Need a brain boost? Fitness may not be for you!
It is more common than not to hear exercising will provide a range of mental health benefits, but new research suggests there is “little evidence” showing a correlation between improved cognitive health and physical exercise.
Analyzing data from over 100 individual trials involving more than 11,000 “healthy participants” found “inconclusive evidence” that physical exercise improves cognitive ability, according to findings published by Nature Human Behaviour.
“After re-analyzing 24 meta-analyses of RCTs (randomized controlled trials), including a total of 109 primary studies and 11,266 healthy participants, we found inconclusive evidence supporting the existence of a potential cognitive benefit derived from the regular practice of physical exercise in healthy populations,” Lead researcher Luis Ciria and his team found during their analysis.
Ciria, a postdoctoral researcher with the Mind, Brain and Behavior Research Center at the University of Granada in Spain, said his team’s findings “suggest” claims linking exercise to improved cognitive ability should be advised with caution until “more reliable causal evidence accumulates.”
Ciria and his team opted to conduct an umbrella analysis to reevaluate the data presented in 24 different RCTs and found that these trials often have too few participating subjects to evaluate appropriately and may be prone to bias, frequently miss contradictions or mixed findings.
“In line with recent accounts, we believe this exponential accumulation of low-quality evidence has led to stagnation rather than advance in the field, hindering the discernment of the real existing effect,” Ciria wrote.
Some studies compared the exercise group to an utterly inactive group, while others compared it to less active groups.
As expected, considerable benefits were typically detected when the exercise group was compared to the sedentary groups.
Other studies found that physical exercise had a significant benefit when the initial mental performance of the experimental group was lower than that of the control group.
By re-evaluating the data with these possible biases in mind, the researchers found little benefit to the healthy person’s brain because they exercised.
Ciria and his team’s findings aim to prompt a reconsideration of public health policies that promote exercise adherence solely based on its purported cognitive benefits.
“Organizations committed to public health such as the World Health Organization or the National Institutes of Health currently recommend regular exercise as a means to maintain a healthy cognitive state, which based on our findings cannot be affirmed,” Ciria wrote in the study.
Ciria and colleagues are not the only researchers to question how reliable these clinical trials are presented.
Over the past 50 years, consistent clinical trials have supported the benefits of the brain and physical exercise in healthy individuals, but these trials often have their flaws.
Stephen Rao, the director of the Schey Center for Cognitive Neuroimaging at the Cleveland Clinic, said the studies “vary considerably, but they’re usually brief.”
“Most of [the trials] are three to six months. It’s rare to find one that’s a year. And then, of course, there’s also the measurement of cognition, and that’s a problem because that’s going to vary from study to study,” Rao told US News & World Report.
Rao suggests that the research found by Ciria and his team shows the importance of not relying solely on clinical trials, and more observational studies should be conducted to find concrete evidence that exercise benefits the brain.
“You don’t really get a chance to know whether the exercise is working, because it’s such a short duration and if your sample sizes are too small, there’s no way you have enough power to even detect if there’s a positive effect,” Rao said.
Research on animals with shorter lifespans, like mice, indicates that exercise can lead to greater neural connections and enhanced blood flow, suggesting potential long-term advantages for humans, Rao added.
Ciria is not suggesting that physical activity has no effect on the brain or an individual’s health, but rather more in-depth trials should be conducted before organizations recommend exercise to improve brain function.
“Engaging in physical exercise brings not only physical but also social benefits, as we connect with others by forging social bonds, participating in collective activities that give us a sense of belonging, and building new sources of social support. Above all, we strongly believe in the pleasure of doing something for its own sake. The value of exercising may lie simply in its enjoyable nature,” Ciria concluded.
