New research suggests maintaining good cardiorespiratory fitness could significantly reduce dementia risk, even for those genetically predisposed to the condition.

A large-scale study published in the British Journal of Sports Medicine tracked more than 61,000 adults aged 39-70 for up to 12 years, measuring their cardiorespiratory fitness (CRF) – the heart and lungs’ ability to supply oxygen to muscles during sustained physical activity.

At the start of the study, participants completed a baseline 6-minute stationary bike test to establish their cardiorespiratory fitness levels. This one-time submaximal exercise test was chosen specifically because it’s safer and more practical for older adults than maximal exercise testing, which requires participants to exercise to exhaustion. While the test wasn’t repeated during the study period, researchers tracked participants’ health outcomes for up to 12 years.

The research revealed that participants with high CRF levels showed a 40% lower risk of developing dementia compared to those with low fitness levels. Even more significantly, people with genetic risk factors for dementia who maintained high fitness levels reduced their risk by 35%.

The relationship between fitness and brain health appears significant across age groups and becomes particularly clear in later years. The researchers found the protective effects of high fitness remained consistent even among participants over 60 years old. This is especially relevant because cardiorespiratory fitness naturally declines with age – dropping 3-6% per decade when people are in their 20s and 30s, and accelerating to more than 20% per decade by the time they reach their 70s.

While maximal exercise testing isn’t practical for most people, researchers suggest regular aerobic activity, resistance training, or even consistent moderate-intensity lifestyle physical activity can help maintain cardiorespiratory fitness. The study’s findings support the growing evidence that physical fitness plays a vital role in cognitive health as people age.

“Enhancing CRF could be a strategy for the prevention of dementia, even among people with a high genetic predisposition for Alzheimer’s disease,” the researchers noted.