Strong Legs Equal a Sharp Brain

Did You Know…that a new study shows that sturdy legs support brain health?

It has long been known that strong muscles—especially legs muscles, the largest in the body—serve as indicators of health.  As people grow older, those whose legs are more powerful are more mobile than those with weaker legs.  More intriguing, however, is the fact that those with stronger legs also tend to have more mental acuity.

Studies clearly demonstrate the connections between leg strength and overall health, including brain health.  What is less clear, however, is the role luck plays.  Some people may start out with a genetic advantage.  Others may get an edge from their early home environments.  These factors and more combine to confound experimental results.  That’s where twins come in.

Why Twins Make the Best Research Subjects 

Because twins typically start in the same home environment, and share many (or all, if they’re identical) of their genes, they are incredibly valuable to researchers.  Twins essentially begin life on an even playing field, which means that if one twin’s body… brain… and cognitive abilities diverges dramatically from the other’s, the cause is more likely to come from that twin’s lifestyle.

With that in mind, Claire Steves, a senior lecturer in twin research at King’s College in London, turned her attention to twins and their thighs.  Steves and her colleagues pulled the records for 162 healthy, middle-aged female twin pairs from the TwinUK registry.  The registry includes health and fitness data from thousands of British twins, both identical and not.

Steves and her cohorts looked from twins who had completed memory and cognitive ability tests, as well as assessments of metabolic health and leg strength, ten years prior.  Then they brought the twins into a laboratory to repeat the cognitive tests.  Finally, they compared measures of leg power from a decade ago with shifts in brain function over the intervening years.

Sturdier Legs, Stronger Thinking 

The researchers found that the twins who had the sturdiest legs in the initial tests had the slightest declines in thinking skills.  When they controlled for potential influencing factors such as fatty diets, high blood pressure, and unbalanced blood sugar levels, the correlation held up.  The contrast in thinking skills was most distinct within twin pairs.

If one twin had sturdier legs ten years before, she tended to be a significantly stronger thinker.  On average, the more muscularly powerful twin performed about 18 percent better on the mental exercises than her sister.  Brain imaging scans of the identical twins showed a similar trend.  If one twin began with stronger legs, she showed greater brain volume and fewer “empty spaces in the brain,” than the weaker twin.  In both identical and non-identical twins, studier legs were linked to fitter brains ten years later.

Next Steps  

In order to keep their findings as objective as possible, Dr. Steves and her colleagues focused on muscles, rather than exercise habits.  People’s recollections of how frequently they work out are notoriously undependable.  That said, there was a correlation between self-reported exercise and greater leg strength.

Hopefully future studies can continue to explore this connection.  In the meantime, Dr. Steves says the results of her study suggest that anyone can support and strengthen their brain by building their leg muscles.  “I was quite surprised by the strength of the findings,” Steves said, “because to be quite honest, I am someone who has always in the past prioritized the work of the mind over the work of the body.  This study brings home to me that the brain needs exercise to keep fit.”

There’s no need for you to run out and buy a gym membership, Steves recommends simple ways to strengthen your legs that require no equipment and can be done almost anywhere, such as…


There are many more ways to build leg strength, including simply standing more frequently.