O papel da atividade física, exercício e aptidão cardiorrespiratória na função cognitiva e prevenção de demência em adultos com comprometimento cognitivo leve

Abstract

This doctoral thesis aimed to (1) identify the role of physical activity in reducing the risk of dementia in healthy people and (2) with mild cognitive impairment (MCI), in addition to verifying the association of aerobic fitness with cognitive function in elderly with MCI. Finally, we aimed to verify the effects of 12 months of high-intensity interval training (HIIT) and high-intensity progressive resistance training (PRT) on the aerobic fitness of older adults with MCI. For the first and second objective, data from the English Longitudinal Study of Aging (ELSA), a cohort study conducted in England, was used. With data from 12,099 adults aged 50 and over, we showed a dose-response relationship between physical activity and the risk of dementia, with moderate-intensity physical activity at least once a week reducing the risk for dementia by 60%. In the second article of this thesis, we observed the same dose-response relationship in people with MCI. Additionally, we showed for the first time that physical activity is able to eliminate the risk of dementia associated with aging. In the third article, we showed that submaximal measures of aerobic fitness including the oxygen uptake efficiency slope (OUES) and the ventilatory threshold are associated with different domains of cognitive function in older adults with MCI. We also revealed that cardiopulmonary exercise testing lasting four minutes is sufficient to produce relevant information about the cognitive status in this population. Finally, we indicated that 12 minutes of HIIT per week for 12 months improved aerobic fitness of older adults with MCI higher than PRT and control exercise group. In the light of these findings, we expected that physical activity and exercise as well as the assessment of aerobic fitness will be recognized as low cost and low risk mechanisms and strategies to prevent and identify impairments in cognitive function in the elderly.