Abstract
BACKGROUND: Little is known about the associations of midlife- and late life-initiated walking with Alzheimer's disease (AD)-related cognitive decline in humans. We aimed to investigate whether high-intensity, prolonged, midlife-initiated walking is associated with changes in AD-related cognitive decline in physically capable older adults. METHODS: We studied 188 physically capable participants aged 65-90 years without dementia who underwent comprehensive clinical assessment, including of their walking modality (i.e., intensity, duration, midlife- or late life-onset), memory- or non-memory and total cognitive performance, and blood or nutritional biomarkers. RESULTS: The walking group showed better episodic memory (B = 2.852, SE = 1.214, β = 0.144, p = 0.020), but not non-memory cognition, than the non-walking group. High-intensity walking starting in midlife was significantly associated with better episodic memory (B = 9.360, SE = 3.314, β = 0.446, p = 0.005) compared to the non-walking group. In contrast, there were no differences in cognition according to walking duration, regardless of the onset time. The walking group also showed a similar association with overall cognition. CONCLUSIONS: Among physically capable older adults without dementia, walking, particularly at high intensity and starting in midlife, is associated with improved episodic memory, an AD-related cognitive domain. Further attention should be paid to the role of walking in terms of AD prevention.