Twelve weeks of exercise training improves cognitive status, physical performance and quality of life in Alzheimer's disease: A systematic review and meta-analysis

Alzheimer's disease (AD) is a progressive neurodegenerative disorder in which there is slow and gradual impairment of mental function. Considering the increase in cases due to population aging, the potential benefits of physical training in AD are of great importance and need further elucidation. This study aims to identify the impact of physical training on crucial aspects of AD such as cognitive status, physical performances, quality of life and activities of daily living. The bibliographic research was conducted according to the guidelines outlined in PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). After the selection process, 26 studies were included in the systematic review and meta-analysis. Physical training for up to 12 weeks had a moderate effect on the cognitive status (SMD: 0.34; 95 % CI: 0.07-0.61; p = 0.016), the physical performance (SMD: 0.75; 95 % CI: 0.43-1.06; p = 0.000) and the quality of life (SMD: 0.40; 95 % CI: 0.17-0.63; p = 0.567) of patients with AD, but did not affect their daily living activities (SMD: -0.10; 95 % CI: - 0.31-0.12; p = 0.621). Physical training lasting from 16 to 24 weeks had a moderate effect only on the physical performance (SMD: 0.51; 95 % CI: 0.23-0.79; p = 0.000) of patients. Physical training for up to 12 weeks already leads to gains on the cognition, the physical performance and the quality of life of individuals with AD. Beyond the available evidence on health promotion resulting from physical training, guidelines should be established to define ideal training loads for patients with AD. Specific practical recommendations concerning the types, frequency, intensity or duration of physical exercise that may be the most efficient for ameliorating cognition, physical performance and quality of life of individuals with AD are still unclear.