I bet it’s that adrenaline thing, like when people lift up a car to free someone stuck under it. The body is a wondrous and mysterious thing.
Actually back in the 1960’s my dad was trapped under his car when it rolled and he was ejected. We never knew who did so, but there were two men that lifted the car sufficiently to get my father out. That was down near Tucumcari sp NM.
Interesting thing about some of those adrenaline stories, in many cases the superhuman strength violates the laws of physics regarding equal and opposite opposing forces.
For example a guy picks up a 3000lb car to lift it off a victim, yet we don’t find his shoes embedded in the asphalt from the resultant moment and strain rate on the pavement where he was standing.
I suspect there also may be some assistance from guardian angels in the fray. Likewise, just because a spirit shows up, we don’t want to quickly assume its the person who just passed away. It might also be angelic deception from those seeking any avenue to deceive.
What is much more wondrous than our body, is how God has made man in body, soul, and spirit and many of us do not even know what our spiritual gifts really are...