Desktop interaction solutions are often inappropriate for mobile devices due to small screen size and portability needs. Speech recognition can improve interactions by providing a relatively hands-free solution that can be used in various situations. While mobile systems are designed to be transportable, few have examined the effects of motion on mobile interactions. We investigated the effect of motion on automatic speech recognition (ASR) input for mobile devices. We examined speech recognition error rates (RER) with subjects walking or seated, while performing text input tasks and the effect of ASR enrollment conditions on RER. RER were significantly lower for seated conditions. There was a significant interaction between enrollment and task conditions. When users enrolled while seated, but completed walking tasks, RER increased. In contrast, when users enrolled while walking, but completed seated tasks, RER decreased. These results suggest changes in user training of ASR systems for mobile and seated usage.