Cross education is a neurophysiological phenomenon where an increase in strength is witnessed within an untrained limb following unilateral strength training in the opposite, contralateral limb.[1]
Cross education can also be seen in the transfer of skills from one limb to the other.
A resistance trainer witnesses strength gains in her left and right biceps after participating in a strength training program for only her right biceps. This phenomenon is due to factors at the muscular, spinal and neural levels.
A basketball player learns to dribble a basketball with his right hand and then successfully performs the task with his left hand even though he had undergone no previous training with his left side.