Superhuman burst of strength

First, have a browse through this article: HowStuffWorks "How can adrenaline help you lift a 3,500-pound car?"

Lots of people have heard feats of 'hysterical strength', situations where certain individuals demonstrate a tremendous, supernatural burst of strength (ie. a mother lifting a car to safe her baby from being crushed etc etc).

My question is this, the strength is generated when the individual experiences a high stress situation, so essentially something is triggered in the brain which in turn gives their entire bodily system the capacity to unleash this tremendous force. So, is it possible to replicate that amount of strength (or even a fraction of it) by willing it to happen?

It should be possible if you can make yourself feel like your life is in danger. Even slapping yourself hard will release some adrenaline, they proved this on Mythbusters (: