Women who include strength training in their weekly routine may be giving their hearts an extra layer of protection, according to a large new study published in JACC.
Heart disease is the leading cause of death worldwide, and finding simple ways to lower risk is a major goal for doctors and researchers. For many years, health experts have encouraged aerobic exercise such as brisk walking, cycling, swimming, and jogging because these activities strengthen the heart and improve blood circulation.
However, much less has been known about the role of resistance training, also called strength training or weight lifting, particularly in women.
Resistance training includes exercises that make muscles work against a force. This can involve lifting free weights, using resistance bands, exercising on weight machines, or even using body weight during push-ups and squats.
Besides building stronger muscles and bones, resistance training can improve balance, help people stay independent as they age, and support a healthy body weight.
Researchers from the Harvard T.H. Chan School of Public Health wanted to find out whether strength training provides extra heart benefits beyond regular aerobic exercise.
They analyzed information from 117,025 women who took part in the long-running Nurses’ Health Study and Nurses’ Health Study II. These studies have followed the health of healthcare professionals for many years and have become valuable sources of information about disease prevention.
Participants regularly reported how much resistance training they performed, how much aerobic exercise they completed, and how much time they spent sitting and watching television. The researchers then tracked major cardiovascular events, including heart attack, stroke, and procedures used to treat blocked heart arteries.
The results showed that women performing at least two hours of resistance training each week had a 20 percent lower risk of major cardiovascular disease and a 44 percent lower risk of heart attack compared with women who did no resistance training. Every additional hour of strength training each week was linked with a further reduction in heart attack risk.
Women who combined resistance training with at least 150 minutes of aerobic exercise each week had the greatest protection. Those who also limited television viewing had the lowest overall risk, suggesting that overall daily movement matters more than focusing on only one healthy habit.
The researchers noted that adjusting for body weight, diabetes, high blood pressure, and high cholesterol slightly reduced the strength of the results, but the overall pattern remained clear. This suggests that resistance training may improve heart health both directly and indirectly through its positive effects on overall health.
The study does have limitations. Exercise levels were self-reported, meaning some participants may not have remembered their activity perfectly. The study also mainly included health professionals, so future research should include more diverse populations. Because this was an observational study, it cannot prove that weight training alone caused the lower risk.
Even so, the findings support current exercise guidelines that recommend combining aerobic exercise with strength training several times each week. Rather than choosing one form of exercise over another, people may gain the greatest benefits by including both as part of an active lifestyle.
Study review and analysis: This very large prospective study provides strong evidence that resistance training is linked with better heart health in women.
Although cause and effect cannot be confirmed, the large number of participants and long follow-up make the findings convincing. Future clinical studies may help determine the ideal amount and type of strength training for protecting the heart.
If you care about heart health, please read studies about the best time to take vitamins to prevent heart disease, and scientists find how COVID-19 damages the heart.
For more health information, please see recent studies about Aspirin linked to higher risk of heart failure, and results showing Blackcurrants could improve artery functions, blood pressure in older people.
Source: Harvard T.H. Chan School of Public Health.
