Better cardio fitness is linked to faster cognitive processing speed in young adults

A small study of university students in Spain found that better cardiorespiratory fitness is associated with better cognitive processing speed and a smaller volume of the cingulate cortex of the brain. However, brain volume differences did not explain the links between cardiorespiratory fitness and cognition. The paper was published in Physiology & 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. A person with good cardiovascular fitness can walk fast, run, cycle, swim, or do other continuous activities for longer periods without becoming exhausted quickly. It is often called aerobic fitness because it depends heavily on oxygen-based energy production, and it is an important component of overall physical fitness.

A common scientific measure of cardiorespiratory fitness is VO₂ max, which estimates the maximum amount of oxygen the body can use during intense exercise. Cardiorespiratory fitness can be improved through regular aerobic activities such as brisk walking, jogging, cycling, swimming, dancing, or rowing.

Better cardiorespiratory fitness is associated with a lower risk of cardiovascular disease, type 2 diabetes, high blood pressure, and early death. It can also improve everyday functioning, mood, sleep, and general energy levels. Low cardiorespiratory fitness means the body has more difficulty sustaining activity that requires a continuous oxygen supply.

Neuroimaging studies indicate that certain physical fitness components, primarily cardiorespiratory fitness and muscular strength, are associated with larger volumes in specific brain structures. However, much of this evidence comes from older or younger age groups.

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“What led us to study the impact of physical fitness in young adults was the fact that current literature on the effects of physical fitness on brain health has mainly focused on older adults or children, with less research available on young adults, even though this is a critical developmental stage in which long-term health behaviors are established that may influence brain health in later stages of life,” said study author and postdoctoral researcher Neus Camins-Vila of the National Institute of Physical Education of Catalonia at the University of Lleida in Spain.

To fill this gap, the researchers conducted a study examining the associations between cardiorespiratory fitness, strength, flexibility, and balance in relation to the volumes of specific brain regions and the participants’ overall neuropsychological profiles. They also sought to determine if sex differences moderated any of these relationships.

Study participants were 94 undergraduate and graduate university students from Barcelona, Spain, and its surroundings, recruited through social media and posters. To be included, participants were required to be between 18 and 25 years of age, to be sufficiently proficient in either Spanish or Catalan to follow instructions, and to have self-reported a regular level of physical activity over the past six months. There was also a list of medical conditions that would exclude prospective participants from the study.

After joining the study, participants first completed an online questionnaire covering demographics and medical history. This was typically followed by three face-to-face sessions involving an evaluation of physical fitness, magnetic resonance imaging (MRI) of the brain, and a cognitive assessment. (Due to the COVID-19 pandemic, the last 14 participants in the study had to complete their cognitive assessments remotely via Zoom, though their physical fitness tests were still conducted in person with safety measures.)

The cognitive assessment lasted 60 to 90 minutes. During this time, participants took a series of neuropsychological tests covering attention and cognitive processing speed (i.e., attention-speed), executive functioning, memory, and visuospatial function. The physical fitness assessment focused on cardiorespiratory fitness, strength, flexibility, and balance.

Results showed that students with higher cardiorespiratory fitness tended to have better processing speed and a smaller volume in the cingulate cortex region of the brain. The researchers theorize that a smaller cingulate cortex in this age group may actually be a sign of advanced, healthy brain maturation rather than a negative outcome, as the brain naturally refines and myelinates connections to become more efficient during early adulthood.

When analyzing the data by sex, different patterns emerged. In men, flexibility (the ability of joints and muscles to move through their 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. The researchers suggest that very high flexibility in women may be linked to joint hypermobility, a condition that can cause pain or fatigue, which could negatively impact cognitive test speeds.

In women, better visual memory was associated with higher strength, while better verbal memory and processing speed were associated with better cardiorespiratory fitness. Balance showed a complex relationship in women: better balance was linked to better attention and processing speed, but worse visual and overall memory. Furthermore, a smaller volume of the hippocampus region of the brain in women was associated with higher flexibility, while a larger hippocampus was associated with better balance.

Ultimately, the findings highlight that brain health and exercise are deeply intertwined, regardless of age.

“This study shows that, even in young adults, physical fitness is associated with cognitive performance and brain structure,” Camins-Vila said. “Additionally, some of these relationships differ between males and females.”

The study contributes to the scientific understanding of the links between cognitive abilities and physical fitness. However, it should be noted that the study authors carried out a large number of statistical tests, but only a few of them returned statistically significant results.

Despite these limitations, the research lays important groundwork for future explorations into how specialized exercise might improve cognitive functioning.

“Our next steps are to continue investigating the impact of different strategies on brain health across different populations,” Camins-Vila said.

The paper, “Associations between fitness components and brain health in young adults: A cognitive and brain volume MRI study exploring sex 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 Mataró.