Updated

Maintaining good cardiorespiratory fitness as a young adult may be linked to better cognitive skills in middle age, according to new research published in Neurology.

Starting in 1985 to 1986, researchers at the University of Minnesota regularly tested the cardiorespiratory fitness of a cohort of 5,115 participants with an average age of 25. Tests were done every five years, with additional exams at years two and seven. Researchers embarked on this long-term study to better understand how fitness can impact a person’s risk for various chronic diseases later in life.

“We wanted to link what happened early in life with what happened throughout life,” study author David Jacobs, a professor in the school of public health at the University of Minnesota, told FoxNews.com.

In their latest findings, participants – now ages 43 to 55 – who showed the smallest decreases in cardio health over the years, also showed the highest cognitive test results.

For each fitness assessment, participants completed a treadmill test that required them to walk or run at increasing speed and incline intervals, until they could not continue or had symptoms such as shortness of breath.

97 percent of original participants were able to complete the treadmill test. Twenty years later, 2,747 participants were still able to complete the treadmill test.

By year 25 of the study, researchers began implementing cognitive tests. They administered three tests to analyze thinking skills, including recalling a list of words and digit-symbol substitution on a document. A third test, the executive function test, involved correctly stating the color of the ink of a word written in a different color. For example, the word “red” written in blue ink.

“One of the main reasons we looked at [cognitive testing] is because of the epidemic of dementia in our society, but whether the loss of thinking skills we saw in our year 25 is predictive of the people who have [been diagnosed with dementia] is something which needs to be followed,” Jacobs said.

When looking at treadmill and cognitive test results, they found that participants with the smallest decreases in cardiorespiratory fitness over the previous 20 years were more likely to perform better on the cognitive testing, specifically the executive function test.

Their findings are especially important for people who are sedentary— not those who are already very active, Jacobs said.

“It is the old message of living a healthy lifestyle right from early on. It’s freshened up in a way by relating it to a different kind of outcome— a really scary outcome because dementia is now more and more common in our culture,” Jacobs said.

Being active, connecting with one’s community, not smoking and following a good diet are important for long-term health, researchers point out.

The team hopes to continue to administer cognitive exams, as long-term studies allow researchers to better understand potential signs of dementia.

“These studies really take will on the part of investigators and community to continue to fund them…it’s a really important aspect, a specific message about being engaged in life and moving around,” Jacobs said.