Some 19,458 participants underwent an assessment of their fitness level, with their maximal time on a treadmill used as it is highly correlated with oxygen consumption (VO2) maximum in men and women. Treadmill times were split into age- and sex-specific quintiles, with quintile one considered ‘low fit’.
Higher fitness levels, as defined by increasing quintiles, was associated with a reduced risk of dementia. Participants in quintile five, the highest level of fitness, had a significant 36% reduced risk of dementia, compared with those in quintile one. Participants in quintile four had a 30% reduced risk, compared with patients in quintile one, and quintile three was associated with a 21% reduced risk, compared with quintile one.
What does it mean for GPs?
The US researchers concluded that ‘physical activity changes in midlife may lead to improved fitness levels, resulting in less all-cause dementia with aging.’ They noted that previous research had shown ‘moderate intensity for at least 150 minutes per week for five to six months’ improves VO2 max sufficiently to increase fitness levels in adults.