Dementia, including brain disorders like Alzheimer’s disease, affect millions of people throughout the world. In the US alone, approximately 5.4 million people have Alzheimer’s disease. While dementia itself is irreversible, lifestyle choices can significantly impact the risk. And one study shows that fitness levels today can indicate risk for dementia in the future.

In a recent study, that spanned over 40 years, researchers examined close to 1,500 women. These participants ranged from 38 to 60 years old. The research began in 1968. At the onset of the study, each woman completed an ergometer cycling test.

While cycling, researchers added weight to the bicycle. Then, they measured how long a woman could cycle before becoming fatigued. They divided all participants into three groups: “low fitness”, “medium fitness” and “high fitness”.

The women were evaluated six more time throughout the 44-year period to evaluate dementia onset.

Researchers expected to see high fitness levels connected with a low dementia risk, but according to study author, Helena Hörder, professor at the University of Gothenburg, Sweden, “I was surprised that it was such a strong association between the group with highest fitness ad decreased dementia risk.”

Just how strong is the association? Researchers found that women with the highest cardiovascular fitness had a 88 percent lower risk of dementia.

At the end of the study, 23 percent of women developed dementia, 45 percent of these women were those who had low fitness levels.

While researchers admit that further study is necessary to determine whether these associations are true across larger groups, one thing’s for sure. The strong association between fitness and dementia risk certainly does spur you on to hit the gym.