The purposes of this study were to examine the effects of different distances and the inclusion and exclusion of acceleration and deceleration distances on the measurement of self-paced and fastest gait speeds in younger and older adults. The self-paced and fastest gait speeds of younger and older adults were measured over 4-m and 10-m walkways with the acceleration and deceleration distances included and excluded in the measuring distance. The results indicated gait speeds (both self-paced and fastest) measured over different distances were comparable only if a distance for acceleration and deceleration was excluded from the measuring distance to obtain stable and comparable gait speeds. Similar results were found for younger and older groups.