Is getting your one rep max either from a calculator or by doing it yourself self-deception at best? If a car fell on you and you cannot move it off you but your 1RM says you can, who is foolin who? In those strongman events, they move heavy stuff (many times their bodyweight) a long way not just a 1RM. Similarly in Oly lifting/Powerlifting its more than 1RM. What is the use of benching say 300lbs 1RM when you cannot bench your own bodyweight 8-15 times?