Objective Physical Activity Accumulation and Brain Volume in Older Adults: An MRI and Whole-Brain Volume Study

Abstract A decrease in brain volume (ie, brain atrophy) is a marker of cognitive health in older adults. Insufficient weekly accumulation of moderate and vigorous physical activity (MVPA) has been associated with lower brain volume. As this association has been established for a small number of brain areas and structures and atrophy rates seem to be nonuniform between them, more comprehensive analyses are warranted. We compared the volume of 71 brain areas and structures in 45 older adults who met and did not meet objectively measured MVPA recommendations. In addition, we used multiple regression models to determine whether cardiorespiratory fitness (VO2PEAK), MVPA, and health-related risk factors could affect the atrophy of brain areas and structures. An accelerometer (GT9-X ActiGraph) was worn for 7 days. Participants were then classified into 2 groups: