Backward walking, a form of knee rehabilitation shown to protect knee structures, has been predicted to maintain cardiorespiratory fitness. The purpose of this study was to investigate the motor learning effects on oxygen uptake (VO2), heart rate (HR), and ratings of perceived exertion (RPE) during a backward-walking habituation program. Eight males completed baseline measures of VO2, HR, and RPE while walking backwards at 3·2–3·7mph on a treadmill. Backward walking practice was conducted three times/week for 15min. Participants returned to the lab at the end of weeks one–four and walked backwards at the same speed as the baseline session. Statistical analyses revealed significant decreases from baseline to week four in VO2(2·05±0·56 to 1·66±0·28L.min−1, P<0·0001), HR (142·6±24·0 to 118·8±16·8 beatsmin−1, P<0·0001), and RPE (12·7±1·6 to 10·5±1·1,P<0·0001). Backward walking practice resulted in greater economy evidenced by significant decreases in VO2, HR, and RPE as participants became more skilled at this movement.