Here Bonnie and Suzy show you how to do a variation of the resistance exercise they demonstrated in their first mother-daughter act (SI, Feb. 24). The principle here is the same as for any resistance exercise done by two people: the object is not to overcome your partner by superior strength but to "resist" each other to the point where one force balances the other. As the child grows stronger and heavier, the point of balance will, of course, change. Be sure to explain that this is a cooperative venture and not a competition where the parent has the obvious advantage.
Stand facing each other grasping a short, strong stick, the parent's hands together, the child's on either side of the parent's. Put your knees and foreheads together.
Slowly lean back, knees still touching, until arms are straight. Hold for a slow count of five and gradually pull back. Increase the hold count by five each week.