Staying active can help protect your heart as you age.

A new study by Johns Hopkins Medicine researchers offers middle-aged Americans hope that they can still improve their heart health.

The study, published in the May 15 edition of the journal Circulation, concluded that increasing physical activity levels over a span of six years in middle age was linked to a significantly decreased risk of heart failure.

But that also means you can’t assume past years of healthy living will protect your heart as you enter old age. The researchers found that six years without physical activity in middle age was linked to an increased risk of heart failure, too.

Heart failure, affecting about 6.5 million U.S. adults, is a chronic condition where the heart doesn’t circulate enough blood to fully meet the body’s needs. It’s the leading cause of hospitalization in adults over 65, according to Johns Hopkins.

“The results are not too surprising given that people that exercise [typically] maintain health longer than individuals that do not exercise,” said Vanderbilt University Medical Center cardiologist, Dr. Deepak Gupta.

Gupta said the report again emphasizes how important physical activity is for good health.

“We would expect that individuals that increase their physical activity lower their future risk of heart failure and these results now provide the supporting scientific evidence,” Gupta told Healthline. “An equally important finding is that individuals who were active initially, but became less active over time, were at increased risk for future heart failure.”

The researchers used data previously gathered from 11,351 participants in the federally-funded Atherosclerosis Risk in Communities (ARIC) study. Participants, with an average age of 60, were recruited from 1987 to 1989 in Forsyth County, North Carolina; Jackson, Mississippi; Minneapolis, Minnesota; and Washington County, Maryland.

They were monitored annually for an average of 19 years for cardiovascular-related disease such as heart attack, stroke, and heart failure.

Plus, at the first and third ARIC study visits — which were six years apart — each participant filled out a questionnaire asking them to evaluate their physical activity levels.

These were categorized as:

  • poor: no exercise
  • intermediate: 1–74 minutes per week of vigorous intensity or 1–149 minutes per week of moderate exercise
  • recommended: at least 75 minutes per week of vigorous intensity or at least 150 minutes per week of moderate intensity

Participants categorized as meeting recommended activity levels at both the first visit and then six years later at the third visit, had the largest decrease of heart failure risk — an overall decrease of 31 percent.

This risk of heart failure also continued to diminish with more activity. It decreased by about 12 percent in participants who increased their physical activity levels from poor to intermediate or recommended, or from intermediate to recommended.

On the other hand, heart failure risk increased by 18 percent in participants who reported decreased physical activity between the first and third visits.

“You’re never too old to start exercising… and the opposite is also true,” said Dr. Richard Josephson, a cardiologist at University Hospitals Health System in Ohio, “that at some point you’re exercising regularly and you stop or cut back, that has negative health consequences.”

The recent study joins a large body of evidence on the link between working out consistently and staying heart healthy.

“Heart failure is among the most common causes of morbidity, particularly among older individuals,” said Gupta. “We are increasingly aware that heart failure can be prevented in some individuals. Maintaining or increasing physical activity in middle age appears to be effective in reducing heart failure risk.”

A related study recently published in The Journal of Physiology found that in an across-sectional examination of 102 people over age 60, a lifelong history of exercise of 2 to 3 times a week resulted in more youthful middle-sized arteries. Those who exercised 4 to 5 times a week also had more youthful large-central arteries.

If you’re concerned about staying heart healthy in middle age,Josephson has some tips for people who want to get in shape.

“In general, start low and go slow,” he said. “This is a marathon — not a sprint.”

Josephson suggested starting off by walking for 5 to 10 minutes a day while incrementally increasing the time or distance every few weeks. When reaching 30 to 45 minutes, increase the intensity by picking up the pace.

“The same approach would be relevant if you’re using exercise equipment in a gym,” he said.

When it comes to cardio-specific health, he recommended setting a goal to exercise at least every other day because some of the beneficial biochemical changes that take place in the body from exercise dissipate after 48 hours.

He said that whether it’s aerobic exercise like walking, cycling, or swimming, or isometric strengthening exercises like weight training, the key to sticking to a program is picking one you enjoy.

“You need to find the type of exercise that you can do — that you want to do,” said Josephson.

Another thing to keep in mind is that while exercising for two hours a day is certainly better than one hour, most of the benefits actually take place within that first hour, he said.

So don’t beat yourself up if you max out at 60 minutes.