic exercise, according to a new study published today in JACC, the flagship journal of the American College of Cardiology. Findings show that heart health is better understood by looking at overall movement habits, rather than focusing on single behaviors alone, and resistance training can result in additional health benefits when incorporated into an active lifestyle.

Cardiovascular disease (CVD) remains the leading cause of death worldwide, making accessible prevention strategies more important than ever. Aerobic activities such as brisk walking, jogging, cycling and swimming are well established to help prevent cardiovascular disease (CVD). Resistance training (RT), also known as strength training, is less established. It involves working muscles against a force, such as body weight, free weights, resistance bands or machines.

Current U.S. guidelines recommend at least two days of RT each week and 150 minutes of moderate-to-vigorous aerobic activity. They also stress limiting sedentary behaviors, including prolonged TV watching, now an independent risk factor for CVD. This study examines how RT influences CVD risk as part of this broader prevention approach.

“Despite its established health benefits, RT is often overlooked as a prevention strategy for CVD, and its impact on CVD risk—especially in middle-aged and older women—remains understudied,” said Dr. Tianyue Zhang, MD, lead study author and scientist at the Harvard T.H. Chan School of Public Health’s Department of Nutrition. “A key question is, how much does it add beyond aerobic activity alone?”

Researchers analyzed a prospective cohort of 117,025 women from the Nurses’ Health Study (NHS) and NHS II with a mean age at baseline of 66.8 years and 48.1 years, respectively. RT was assessed every four years and reported separately for the arms and legs. TV viewing time was the primary measure of sedentary behavior and was assessed as average hours per week spent sitting at home watching TV. The primary outcome was incident major CVD, defined as nonfatal or fatal myocardial infarction (MI), stroke, coronary artery bypass grafting or percutaneous coronary intervention (PCI).

In both cohorts, higher levels of RT were associated with lower risk of major CVD, especially MI, with no significant association for stroke. Women who did two or more hours of RT per week had a 20% lower risk of major CVD and a 44% lower risk of MI compared with women who did none. Each additional hour per week was associated with a 5% lower risk of major CVD and a 14% lower risk of MI. These associations became somewhat weaker after adjusting for BMI and cardiometabolic conditions such as diabetes, high blood pressure and high cholesterol, but they remained clear.

RT even offered additional benefit among women who also did aerobic activity. In this subgroup, women who did RT for two or more hours per week in addition to 150 minutes of aerobic activity per week had a 45% lower risk of MI than those with no physical activity, and associations for major CVD changed slightly. In an integrated analysis of movement patterns that considered RT, aerobic activity and TV viewing time together, women who met all three recommendations had the lowest risks of major CVD, MI and stroke compared with those who met some or none of the recommendations.

“These findings suggest that, within an already active population, RT is associated with additional reductions in CVD risk above and beyond overall aerobic activity,” said Zhang. “Alongside aerobic activity and reductions in sedentary behavior, RT may be an important component of public health strategies for cardiovascular prevention in women.”

Study limitations include reliance on self-reported resistance training data, the potential influence of unmeasured factors and limited participant diversity. Researchers also could not fully separate the effects of the type of RT performed from the overall amount of RT the participants completed.

“We have long encouraged resistance training, and this study provides strong evidence to reinforce that message,” said Harlan M. Krumholz, MD, FACC, Editor-in-Chief of JACC and the Harold H. Hines, Jr Professor at the Yale School of Medicine. “It should be included in a well-rounded health routine to support function and longevity.”