For many years, the scientific consensus was clear: physical exercise is not only excellent for physical health but also beneficial for cognitive functions. In particular, it was believed that exercise improves executive functions—the mental processes that allow us to plan, solve problems, organize tasks, and adapt to new situations. A vast body of research seemed to support this, showing that physical activity could enhance mental clarity both in the short term (such as that post-jogging mental clarity) and in the long term, with cumulative effects. Children and the elderly were seen as the primary beneficiaries, but the evidence suggested that anyone could become cognitively sharper—or at least more efficient—by engaging in regular exercise.
A meta-analysis published in 2020, led by Swiss researcher Sebastian Ludyga, was among the studies that helped cement this belief. It concluded that exercise improves cognitive abilities, and the World Health Organization even referenced these findings in a guide published that same year. It was widely accepted that exercise not only promoted better health but also led to improved academic performance, decision-making, and work productivity.
However, in 2023, this apparent consensus was shattered by a landmark review conducted by Spanish researcher Luis Ciria and his colleagues. Their review, published in Nature, included 24 previous meta-analyses on the topic, and their conclusions were striking: the evidence did not support the idea that exercise had a clear and robust effect on cognitive function. “We saw that the results were not solid, that the supposed beneficial effect was tenuous,” Ciria remarked in a video interview. This finding triggered a response from 21 researchers from around the world—including Ludyga and French researcher Boris Cheval—who had previously supported the connection between exercise and cognitive function. The ensuing debate, published in Nature in 2024, highlighted deep methodological differences between the two sides, marking a high-profile scientific controversy.
The Crux of the Debate
At the heart of the controversy lies a methodological dispute over the types of studies that should be considered valid for making firm conclusions. Ciria and his team argue that only randomized controlled trials (RCTs)—which are considered the gold standard in scientific research—should be used to assess the impact of exercise on cognition. RCTs are designed to minimize bias, making them the most reliable way to establish causal relationships. Furthermore, the 2023 review excluded any activities that required significant cognitive effort, such as team sports or martial arts. The premise was clear: in order to isolate the effects of physical exercise on cognition, one should focus on exercise that is as mentally “pure” as possible, without any cognitive engagement that could influence the results.
“It’s very difficult to separate the purely physical aspect,” Ciria admits. However, he stresses that if we are to conduct rigorous science on this topic, we must try to eliminate all potential cognitive contamination.
What Is “Pure” Exercise?
The problem, according to Ludyga and Cheval, is that under Ciria’s strict criteria, virtually no exercise qualifies as “pure enough” to meet the rigorous standards of exclusion. Ludyga points out that “any form of exercise has benefits,” although the most significant impact on cognition is seen with activities that involve coordination. He explains that if the goal is to clear the mind immediately, the best option is exercise that does not require significant cognitive effort. “Think about when students are struggling to focus, and they’re given aerobic exercises. If these don’t require cognitive functions, that’s perfect, because those are the very functions you are trying to restore.”
Cheval further emphasizes that the physical activities that most improve executive functions are those that require decision-making, such as team sports, and not just repetitive, mechanical exercise. He and Ludyga both agree that it is impossible to separate the body and mind entirely when engaging in physical activities. Whether you’re shooting a basketball, executing a precise karate kick, or lifting weights, the brain is involved in some capacity, as it is needed to control motor functions. Yet both researchers argue that much remains unknown, as the relationship between the body and mind is deeply complex, involving multiple factors.
Is It Legitimate to Include Cognitive-Engaging Activities?
The scientific community is divided on whether activities that are cognitively engaging should be excluded from studies on the body-mind relationship. Ciria and his colleagues argue that only those exercises which do not require cognitive effort should be included, while Ludyga and Cheval believe that cognitive engagement is an inherent part of most physical activities and cannot be disregarded. As the debate continues, another argument in favor of the benefits of exercise on cognition has emerged: neurobiological mechanisms that may explain the cognitive improvements linked to regular physical activity.
The Role of Brain-Derived Neurotrophic Factor (BDNF)
One promising avenue of research centers on brain-derived neurotrophic factor (BDNF), a protein whose levels increase with exercise and has neuroprotective properties. Studies suggest that BDNF plays a crucial role in memory and learning processes. According to Cheval, there are also indications of structural changes in the brain, such as increased connectivity in certain areas, and functional changes, like increased neurovascular activity, as a result of sustained physical exercise. These findings support the notion that regular physical activity might indeed enhance cognitive function, but the mechanism behind it is still being investigated.
Ciria, however, remains skeptical. He argues that while exercise might have cognitive benefits, it is not the physical activity itself that causes these effects. Instead, the benefits are likely a result of the social, relational aspects of exercise, such as the social interaction involved in group activities, the contact with nature, or even improvements in sleep and diet that often accompany regular exercise. These factors, he suggests, might be more responsible for any cognitive improvements observed.
The Role of Exercise in Improving IQ and Cognitive Flexibility in Children
As the debate over the body-mind connection continues, new studies keep emerging. A recent meta-analysis by Javier S. Morales, a researcher at the University of Cádiz, published in Pediatrics, explored the effects of physical training on children and adolescents. Morales concluded that physical exercise programs improved the IQ of children aged six to fourteen by an average of four points, equivalent to the cognitive gains of an entire school year. He also conducted a review of early childhood studies, published in Sports Medicine, which found substantial improvements in working memory and cognitive flexibility.
Morales and Cheval advocate for integrating more physical exercise into school curricula, not just to promote healthy habits but to enhance learning capabilities. They argue that exercise is a low-cost intervention that can lead to more efficient and agile learning. According to Morales, these cognitive benefits of exercise are particularly evident in young children, whose brains are still developing and highly responsive to external stimuli like physical activity.
The Future of Exercise and Cognitive Function
While the controversy continues, it is clear that the relationship between physical exercise and cognition is more complex than once thought. The scientific community remains divided, with some researchers emphasizing the importance of rigorous methodologies and narrow study parameters, while others argue that exercise in its various forms can have significant cognitive benefits, even if those benefits are difficult to isolate or measure.
What is certain, however, is that exercise remains a cornerstone of physical and mental health. Whether or not exercise makes us “smarter” in a direct, measurable sense, its role in improving executive functions like memory, focus, and decision-making seems undeniable. For children and adolescents, the potential benefits of regular physical activity on cognitive development could be a compelling reason to incorporate more exercise into educational settings. As research continues, it is likely that new findings will further clarify the mechanisms behind the relationship between the body and the brain.
In the meantime, it may be best to continue encouraging regular physical activity for its well-established benefits on both physical health and mental well-being, while scientists work to unravel the full extent of its cognitive impacts.
