How top athletes dip into usually inaccessible reserves of strength and endurance

At the 1983 World's Strongest Man competition, in Christchurch, New Zealand, a fresh-faced Canadian powerlifter named Tom Magee, later known as MegaMan during a brief World Wrestling Federation career, deadlifted 535 kilograms of local cheddar cheese – "enough," the television commentator deadpanned, "to fill an awful lot of mousetraps."

Thirty-five years later, that feat remains the heaviest deadlift in the books. Yet local news sources regularly report seemingly greater performances out in the real world – such as that of Nick Williams, the Newfoundland man who lifted a four-wheel-drive vehicle high enough for a young boy to be pulled from under its tires in 2015, or Charlotte Heffelmire, a 19-year-old Virginian who hoisted a burning GMC truck off her pinned father that same year. What Mr. Williams and Ms. Heffelmire may have tapped into is the stuff of legend – a well of superhuman strength that can only be drawn on in moments of crisis or extreme passion.

So could Tom Magee have put the record well and truly out of reach if there had been a helpless child trapped under all that cheese?