Cycle, swim or run in your 20s, think better in your 40s & 50s: study

Keep fit in your twenties - and cycling is one of the ideal ways to do it - if you want your brain to work better when you get to middle-age. That’s the message of a study in the latest online edition of the journal Neurology.

Keeping your heart healthy by taking part in cardio fitness activities like cycling, running or swimming in young adulthood may help reserve your memory and thinking skills in middle age, according to a new study published in the April 2, 2014, online issue of Neurology, the medical journal of the American Academy of Neurology. Middle age was defined as ages 43 to 55.

“Many studies show the benefits to the brain of good heart health,” said study author David R. Jacobs, Jr, PhD, with the University of Minnesota in Minneapolis. “This is one more important study that should remind young adults of the brain health benefits of cardio fitness activities such as running, swimming, biking or cardio fitness classes.”

Test subjects were recruited from the long-term Coronary Artery Risk Development in Young Adults Study, which began in 1985-6.

For this study, 2,747 healthy people with an average age of 25 underwent treadmill tests the first year of the study and then again 20 years later. Cognitive tests taken 25 years after the start of the study measured verbal memory, psychomotor speed (the relationship between thinking skills and physical movement) and executive function.

The treadmill test was similar to a cardiovascular stress test. Participants walked or ran as the speed and incline increased until they could not continue or had symptoms such as shortness of breath.

At the first test, participants lasted an average of 10 minutes on the treadmill. Twenty years later, that number decreased by an average of 2.9 minutes.

The study found a correlation between people’s performance in the first test and their ability in the memory test and psychomotor test 20 years later.

And there’s more good news for those now in their forties who have kept fit for the last two decades. The researchers found that people who had smaller decreases in their time completed on the treadmill test 20 years later were more likely to perform better on the executive function test. Specifically, they were better able to correctly state ink color (for example, for the word “yellow” written in green ink, the correct answer was “green”).

That might not sound very impressive, but it suggests keeping fit helps prevent the development of dementia.

“These changes were significant, and while they may be modest, they were larger than the effect from one year of aging,” Jacobs said.

“Other studies in older individuals have shown that these tests are among the strongest predictors of developing dementia in the future. One study showed that every additional word remembered on the memory test was associated with an 18-percent decrease in the risk of developing dementia after 10 years.”

Dr Jacobs said a concept was emerging of total fitness, incorporating social, physical and mental aspects of health.

“It’s really a total package of how your body is and the linkage of that entire package of performance - that’s related to cognitive function many years later and in mid-life,” he told BBC News.

Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said: “A growing body of evidence suggests exercise may reduce the risk of cognitive decline and dementia, and much research has shown a link between healthy habits in mid-life and better health in old age.

“Investment in research is vital to better understand how we can protect our brains as we age.”