The American College of Sports Medicine recommends that to maintain health, adults should engage in 150 min of moderate/vigorous physical activity (MVPA) per week. The purpose of the current study was to investigate the lowest MVPA dose possible to maintain functional fitness. Functional fitness was assessed using the Senior Fitness Test in 101 women (75.0 ± 7.2 years) from two Midwestern communities. Accelerometer determined daily activity level was assessed for 7 days as participants went about their normal daily activities. MVPA was determined via proprietary filtering, and time spent in this intensity was calculated. A 5-day average of time spent in MVPA was organized into four groups. ANOVAs revealed significant differences between activity groups on all functional fitness measures except back scratch and sit and reach. Results indicate that to maintain lower body function in older women, a threshold of 20 min/day of MVPA for 5 days is needed.