Super-strength

Hysterical strength, or superhuman strength, is a display of extreme strength by humans, beyond what is believed to be normal, usually occurring when people are in life and death situations. Common anecdotal examples include parents lifting vehicles to rescue their children. Such examples, however, have not been proven and have been dismissed by doctors across the world. The extra strength is believed to come from adrenaline, though incidents are rare and never proven as there were no examinable evidence or witnesses; research into the phenomenon is difficult, though it is thought that it is theoretically possible.

Superhuman strength may occur during excited delirium.

The most common anecdotal examples are of parents lifting vehicles to rescue their children, and when people are in life and death situations. Hysterical strength can result in torn muscles due to higher mechanical stress.

Early experiments showed that adrenaline increases twitch, but not tetanic force and rate of force development in muscles. It is questionable, however, as to whether adrenaline, released from the adrenal medulla into the venous circulation, can reach the muscle quickly enough in order to be able to cause such an effect in the midst of a crisis. It may be that noradrenaline released from sympathetic nerve terminals directly innervating skeletal muscle, has more of an effect over the timescale of seconds.

Amphetamine and other stimulants are used by some athletes for their psychological and performance-enhancing effects. In competitive sports, this form of use is prohibited by anti-doping regulations. In healthy people at oral therapeutic doses, amphetamine has been shown to increase physical strength, acceleration, stamina, and endurance, while reducing reaction time. Like methylphenidate and bupropion, amphetamine increases stamina and endurance in humans primarily through reuptake inhibition and release of dopamine in the central nervous system.

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