In the heaviest dead lift recorded, British weightlifter Andy Bolton lifted 457.5 kilograms (1,008 pounds) from the floor to his thigh.
What is the maximum weight a human could ever lift? Todd Schroeder at the University of Southern California in Los Angeles thinks we are already close to the maximum. "If you look over time at the records for maximal lifts, they have crept up but are starting to plateau," he says. "Today's weightlifters, including those that use steroids, are near the limit of human potential."
It is the muscles that set the limit. When something does give way, it is usually the muscle fibers that tear, often near the tendon. It is control of the muscles that gives weightlifters their advantage. The body has natural inhibitory mechanisms designed to keep us from hurting ourselves by trying to lift too much. These work by controlling how many muscle fibers are activated at any one time. Weightlifters learn to suppress these signals, enabling them to use a larger fraction of the muscle's potential in lifting.
The key to success is training and genetics plays a role. Short limbs favor strength and some people have more muscle fibers than others.