feats of human 'super strength' are generally called
Hysterical Strength, and are
generally one-shot, uncontrollable bouts of extreme strength. it's very difficult to induce this kind of strength intentionally, except for using
drugs. the problem with it, is the human body isn't designed to be that strong, and this kind of strength can actually result in self-injury, torn
muscles, ligaments, etc.
I have actually experienced this kind of strength before, at least once, possibly twice. the first time was at my last job, when I caught roughly 1500
pounds of windows that were about to fall sideways off a truck and onto another individual. I was helping load them onto the truck off of a dock, onto
the back of a flat-bed truck. the windows (wood composite frame windows, shipped complete with glass in them, meaning they were extremely heavy) were
sitting straight up, with no support to lean against, secured by shipping straps criss-crossed overtop of them. this is an extremely STUPID way to
move windows, by the way, but the customer insisted (and the windows were technically his, so we couldn't hold them since he'd already paid).
anyway, his wife was there, and when the guy who the windows belonged to gave them a good shake to make sure they were secure, they all started to
fall to one side, towards the guy's wife. i happened to be standing on the same side, on the shipping dock, and I grabbed the window that was at the
edge of the truck (the first one falling) with one hand, and braced myself on the edge of the dock with the other. by all rights, I shouldn't have
been able to hold them (the shipping straps had released and weren't holding them up, at this point), and that woman should have been crushed to
death under a shower of broken glass, but I managed to hold the windows long enough for two other guys to run over and help me.
the second time is more questionable, and involves pushing a car up a sheer icy hill in winter.
both of these times, I was incredibly sore afterwards, for days, and had several pulled muscles, even though I'm a fairly strong and muscular guy to
begin with. Humans aren't designed to be that strong ALL the time.
in any event, I don't think there are any literal supermen out there, but there are people who are exceptional in little ways everywhere. none of
them are as extraordinary as comic book heroes, however.