The largest and most detailed study of its kind has concluded that there are links between physical fitness and improved cognitive performance. The investigators also show that improvement ste and the brain is associated with the integrity of white matter.
How does exercise influence the mind?
The authors, who have published their study in the journal Scientific Reports, note that previous research had certain limitations. In some cases, for example, they did not take into account variables that could play an important role.
As an example, researchers could associate low levels of fitness with higher blood pressure. If a study finds that physical fitness has links to cognitive abilities, scientists could argue that it is, in fact, lower blood pressure that increases cognitive power.
The same could apply to other factors that have links to fitness, such as body mass index (BMI), blood glucose levels, and educational status. Also, most studies focus on only one marker of mental performance at a time, such as memory.
A new look at fitness and the brain
The latest experiment, conducted by scientists at the Münster University Hospital (Germany), used a large sample of healthy people, trying to test the links between physical state, brain structure and a wide range of cognitive domains. They also wanted to make sure that they accounted for as many confounding variables as possible. Furthermore, they wanted to understand whether the link between cognitive ability and physical fitness was associated with white matter integrity. (White matter in the brain transmits messages between disparate parts of the brain and coordinates communication throughout the organ.)
For their analysis, the experts used data from the Human Connectome Project, which includes MRI brain scans of 1,206 adults with an average age of 28.8 years. Some of these participants also underwent further testing. In all, 1,204 participants completed a walking test in which they walked as fast as they could for 2 minutes.
A total of 1,187 participants also completed cognitive tests where the volunteers’ memory, reasoning, acuity and judgment, among other parameters, were assessed.
“Surprising” results
Overall, the researchers found that people who performed better on the 2-minute walk test also or did significantly better on all but one of the cognitive tasks. Importantly, this relationship was significant even after controlling for a variety of factors, including BMI, blood pressure, age, educational level, and gender.
The researchers also associated this cognitive improvement with higher levels of physical fitness with improvements in the structural integrity of white matter.
“With the present work, we provide evidence of a positive relationship between physical fitness and white matter microstructure, as well as cognitive performance in a large sample of healthy young adults. We were surprised to see that even in a young population cognitive performance it decreases as fitness levels decline, “explains Jonathan Repple, leader of the work.
“This leads us to believe that a basic level of fitness appears to be an avoidable risk factor for brain health,” he clarifies.
Study limitations?
The current study has many strengths, including the extensive MRI database. However, because the researchers conducted the tests at a specific time, it is not possible to see how physical fitness and cognitive ability change over time. Nor is it possible to say that getting in shape causes an increase in cognitive ability.
Future studies should ask whether increasing an individual’s fitness level also increases cognitive ability.
Also, by design, the current study only investigated healthy young people. How this interaction might be different in older populations or people with mental health problems will require more work. Of course, taking into account previous studies, it is increasingly clear that there are strong links between physical condition and mental agility.
Referencia: White matter microstructure mediates the association between physical fitness and cognition in healthy, young adults. Nils Opel, Stella Martin, Susanne Meinert, Ronny Redlich, Verena Enneking, Maike Richter, Janik Goltermann, Andreas Johnen, Udo Dannlowski & Jonathan Repple. Scientific Reports volume 9, Article number: 12885 (2019) DOI: https://doi.org/10.1038/s41598-019-49301-y
