Training

Running makes you smarter

December 31, 2009
By Alex Hutchinson

To ring in the New Year, some good news for those who have been exercising (and for those who haven’t, some incentive to get started in 2010!). It’s yet another study linking cardiovascular fitness and intelligence — a familiar topic, but with a few interesting wrinkles.

Swedish researchers examined the records of 1.2 million men who enlisted in military service at the age of 18 between 1950 and 1976, including 268,000 pairs of brothers and 1,432 pairs of identical twins (read the abstract from the Proceedings of the National Academy of Sciences here). The researchers were particularly interested in young adults, because it’s a time when your brain changes rapidly. Intelligence was positively correlated with cardiovascular fitness (as measured by stationary biking), but there was no correlation between intelligence and muscular strength.

In addition, cardiovascular fitness at age 18 often predicted socioeconomic status and educational attainment later in life. When the researchers examined the twin data, they found that environment, not genetics, played the biggest role in these associations.

To be more precise, genetics explained less than 15% of the variation, while environmental influences explained more than 80%. So fitness is, to a large degree, within your control.