Overview
- In older adults with elevated brain amyloid, 3,000–5,000 steps per day was associated with an average three-year delay in cognitive decline, rising to about seven years at 5,000–7,500 steps.
- Benefits emerged at low step counts and plateaued beyond roughly 7,500 steps, offering a realistic target below the popular 10,000-step goal.
- The longitudinal study tracked 296 cognitively unimpaired adults for about nine years using a 7‑day pedometer baseline, annual cognitive testing, and PET imaging.
- Higher activity was not linked to lower amyloid levels but to slower accumulation of tau tangles, which statistically mediated the cognitive effects.
- Authors note the observational design and a mostly highly educated, non-Hispanic white cohort limit generalizability, and they call for trials to define which activity patterns matter most.