Hilary Achauer
Since the 1950s, scientists and doctors have believed that aerobic activity is good for your heart.
For decades physicians have advised their patients that exercise like jogging, walking, cycling and swimming will improve their cardiovascular health. In contrast, deadlifts, squats and presses were thought only to be useful for building muscle, strengthening bones and improving balance.
This was all true – up to a point. While aerobic exercise does improve cardiovascular health, it turns out that lifting weights benefits the heart more than was previously understood, even without aerobic exercise.
A recent study of more than 117,000 women followed for just over 14 years found that women aged 48 to 66 who did two or more hours of resistance training a week had a 20 per cent lower risk of major cardiovascular disease.
The women in that age group also had a 44 per cent lower risk of myocardial infarction, when compared with women who did no strength training.
For every additional hour of strength training the women did, the study found, there was a 5 per cent reduction in cardiovascular disease, says Dr Meagan Wasfy, a sports cardiologist at Mass General Brigham Heart & Vascular Institute in the US.
Similar results have been found in other studies that have included men and women.
“Individuals, as they age, should prioritise strength training and make sure they walk,” says Mark Haykowsky, a cardiovascular exercise physiologist and professor at the University of Alberta. “But if I had to choose one exercise if you’re 60 or older,” he says, “Number one is strength training,” because of the benefits to the bones, muscles and heart.
Here’s how strength training can help your heart and how to get the most cardiovascular benefits from weightlifting, according to experts.
Strength training and your heart
Our muscles do more than just stabilise the body and help us lift heavy objects.
“Muscle is not just for strength, it’s actually metabolically active tissue,” says Amanda Paluch, a physical activity researcher and associate professor at the University of Massachusetts Amherst.
When we exercise our muscles, Paluch says, we stimulate that tissue, which improves the functioning of blood vessels, helping them relax and dilate more efficiently.
“When that happens, the heart has to work less hard,” Paluch says, which then lowers blood pressure.
Resistance training, contrary to what many experts once believed, is at least as good as aerobic training at lowering blood pressure, Wasfy says. Building muscle also helps heart health by shifting the body’s composition, not only reducing the amount of fat but potentially decreasing the fat inside muscles, she adds.
Reducing body fat helps improve cardiovascular health by lowering blood pressure and blood glucose levels. Muscles are responsible for clearing the majority of the glucose from the blood.
“They can actually do it without insulin, and not a lot of tissues can do that,” Wasfy says, which means that building muscles can help prevent and treat insulin resistance and diabetes. While the uptake of glucose increases during exercise, the effect persists even at rest, especially as the muscles become more insulin-sensitive over time.
This is why, according to the American Heart Association, adults who strength train have about a 15 per cent reduced risk of all-cause mortality and a 17 per cent lower risk of cardiovascular disease, compared with adults who do no resistance training (though the same study showed similar results in people who did only cardio).
While it appears that strength training can improve VO2 max (your aerobic capacity), it has less of an effect if you are already fit. This means if you regularly exercise and want to maintain or improve aerobic endurance, you’ll need to keep running, cycling or swimming in the mix.
One of the limitations of studying resistance training – and why it’s taken scientists so long to understand its benefit for the heart – is that exercises like squats and bench presses are hard to track with a wearable device. That means scientists must rely on self-reported data.
However, the evidence from high-quality, long-term studies that strength training alone can improve heart health has become so persuasive that in 2023, the American Heart Association updated its position on the importance of such exercise for cardiovascular health.
A workout plan for heart health
When patients ask Wasfy what type of exercise they should do for their cardiovascular health, she recommends combining aerobic activity and resistance training.
“You can definitely improve your heart health with resistance training alone,” Wasfy says, “but you can force multiply that by adding in aerobic activity and low sedentary time.”
Wasfy recommends doing at least two strength-training sessions a week, or about two hours total. Experts agree the specific strength training exercises you do don’t matter, as long as you are working both the upper and lower body and following a program of progressive overload: increasing the difficulty as you get stronger.
“Lift a weight eight to 10 times, and when you can do that eight times easily, increase your weight,” Haykowsky says.
“It is not an all or nothing situation,” Paluch says. She recommends starting with one session a week, as short as 20 minutes. “Starting small and going from nothing to something is where we get the greatest gains.”
The New York Times
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