Women gain more cardiac benefit from less when it comes to exercise

The current guidelines from the American Heart Association and the American College of Cardiology endorse a one-size-fits-all recommendation that both men and women get 150 to 300 minutes a week of moderate exercise. That’s good advice, but a new study in the Journal of the American College of Cardiology by the Smidt Heart Institute at Cedars-Sinai shows that women get more heart benefits with less effort than men.

In the study of more than 400,000 people, women who did moderate-intensity exercise, like brisk walking, five times a week reduced their risk of premature death by 24 percent, compared to 18 percent for men.

“I thought the study was actually pretty interesting and enlightening,” said Lawrence McAuliffe, MD, FACC, a cardiologist at Cape Cod Healthcare Cardiovascular Center in Hyannis. “What they found out in this study and some others was an across-the-board benefit in the reduction of cardiovascular all-cause death and cardiovascular mortality for both genders. But interestingly, they found that women had a greater reduction in cardiovascular mortality and cardiovascular death compared to men. In addition, they found that women enjoyed the benefit greater than men and also enjoyed the benefit at less duration of exercise.”

The study showed that women got the same 18 percent benefit as men when they exercised 110 minutes while men needed 300 minutes to get that percentage. The additional 6 percent benefit for women occurred when they increased their exercise time to 300 minutes.

Even More Benefit with Strength Training

Strength training conferred an additional benefit as well, especially for women. Women who did strength resistance training twice a week lowered their cardiovascular mortality by 30 percent versus 11 percent in men.

“As opposed to just aerobic activity, strength training either via bands, tubes, machines or free weights conferred additional benefit to them,” Dr. McAuliffe said. “If women could do two and a half hours a week of aerobic activity and have two or more muscle strengthening activities, that was ideal, but they still enjoyed the benefit in just two and a half hours and one strengthening session a week.”

The reason for the gender discrepancy is that research shows that women have less muscle mass and lean body mass than men do but that they have a significantly increased capillary bed, he explained. Capillaries are the smallest vessel in the body. They deliver single red blood cells with oxygen-carrying capacity to the muscles. That means women’s bodies have the ability to deliver more oxygen and blood, percentage-wise, than men, which is what is believed to confer the additional benefit.

Dr. McAuliffe is an enthusiastic proponent of strength resistance training and does it himself. He said it offers so many benefits in addition to mortality risk reduction. The benefits include:

• An improvement in both physical and mental health.
• Stronger bones and joints.
• Increased endurance.
• A reduction in injuries and falls.
• Maintenance of healthy weight because it adds muscle and muscle burns more calories.
• The regulation of healthy blood sugar levels.

Another benefit is that it can delay the natural aging process of the muscles.

“Our 30s is when we have achieved our maximum muscle mass in our lifetime,” Dr. McAuliffe said. “Somewhere in that decade you start to lose muscle, because muscles atrophy over time. It’s just a natural physiological process. So, by exercising and specifically adding on some weight training, you build up muscle mass to negate and delay that process.”

Read more in next week’s Cape Cod Health News about the many health benefits of resistance training, and about a 77-year-old woman who trains regularly.