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 are of mothers lifting vehicles to rescue their children. The extra strength is believed to come from adrenalin, though incidents are rare, unrepeatable, with no examinable evidence and few witnesses; research into the phenomenon is difficult, though it is thought that it is theoretically possible.
The most common anecdotal examples are of mothers 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.
- In 1982, in Lawrenceville, Georgia, Tony Cavallo was repairing a 1964 Chevrolet Impala automobile from underneath. The vehicle was propped up with jacks, but it fell. Cavallo's mother, Mrs. Angela Cavallo, lifted the car high enough and long enough for two neighbours to replace the jacks and pull Tony from beneath the car.
- In 2006, Ivujivik, Quebec resident Lydia Angiyou saved several children by fighting a polar bear until a local hunter shot it.
- In 2006, in Tucson, Arizona, Tom Boyle watched as a Chevrolet Camaro hit 18-year-old Kyle Holtrust. The car pinned Holtrust, still alive, underneath. Boyle lifted the Camaro off the teenager, while the driver of the car pulled the teen to safety.
- In 2009, in Ottawa, Kansas, 5 ft 7 in (1.70 m), 185 lb (84 kg) Nick Harris lifted a Mercury sedan to help a 6-year-old girl pinned beneath.
- In 2011, in Tampa, Florida, 6 ft 3 in (1.91 m), 295 lb (134 kg) University of South Florida college football player Danous Estenor lifted a 3,500 lb (1,600 kg) car off of a man who had been caught underneath. The man was a tow truck driver who had been pinned under the rear tire of a 1990 Cadillac Seville, which had lurched forward as he worked underneath it. The man suffered only minor injuries.
- In 2012, in Glen Allen, Virginia, 22-year-old Lauren Kornacki rescued her father, Alec Kornacki, after the jack used to prop up his BMW slipped, pinning him under it. Lauren lifted the car, then performed CPR on her father and saved his life. 
- In 2013, in Oregon, teenage sisters, Hanna (age 16) & Haylee (age 14) lifted a tractor to save their father pinned underneath. 
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 effluxion of dopamine in the central nervous system.
Superhuman strength is an ability commonly employed in fiction. It is the ability for a character to be stronger, tougher, more durable, and more physically powerful than humanly possible. Characters and deities with super strength have been found in many ancient mythologies and religions. Superhuman strength is a common feature across a wide range of media, such as novels, comic books, television, films, and video games.
Discovery channel produced a show called "Superhuman Showdown", one of the main classification was superhuman strength, in which five finalist were selected in the following category: Jimmy Bandera for his high-frequency voice, Dr. MAK Yuree for his leg power, Conard for his abdominal strength, Frannz Muellner for his arm strength and Jamal for his lung power.
Superhuman strength is used by several characters in fantasy and science fiction, with a variety of proposed mechanisms such as cyborg body parts or genetic modification and even telekinetic fields in science fiction, or divine or magical/supernatural sources in fantasy. A plethora of comic book superheroes and supervillains usually have a degree of super strength. The level of strength portrayed can vary greatly, from just outside the "normal" human range of the strongest weightlifters of a given size or muscle mass (e.g. unarmored Master Chief), to nearly or even unlimited (e.g. Hulk, Superman, Supergirl, Wonder Woman, Thor, Hercules and Goku).
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Physiologic and performance effects
• Amphetamines increase dopamine/norepinephrine release and inhibit their reuptake, leading to central nervous system (CNS) stimulation
• Amphetamines seem to enhance athletic performance in anaerobic conditions 39 40
• Improved reaction time
• Increased muscle strength and delayed muscle fatigue
• Increased acceleration
• Increased alertness and attention to task"
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