There is limited information about adaptive response to external gait perturbations in the running literature. Adaptation and de-adaptation represent two important functional abilities needed for efficient movement, optimal performance, and injury prevention. Quick response to unpredictable task demands is necessary to avoid traumatic injuries, while efficient return to preferred state is necessary to avoid cumulative stress.  Preferred movement patterns are often associated with minimal energy expenditure and reduced joint loading. Longer time needed to return to preferred movement pattern over multiple exposures during a race or run lead to accumulated time out of preferred state. This accumulation may negatively impact metabolic cost and increase cumulative joint loads, which hamper performance and raises the likelihood of injury. The current study aims to understand biomechanical and individual-specific factors that influence functional adaptability and the consequence of poor adaptive response.