Repeat trials of a race walker were analyzed to ascertain the contribution to energy changes made by the lower limb muscles. A sagittal plane link segment model was used to calculate mechanical powers at the hip, knee and ankle. The ankle plantarflexors provided the major energy necessary to propel the body forward. Muscles about the hip contribute to a lesser extent via energy generation and transfer. At the knee, the muscles acted mainly as energy absorbers and did not contribute to forward propulsion. Mechanical powers calculated for the race walker were compared to other forms of locomotion. Patterns unique to the race walker were identified and discussed.