Bone, blood, and cartilage set a strict ceiling on what a human body can endure, long before a superhero punch would even reach its climax on screen. Real tissue fails at specific thresholds of stress and strain, and those limits are far lower than blockbuster fight scenes suggest.
In high-speed impacts and long falls, the key numbers are peak acceleration and impulse. Brain tissue starts to suffer diffuse axonal injury when the head experiences rapid rotational acceleration; the skull does not need to crack for consciousness and memory to vanish. Internal organs, loosely suspended in the torso, continue moving when the chest stops, causing shear forces that tear blood vessels and rupture the liver. The same momentum that throws a hero through several walls would, in a human, translate into catastrophic deceleration trauma after only a single hard stop.
Energy blasts raise a different set of constraints. Intense electromagnetic radiation deposits energy as heat at a rate far above what thermoregulation and basal metabolic rate can dissipate, denaturing proteins and disrupting cell membranes. Shock waves from explosions create rapid spikes in ambient pressure, leading to barotrauma in the lungs and eyes even without visible burns. The connective tissues that anchor joints and the collagen scaffolds in skin and fascia also have finite tensile strength; once those fibers exceed their elastic limit, they do not bounce back between blows.
All of this runs into the same hard wall: evolutionary design optimized for everyday mechanical loads, not for surviving building-leveling collisions. A living body operates near a narrow band of pressure, temperature, and acceleration, and even brief excursions outside that envelope are enough to turn a cinematic stunt into a fatal endpoint.
