Although by no means invincible, the human body is nevertheless engineered for strength, power, and endurance. This program helps viewers understand the awe-inspiring capabilities of the human skeleton and muscular system, as well as the important role of adrenaline in making these systems function. Case studies spotlight an injured hiker who lifted a 1,200-pound boulder off his chest; a police officer who was able to outrun a raging firestorm; a man who survived a tornado’s wild ride only because he was first knocked unconscious; and more. Sophisticated 3-D animation depicts a wide range of physiological wonders, from the impact-absorbent capacity of knee cartilage to the neurological detours that allow athletes to play through pain. A Discovery Channel Production. Part 4 of the series Human Body: Pushing the Limits. (43 minutes)