Greater cross education following training with muscle lengthening than shortening

The hypothesis was tested that the magnitude of cross education is greater following training with muscle lengthening than shortening. Changes in contralateral concentric, eccentric, and isometric strength and vastus lateralis and biceps femoris surface electromyographic (EMG) activity were analyzed in groups of young men who exercised the ipsilateral quadriceps with either eccentric (N = 7) or concentric (N = 8) contractions for 36 sessions over 12 wk. Control subjects (N = 6) did not train. Concentric training increased concentric strength 30% and isometric strength 22%, and eccentric training increased eccentric strength 77% and isometric strength 39% (all P 0.05). It was concluded that the greater cross education following training with muscle lengthening is most likely being mediated by both afferent and efferent mechanisms that allow previously sedentary subjects to achieve a greater activation of the untrained limb musculature.