Mass, movedEvery exercise moves mass: a barbell, a boat, your own body. A jump lifts you. A squat lifts the bar. A run carries you forward. Mass moved through a distance is work.
At some speedAnd it moves at some speed. Work done each second is power, in watts. Keon Johnson's 41.5-inch standing vertical: 1,869 watts for under half a second. Tigst Assefa's 2:15:41 marathon: 336 watts for over two hours.
1906, Harvard. 1925, Southampton.The engineer Arthur Kennelly, once Edison's chief assistant, put the records of horses, runners, walkers, rowers, swimmers and skaters on one log chart, and each sport fell along a near-straight line. In 1925 the physiologist A.V. Hill, a Nobel laureate, plotted athletic records against a log scale of time and read in them the limits of working muscle.
Every world recordA century on, FITNDEX puts every record, every event and every body on one scale. Plot every world record here by power and time and one pattern appears: one frontier, the best at every duration or longer. Each badge on it is the number the world knows. See it on the chart ›
One scale for timeScore the same records on FITNDEX relative and that frontier barely moves: 691 to 693 for men, 591 to 604 for women. Half a second or two hours: almost flat. See it flat ›
Why it worksTime is the only thing FITNDEX reads on its own scale. Everything else is physics: the mass, how far it moved, how fast.
Kennelly AE, Proc Am Acad Arts Sci 1906;42:275-331. Hill AV, Nature 1925;116:544-548.