
A new study highlights an encouraging finding: individuals with a high level of physical fitness have a significantly lower risk of developing dementia, particularly those with a genetic predisposition for the disease. This groundbreaking research suggests that enhancing cardiorespiratory fitness (CRF)—a measure of the body’s ability to deliver oxygen to muscles—could help reduce the likelihood of dementia by as much as 35%. These results were published in the British Journal of Sports Medicine.
What is Cardiorespiratory Fitness (CRF) and How Does It Relate to Cognitive Health?
Cardiorespiratory fitness is crucial for overall health, and it is particularly vital for brain function. This measure of physical fitness reflects how well the circulatory and respiratory systems work together to supply oxygen to the muscles during exercise. Research has consistently shown that a higher level of CRF is associated with better cognitive performance and a reduced risk of dementia in the long term.
As we age, however, CRF tends to decline due to the loss of muscle mass and other factors. Previous studies have already demonstrated that lower CRF is a strong predictor of cardiovascular diseases such as heart attacks and strokes, as well as an increased risk of premature death.

The Study: A Deep Dive into the Connection Between Fitness and Dementia
For the first time, a large-scale study involving over 61,000 participants, aged 39 to 70, has provided conclusive evidence linking CRF to a lower risk of dementia. The participants were all initially free of dementia and were monitored for up to 12 years as part of the UK Biobank study, which began between 2009 and 2010.
At the start of the study, participants underwent a six-minute exercise test on a stationary bike to estimate their CRF levels, while cognitive function was evaluated through neuropsychological tests. To measure genetic predisposition to dementia, researchers used a polygenic risk score for Alzheimer’s disease.
Significant Findings: Higher Fitness Equals Lower Dementia Risk
The results were striking. By the end of the study period, 553 participants had developed dementia (roughly 0.9% of the group). The researchers divided participants into three equal groups based on their CRF levels and found a clear connection between higher fitness and a lower incidence of dementia. Individuals with the highest levels of CRF had not only better cognitive performance but also a delayed onset of dementia by nearly 1.5 years compared to those with lower CRF levels.
“Compared with people with low CRF, the incidence rate ratio of all dementia was 0.6 for people with high CRF—and onset of dementia was delayed by 1.48 years,” said study author Professor Weili Xu from the Karolinska Institute. Moreover, the risk of dementia was reduced by 35% in those with moderate to high genetic predisposition for the disease.
Understanding the Mechanisms: CRF and Genetic Risk
While the study establishes a strong correlation between CRF and reduced dementia risk, it is important to note that this is an observational study, meaning it cannot conclusively prove cause and effect. As Professor Xu explained, further research is necessary to explore the mechanisms behind the link, especially concerning how CRF interacts with genetic risk factors to affect dementia outcomes.
“Our study shows that higher CRF is associated with better cognitive function and decreased dementia risk,” said Professor Xu, reinforcing the idea that maintaining or improving physical fitness is an essential step in mitigating cognitive decline.

The Implications for Public Health
The findings of this study offer a compelling case for promoting physical fitness as part of a preventative strategy for dementia, especially for individuals genetically predisposed to the condition. By focusing on improving CRF, public health initiatives may be able to delay the onset of dementia, potentially improving quality of life for millions of people worldwide.
However, as the research is still ongoing, it remains to be seen how specific interventions might be implemented in practice. What is clear, though, is that CRF is an important factor in brain health, and further studies will help clarify how best to use this information to reduce dementia risk.
In conclusion, the evidence points to the idea that higher cardiorespiratory fitness could serve as a protective factor against dementia, especially for those genetically at risk. The promise of further research in this field offers hope for future strategies aimed at reducing the impact of dementia and improving the quality of life for at-risk populations.