The aim of this study is to understand the affects of grip strength and manual dexterity in activities of daily living (ADL) in persons with Down syndrome (DS). This is important because it could help with future interventions that are focused around improving related disadvantages in this particular population. Ten participants with DS performed the manual dexterity tests (i.e., Purdue Pegboard) and measured their grip strength with a hydraulic dynamometer. Overall, grip strength was lower than the average for the typical population and was reduced after aeorbic exercise. Improvements, however, were found in their manual dexterity from pre-test to post-test. This indicates that the assisted moderate intensity exercise intervention helped their dexterity performance. The improvements in dexterity are consistent with previous research conducted by Ringenbach et al. (2007). These results suggest that a moderate intensity treadmill walking exercise intervention can increase precision and efficiency in dexterity in persons with Down syndrome, however their grip force production may be stimulated by another means.