Do not punish poor grades by restricting play or sports
A five-month study from the University of Granada quietly overturns a common parental instinct: when children struggle academically, the answer may not be more desk time, but more movement. Tracking children with overweight and obesity through regular aerobic and strength training, researchers found measurable gains in intelligence, cognitive flexibility, and academic performance — with mathematics showing the strongest response. The findings arrive at a moment when Spain faces some of Europe's highest childhood obesity rates, lending the research both scientific and social weight. Exercise, it turns out, is not a distraction from the life of the mind — it may be one of its foundations.
- One in three children in Spain carries excess weight, and new research confirms this is not only a physical crisis but a cognitive one — obesity measurably impairs brain development.
- The instinct to punish poor grades by canceling sports or restricting play may be actively backfiring, according to the study's lead researcher, who urges parents to do the opposite.
- Children who exercised three times weekly for five months showed concrete gains in general intelligence, crystallized knowledge, mental flexibility, and problem-solving — not just fitness.
- The exercise program required no special equipment — just group games, outdoor running, and bodyweight work — making it immediately replicable in any school setting.
- Researchers are now calling for Spain to expand daily physical education to one hour, five days a week, a standard already met by several European neighbors, with the potential to lift outcomes across entire student populations.
A research team at the University of Granada has spent five months tracking what happens to children's minds when their bodies are put to work — and the results make a compelling case for rethinking how schools and parents approach both exercise and academic struggle. The ActiveBrains project followed children with overweight or obesity through a structured program of aerobic and strength training, three sessions per week. By the study's end, participants showed significant improvements in general intelligence, crystallized intelligence, cognitive flexibility, and academic performance, with mathematics and problem-solving registering the strongest gains. The findings were published in JAMA Network Open.
Cognitive flexibility — the mental capacity to shift between tasks, adapt to new rules, and hold competing ideas simultaneously — was among the most striking improvements. It is precisely the kind of thinking modern life demands, and the study showed it responds directly to physical training. Lead researcher Francisco Ortega, who also contributed to the WHO's 2020 physical activity guidelines, offered parents a pointed message: removing children from sports as punishment for poor grades is likely to make things worse, not better. The data points clearly in the other direction.
The urgency behind the research is hard to ignore. Spain ranks among Europe's highest for childhood obesity, with roughly one in three children carrying excess weight — a reality that, this study confirms, carries cognitive consequences alongside physical ones. The exercise program itself was deliberately unglamorous: group games, outdoor running, bodyweight exercises, no specialized equipment, sessions held at roughly 70 percent of maximum heart rate. Researcher José Mora noted that schools already possess everything needed to replicate it.
Ortega's broader ambition is policy change. If Spain were to expand physical education to one hour daily — five hours per week, as some European countries already mandate — the benefits documented in this study could reach entire student populations. Better bodies, sharper minds, and stronger academic outcomes: the research, recently presented at the European Congress of Sports Science in Seville, suggests all three may arrive together.
Researchers at the University of Granada have completed a five-month study that offers parents and educators a straightforward finding: children who exercise regularly perform better in school and show measurable gains in intelligence. The ActiveBrains project tracked students with overweight or obesity who participated in aerobic and strength training three times weekly. By the end of the program, these children demonstrated significant improvements across multiple cognitive measures—general intelligence, crystallized intelligence (the kind tied to vocabulary and learned knowledge), cognitive flexibility, and overall academic performance. Mathematics and problem-solving showed the strongest gains.
The study, published this week in JAMA Network Open, involved researchers from Granada's departments of Physical Education and Psychology, along with collaborators from Spain and abroad. What makes the findings particularly relevant is the timing: childhood is a critical window for both brain development and establishing lifelong habits. The researchers found that sustained physical activity during this period doesn't just build stronger bodies—it reshapes how children's minds work and learn.
Cognitive flexibility, one of the measured improvements, refers to the mental agility required to shift between tasks, adapt to new rules, and hold multiple ideas at once. In a world that demands constant adaptation, this capacity matters. The study showed that regular exercise strengthened it measurably. The academic gains were equally concrete: children improved not just in isolated subjects but in their capacity to solve problems across domains.
Francisco Ortega, the lead researcher and a professor at Granada, offered a direct message to parents: do not punish poor academic performance by restricting play or withdrawing children from sports. The logic seems counterintuitive to many—the instinct is to crack down, to remove distractions. But the data suggests the opposite approach. Exercise is not a distraction from learning; it is a tool that enhances it. Ortega participated in drafting the World Health Organization's physical activity guidelines in 2020, and he points to their recommendation: 60 minutes of moderate-intensity aerobic activity daily, with at least three days per week of high-intensity work and muscle-strengthening exercise.
The context for this research is urgent. Spain ranks among Europe's highest in childhood obesity rates, with one in three children carrying excess weight. Obesity carries obvious physical health consequences, but the Granada study adds another dimension: it impairs cognitive and brain development. The exercise program tested here was deliberately practical—group games, outdoor running, bodyweight strength work, no specialized equipment. Sessions ran at about 70 percent of maximum heart rate, three times weekly for 90 minutes each, totaling 4.5 hours per week.
José Mora, another researcher on the project, emphasized that this type of exercise is entirely transferable to school settings. Schools already have the space and the time; what's needed is the commitment. Ortega's closing observation points toward policy: if Spain increased daily physical education from its current level to one hour per day—five hours per week, as some European countries already do—the gains could extend across the entire student population. Better physical health, better mental health, and as this study demonstrates, better intelligence and academic outcomes. The research was recently presented at the European Congress of Sports Science in Seville, the continent's largest gathering of sports science researchers.
Citas Notables
If your children aren't performing well academically, don't punish them by restricting play or removing them from sports—do the opposite.— Francisco Ortega, lead researcher, University of Granada
Exercise is an effective tool to counteract the negative effects of obesity on cognitive and academic function.— José Mora, University of Granada
La Conversación del Hearth Otra perspectiva de la historia
Why does exercise specifically improve intelligence rather than just general health?
The study measured crystallized intelligence—the knowledge and vocabulary you accumulate through learning. When children exercise regularly, blood flow to the brain increases, and that appears to strengthen the neural pathways involved in memory and language acquisition. It's not that exercise makes kids smarter in some abstract sense; it's that their brains are better positioned to absorb and retain what they're learning in school.
The study focused on overweight children. Does this mean exercise only helps kids who are already struggling with weight?
The study population was overweight or obese, yes, but the researchers believe the benefits would apply broadly. What they're really showing is that exercise counteracts the cognitive damage obesity causes. A child without weight issues might see different baseline improvements, but the mechanism—exercise enhancing brain function—should be universal.
Four and a half hours of exercise per week seems like a lot. Is that realistic for most families?
That's the actual program they tested. But the WHO recommendation is 60 minutes daily, which is one hour a day. Most of that could happen at school during PE class. The real barrier isn't time; it's that many schools have cut PE to make room for academics. The irony is that cutting exercise to improve grades may actually harm grades.
What about the cognitive flexibility piece? That seems almost more important than raw intelligence.
It might be. Crystallized intelligence is about what you know. Cognitive flexibility is about how you think—your ability to switch between problems, adapt to new information, see connections. In a changing world, that's arguably more valuable than memorized facts. The study showed exercise strengthens that capacity measurably.
The researcher said not to punish poor grades by removing sports. But what if a child genuinely needs more study time?
The point isn't that study time doesn't matter. It's that the traditional punishment—no sports, no play—may be counterproductive. A child studying for six hours without physical activity may retain less than a child who studies four hours and exercises two. The brain needs both.