Getting bored with your treadmill or exercise bike?

Picking up a couple dumbbells instead of lacing up your running shoes once in a while won’t do your heart any harm, a new study reports.

Splitting the recommended amount of physical activity between aerobic and resistance exercises reduces the risk of heart disease just as well as an aerobic-only workout regimen, researchers found.

“If you’re bored with aerobic exercise and want variety or you have joint pain that makes running long distances difficult, our study shows you can replace half of your aerobic workout with strength training to get the same cardiovascular benefits,” said lead researcher Duck-chul Lee, a professor of kinesiology at Iowa State University.

“The combined workout also offers some other unique health benefits, like improving your muscles,” Lee added in a university news release.

Heart disease is the United States’ top killer, accounting for approximately one in three deaths, researchers said in background notes.

Many studies have shown that aerobic exercise benefits the heart, especially for those with excess weight, but few have compared those results to resistance exercise, the researchers said.

For the study, the team tracked more than 400 people ages 35 to 70 for a year. All were overweight or obese, and all had high blood pressure.

Participants were randomly assigned to one of four groups – resistance exercise only, aerobic exercise only, aerobic and resistance combined or no exercise at all.

Resistance exercises can include weight machines, free weights, elastic resistance bands or even your own body weight, researchers said in background notes. 

Each participant in one of the exercise groups received a tailored workout routine based on their individual fitness levels and health problems. They worked out under supervision for one hour, three times a week for one year.

By the end of the year-long trial, all exercise groups had lost a significant percentage of body fat compared to the no-exercise group.

Every 1% reduction in body fat is associated with a 3% lower risk of high blood pressure, 4% lower risk of elevated cholesterol, and 8% lower risk of metabolic syndrome, the researchers noted.

They also measured four heart disease risk factors at the start, middle and end of the clinical trial — blood pressure, cholesterol, blood sugar and body fat.

The aerobic and the combined workout groups both wound up with a lower score on those heart disease risk factors than the group that didn’t exercise, results show.

Resistance exercise on its own did not provide the same heart health benefits, the researchers noted.

The study also showed one clear benefit of combining aerobic and strength training: The combination group improved in both aerobic fitness and muscular strength, whereas the aerobic-only and resistance-only groups improved only in their area of focus.

The new study was published Jan. 17 in the European Heart Journal.

Lee noted that people can blend aerobic and resistance exercise without taking a bigger bite out of their day.

“One of the most common reasons why people don’t exercise is because they have limited time,” Lee said. “The combined exercise with both cardio and strength training we’re suggesting is not more time-consuming.”

Lee next plans to focus on the “right dose” of resistance exercise for people who are overweight or obese, through another clinical trial.

Physical activity guidelines call for at least 150 minutes each week of moderate intensity aerobic exercise and two sessions of resistance training.

“But these guidelines don’t specify how long those strength training sessions should be to get the health benefits,” Lee noted.

More information

The U.S. Centers for Disease Control and Prevention has more about physical activity.

SOURCE: Iowa State University, news release, Jan. 17, 2024