Higher cardiorespiratory fitness in old age is associated with the preservation of several core aspects of cognitive skills that are vulnerable to age-related decline, according to research published online in the British Journal of Sports Medicine.
And this association holds regardless of the main risk factors for cognitive decline: age and carriage of the high-risk APOE4 gene, the findings show.
Cardiorespiratory fitness is a physiological measure of aerobic capacity that can be modified by regular aerobic exercise. Although it has been associated with a reduced risk of age-related cognitive decline and dementia, it is not clear what aspects of cognition it might affect.
The researchers therefore wanted to find out whether cardiorespiratory fitness was associated with core cognitive performance domains in 648 cognitively healthy 65-80 year olds (mean age 69).
Cardiorespiratory fitness was defined as the highest oxygen consumption (VO2max) recorded during a treadmill running test, while cognitive ability was assessed based on the results of a comprehensive battery of validated neuropsychological tests administered over two days.
The tests include several tests to measure five domains: processing speed; working memory; visuospatial processing; episodic memory; and executive function/attention control, including planning and organizational skills.
Most participants were women (461;71%) and had an average of 16 years of education. About 15% reported taking a beta blocker, a drug used to treat heart disease.
Participants had an average VO2max of 21.68 ml/kg/min. A good VO2max for men is 30–40 ml/kg/min. The equivalent figure for women is 25–35 ml/kg/min.
Of the 640 genotyped participants, 174 (27%) were APOE4 carriers.
As expected, older age was associated with poorer performance in all five cognitive domains, after taking into account gender, years of education and weight (BMI), while education level was associated with better performance.
But higher levels of cardiorespiratory fitness were associated with better performance in all five cognitive domains assessed, regardless of age and APOE4 gene carrier.
The association between cardiorespiratory fitness and cognitive performance was greater in women, among those with fewer years of education, and among those taking beta blockers, on measures of processing speed and executive function/attention control.
This is an observational study and as such no firm conclusions can be drawn about cause and effect. The researchers also acknowledge that not all cognitive domains were assessed (language, for example) and that the participants were all relatively inactive, limiting the range of fitness levels observed.
But they write: “These findings demonstrate the magnitude of cognitive benefits associated with higher [cardiorespiratory fitness]and highlight several key factors that may influence the relationship between fitness and neurocognitive health in old age.”
In an attempt to explain the associations found, the researchers suggest that aerobic fitness may improve blood flow in the brain, reduce oxidative stress, forge new synaptic connections, stimulate the growth of neurons and improve neurotransmitter systems, as well as the shape and structure of brain cells can change. gray and white matter.
Psychosocial factors related to cardiorespiratory fitness, such as improving mood, reducing fatigue and improving sleep, can also influence cognitive skills, they add.
They conclude: “These findings highlight [cardiorespiratory fitness] as an important health factor for the maintenance of multidomain cognitive functioning in old age. Understanding moderators of this relationship could aid in the development of individualized training prescriptions that target this [cardiorespiratory fitness] to optimize cognitive health as we age.”
Source:
Magazine reference:
Oberlin, L.E., et al. (2024). Cardiorespiratory fitness is associated with cognitive function in late adulthood: basic findings from the IGNITE study. British Journal of Sports Medicine. doi.org/10.1136/bjsports-2024-108257.