The Jacob's Ladder machine is non-motorized, allowing you to control the pace and movement of its treadmill-style belt. When you pull and run fast, the ladder speeds up, and when you slow or stop, its response is the same and instantaneous. The 40-degree-angled, mountain-climbing position it puts you into during use demands full-body engagement at all times. Aside from the Gronk seal of approval, the Jacob's Ladder has a lot going for it as a fitness machine. I was surprised to learn that the "Gronk Edition" of this step machine does not mean Patriots tight end Rob Gronkowski agreed to another paid endorsement deal. It means the entire Gronkowski family has teamed up with Jacob's Ladder for a fitness collaboration. Gronk Fitness is the brand of a family that has been in the commercial and home gym equipment industry for almost 30 years.