Exercise has been linked to a variety of advantages for mental health, but new research claims there is “limited evidence” of this direct link between increased physical activity with better cognitive health.
According to research results published in Nature Human Behaviour, there is “inconclusive evidence” that physical activity enhances cognitive function after data from more than 100 individual trials involving over 11,000 “healthy volunteers” was analyzed.
Luis Ciria, the study’s lead researcher and the rest of his team, learned that “After re-analyzing 24 meta analyses of randomized controlled trials, including a sum of 109 primary studies and 11,266 of healthy participants, we found rather inconclusive evidence supporting the existence of a possible cognitive benefit derived from regular practice of physical exercise in healthy populations.”
According to Ciria, a postdoctoral researcher, the findings “suggest” that unless “more trustworthy causal evidence develops,” assertions connecting exercise to increased cognitive function should be handled carefully.
Ciria and his team chose to undertake an umbrella study to examine the data offered in 24 distinct RCTs and discovered that these studies typically have too few participants to analyze properly, may be biased, regularly overlook discrepancies, or produce mixed results.
Ciria writes that “In line with recent accounts, we think that this exponential accumulation of low quality evidence has led to a stagnation rather than advance in this field, hindering discernment of the real existing effect.”
In some studies, the exercise group was compared to a completely inactive group, while in others, it was compared to groups that were just less active in comparison.
As anticipated, significant advantages of the exercise group when compared to the sedentary groups were frequently seen.
In other research, physical activity was found to be significantly beneficial even though the experimental group’s beginning mental performance was worse than the control group’s.
The researchers found minimal improvement in the brains of the healthy people who exercised when they re-evaluated the data keeping these potential biases in mind.
The results of Ciria and his team’s research aim to stimulate a reevaluation of public health policies that support exercise compliance exclusively on the basis of its alleged cognitive advantages.
The study says that “Organizations committed to public health like the World Health Organization or National Institutes of Health currently recommend exercise as a means of maintaining healthy cognitive state, which based on our findings can’t be affirmed.”
Not just Ciria and colleagues, but other academics have questioned the validity of the way these clinical studies are reported as well.
The advantages of the brain and physical activity in healthy people have been consistently validated over the past 50 years by clinical trials, however these studies frequently have limitations.
The studies “range greatly, but they’re often brief,” according to Stephen Rao, director of the Cleveland Clinic’s Schey Center for Cognitive Neuroimaging.
Rao shared via US News and World Report that “Most of the trials are 3-6 months. It is rare to find one that is a year. And then, of course, there are also the measurement of cognition, and that is a problem because that is going to vary from study to study.”
Rao contends that the research by Ciria and his team demonstrates the value of relying on observational studies in addition to clinical trials in order to find conclusive proof that exercise is beneficial to the brain.
Rao went on to add that “You do not really get a chance to know whether exercise is working, because it is such a short duration and if your sample sizes are too small, there is no way that you have enough power to even just detect if there is a positive effect.”
Rao added that studies on animals with shorter lifespans, such as lab mice, show that exercise can increase blood flow as well as neural connections, indicating possible long term benefits for humans as well.
Ciria does not imply that physical activity has no impact on the brain or a person’s health; rather, she suggests that more extensive research be done before institutions advise exercise to enhance one’s mental health and brain function in general.
Ciria concluded that “Engaging in exercise brings not only physical but social benefits as well, as we connect with others by forging social bonds, participating in group activities that give us a sense of belonging, and building some new sources of social support. Above all, we believe in the pleasure of doing anything for its sake. The value of exercising may just lie simply in its enjoyable nature.”
