As adults reach advanced ages, the purpose of physical activity shifts from disease prevention to functional fitness (FF) and mobility. Higher levels of FF contribute to the ability to live independently. PURPOSE: To determine the amount of activity necessary to positively impact functional fitness, by determining cutoff points in which additional minutes in moderate/vigorous physical activity (MVPA) do not further improve functional fitness. METHODS: FF was assessed by the Senior Fitness Test (Chair Stand, Arm Curl, 6 min Walk, Up-and-Go, Sit and Reach, and Back Scratch) in 125 women (73.42 ± 8.84 yrs) from 2 Midwestern communities. Participants wore an accelerometer for 7 days without altering their normal activity. Accelerometer data were downloaded, MVPA determined via proprietary filtering, and time spent in each intensity (sedentary, low, moderate, vigorous) was calculated. A 5 day average of time spent in MVPA was organized into 4 groups (see Table). RESULTS: ANOVAs revealed significant differences between groups on all measures except sit and reach. Results indicate a threshold of 20 min, suggesting that engaging in more MVPA yields no additional statistical gain on the lower body strength and mobility measures of chair stand, up-and-go, and 6 min walk. With regard to upper body strength and flexibility, less than 10 min of MVPA is detrimental to performance. CONCLUSIONS: A threshold of 20 min of MVPA per day is recommended to assist in the maintenance of lower body function in older women. While ACSM recommends that to maintain health all adults accumulate at least 30 minutes of MVPA 5 days/wk, our data suggest that at least 20 min may be sufficient to maintain lower body function in older women.