A Jumping Jack, or side straddle hop as it is called in the United States military, is a physical exercise performed by jumping to a position with the legs spread wide and the hands touching overhead and then returning to a position with the feet together and the arms at the sides. More intensive versions include bending down and touching the floor in between each jump. It is also commonly known as a star jump, especially to children of Commonwealth nations. In Canada, the term is stride jump, and the hands are not expected to touch above the head. A similar exercise, as coined by actor Jason David Frank, is called half-jacks. They are just like regular jumping jacks, but the arms go halfway above the head instead of all the way above the head. The arms also hit the sides to help tighten up the sides. While fitness expert Jack LaLanne does not take credit for