A small study of Spanish university students found that improved cardiorespiratory fitness was associated with increased cognitive processing speed and reduced volume in the brain’s cingulate cortex. However, differences in brain volume alone could not explain the relationship between cardiopulmonary function and cognition. The paper is physiology and behavior.
Cardiovascular fitness is the ability of a person’s heart, lungs, and blood vessels to supply oxygen-rich blood to muscles during sustained physical activity. People with good cardiovascular health can walk fast, run, ride a bike, swim, or do other continuous activities for long periods of time without tiring quickly. It is sometimes referred to as aerobic fitness because it relies heavily on oxygen-based energy production and is a key component of overall physical fitness.
A common scientific measure of cardiovascular fitness is VO₂ max, which estimates the maximum amount of oxygen your body can use during intense exercise. Cardiorespiratory fitness can be improved by regular aerobic exercise such as brisk walking, jogging, cycling, swimming, dancing, and rowing.
Improved cardiovascular fitness is associated with lower risk of cardiovascular disease, type 2 diabetes, hypertension, and early death. It can also improve daily functioning, mood, sleep, and overall energy levels. Poor cardiorespiratory fitness means the body has a harder time sustaining activities that require a continuous supply of oxygen.
Study authors Neus Camins-Vila and colleagues point out that neuroimaging studies have shown that certain components of physical fitness, primarily cardiorespiratory fitness and muscle strength, are associated with greater volume in certain brain structures.
For example, among young adults, previous research has shown that higher cardiorespiratory fitness is associated with larger volumes in some areas of the brain. Researchers conducted a study examining the association between the volumes of specific brain regions and cardiorespiratory fitness, muscle strength, flexibility, and balance in relation to participants’ overall neuropsychological profiles. They also sought to determine whether gender differences moderated any of these relationships.
Study participants were 94 undergraduate and graduate students living in Barcelona, Spain and the surrounding area, recruited through social media and posters. Participants were required to be between the ages of 18 and 25, to be fluent enough in Spanish or Catalan to follow instructions, and to self-report a regular level of physical activity over the past six months. There was also a list of medical conditions that would exclude future participants from the study.
After participating in the study, participants first completed an online questionnaire covering demographics and medical history. This was followed by three face-to-face sessions, including a cognitive assessment, physical fitness assessment, and brain magnetic resonance imaging (MRI).
Cognitive assessments lasted 60–90 minutes. During this period, participants underwent a series of neuropsychological tests targeting attention and cognitive processing speed (i.e., attention speed), executive function, memory, and visuospatial function. The physical fitness assessment focused on cardiorespiratory fitness, muscle strength, flexibility, and balance.
The results showed that students with high cardiorespiratory fitness tended to have faster processing speeds and smaller volumes in the cingulate cortex region of their brains. The researchers theorize that the smaller cingulate cortex in this age group may actually be a sign of advanced and healthy brain maturation, rather than a negative outcome, as the brain naturally prunes connections to become more efficient in early adulthood.
Analyzing the data by gender revealed different patterns. In men, flexibility (the ability of joints and muscles to move through a full range of motion without pain or excessive stiffness) was associated with higher processing speed. In contrast, higher flexibility was associated with lower processing speed in women. Researchers suggest that women’s greater flexibility may be associated with joint hypermobility, which can cause pain and fatigue, and may negatively impact speed on cognitive tests.
In women, better visual memory was associated with better muscle strength, and better verbal memory was associated with better cardiorespiratory fitness. Furthermore, the smaller volume of the hippocampal region of the female brain results in greater flexibility but poorer balance.
“In young adults, various physical fitness components are associated with cognitive function and brain volume, and some associations, particularly those related to physical flexibility and attention/processing speed, vary by sex at birth. Brain volume does not explain the observed fitness-cognition associations,” the study authors concluded.
This study contributes to the scientific understanding of the relationship between cognitive ability and physical fitness. However, it should be noted that although the study authors performed a large number of statistical tests, only a few of them yielded statistically significant results. They did this without applying any correction for multiple comparisons. This is a procedure routinely used in research studies to reduce the risk that statistical tests may return statistically significant results simply by chance. This means that many of the reported findings may simply be the product of random variation within the data rather than actual systematic associations between observed traits.
The paper, “Association between fitness components and brain health in young people: A cognitive and brain volumetric MRI study exploring gender differences. The YoungFit study” was authored by Neus Camins-Vila, Adrià Bermudo-Gallaguet, Samira Rostami, Rosalia Dacosta-Aguayo, Judit Escarré-Grifell, Blai Ferrer-Uris, Albert Busquets, Louis Bherer, and Maria. Mataro.

