This is a cross-sectional, observational study which will enroll up to 28 healthy, older adults (65-85 y, BMI 20-35 kg/m2), and stratify by current self-reported physical activity level (equal inactive vs. equal highly active).~Aim 1: Investigate whether physical activity level is associated with GPLD1.~Aim 2: Investigate whether cognitive function and brain structure/function are associated with GPLD1.
The investigators are conducting a cross-sectional, observational study to investigate whether plasma GPLD1 concentrations are associated with higher cognitive function and better brain structure and function in two groups of older adults with high or low levels of physical activity.