Physical activity is healthy.
A recent research based on 30 years of data questions the adage Mens sana in corpore sano (a healthy mind in a healthy body) and the value of exercise for brain health and cognition.
Our health and neuroscience researchers published our study of over a quarter million participants a few days following that study. Our findings confirm the cognitive benefits of moderate and intensive physical exercise, fueling an important scientific debate.
Is exercise pointless for cognition?
First research released March 27, 2023. It is a more careful review of 24 meta-analyses of 11,266 healthy persons.
Most of the 24 meta-analyses in this review found that exercise improved cognitive performance, but the authors say the studies were poor. The scientific community’s predisposition to publish only important outcomes and baseline physical activity levels were rarely considered. After these changes, the scientists discovered that exercise’s benefits may be minimal or even less than anticipated in prior meta-analyses.
These findings suggest that public health organisations like the WHO should stop claiming that physical activity improves cognitive health, academic achievement, and executive function, “at least until more reliable scientific evidence accumulates.”
DNA and genetics help
Our second genetic research, released four days later on March 31, 2023, involved approximately 350,000 participants. Our findings show that moderate and strenuous exercise improves cognition.
The two-sample Mendelian randomization approach uses DNA variants at conception to provide this proof.
99.9% of human DNA is identical. DNA is a lengthy chain of nucleotides that differs every 1,000 bricks between these two persons. Thymine, adenine, guanine, and cytosine randomly stacked bricks. Genetic differences can cause cytosine bricks in one person’s DNA and thymine bricks in another.
Our initial sample of 91,084 participants identified genetic variants related with wrist-worn motion sensor-measured physical activity.
Our second sample of 257,854 adults was utilized to investigate whether genetic variants connected with physical exercise affected cognitive functioning proportionally. This proved that physical exercise causes cognitive function.
Exercise helps
We found that moderate physical exercise (brisk walking, cycling) enhances cognitive performance 1.5 times more than severe physical activity (running, basketball). This shows that exercise enhances cognition without tiredness.
Our results demonstrated no influence on cognitive performance when all physical activity was examined, including sedentary and mild activity. This suggests that cognitive advantages from physical activity require at least moderate intensities.
Our findings support a previous research on BDNF brain protein release and exercise duration and intensity. This protein creates new neurons, connections between them, and blood arteries to nourish them.
This protein, which is produced during exercise, helps explain how physical activity improves cognitive performance. This explanation enhances the findings that exercise improves brain function.
Start now
Several factors may explain the divergence between the meta-analysis review and our genetics-based investigation.
The review solely considers healthy persons, unlike our study. Second, unlike the review, our study classifies light, moderate, and strong physical exercise. Finally, our genetic method analyzes lifelong impacts, while the review is centered on one-month to two-year treatments.
It’s never too late to start exercising, especially because we’re discussing temporal physical exercise. A 2019 study found that beginning late in life had the same health benefits as being active throughout life.
Conclusion: Snap decisions are bad.
Physical activity appears to benefit brain health and cognition. In the present socio-political atmosphere of science skepticism, we should not leap to conclusions based on a single study that contradicts years of research yet uses the same data.
In science, it’s best to wait for further research before changing physical activity requirements. Changing public health messaging requires convergent research from several teams. This article indicates that we are far from that point and that physical exercise improves a wide variety of physical and mental health outcomes.