I can only speak to this from the perspective of the under the car, but there is something that happens. When my lovely non-strength trained 5'10 125 lb 42 y/o bride tried to lift our '94 land rover discovery off of me she was not completely successful. It rocked off the jack stands and was sitting on the rear brake discs which left enough room for about 2/3 the depth of my chest between the steel frame rails and the driveway. She was able to lift on the wheel well opening enough to take some pressure off until the neighbor arrived w/ a floor jack. Adrenaline is really cool because neither of us felt our injuries until later that night. me--bruising and intercostal muscle strain for a month. her--torn/bruised quad from resting the wheel well on it. divot still there 3 years later. Fun stuff. all that to say, I think she could have made the lift if we had an old vw beetle instead of the disco. And I'm not allowed under the cars anymore.
"Hysterical strength" or not, I think our experience comports with Dr. Zatsiorsky's findings. Anyone want to trade a land rover for a 'beetle?