Modulating effects of fitness and physical activity on Alzheimer's disease: Implications from a six-month randomized controlled sports intervention

Background Physical activity and fitness are major targets in Alzheimer's disease (AD) preventive research. However, current research is heterogeneous and often disregards the relationship between these parameters and disease outcomes. Objective To assess the effects of physical activity and fitness on AD within the context of a multicomponent sports intervention. Methods 46 participants with early-stage AD (mean age 70 ± 7 years, 18 women, mean Montreal Cognitive Assessment (MoCA) score 19±5) were included in a six-month randomized controlled trial (Dementia-MOVE), participating in either a multicomponent sports intervention or a control condition with a psychoeducational program. The modulating effect of fitness and physical activity changes on AD outcome parameters such as cognition, function and cerebral brain structure from 3T-MRI were examined using multiple linear regression analyses. Results An increase in VO 2 max was associated with assignment to the intervention group ( p = 0.016), lower baseline fitness ( p = 0.001), and an increased rate of physical activity ( p = 0.046). Only in the intervention group, ΔVO 2 max had a beneficial modulating effect on the MoCA score ( p = 0.039), the executive functions ( p = 0.017) and regional brain volumes of the temporal lobe, e.g., the hippocampus ( p = 0.044). High daily step count was associated with preserved executive functions ( p = 0.001), and caregivers’ quality of life ( p ≤ 0.001) in the overall sample. Conclusions Our results confirm that multicomponent exercise improves cardiorespiratory fitness in AD, which is associated with advantageous developments in cognitive performance and preservation of brain structure. These findings suggest that especially patients with comparably worse cognition and fitness benefit and should be encouraged for activity engagement.