Meyerhof, Otto Fritz (1884-1951), a German-born American biochemist, shared the 1922 Nobel Prize in physiology or medicine for his research into oxygen consumption by muscles, and the relationship of oxygen consumption and the metabolism of lactic acid (a chemical produced in the body by muscular activity) and carbohydrates within the muscle. Meyerhof shared the prize with English physiologist Sir Archibald Vivian Hill, who was honored for his discovery relating to the production of heat in the muscle.

A pioneer in the field of biophysics, Meyerhof also researched the effects of different chemicals on oxidation processes (chemical reactions in which a substance loses electrons).

Born in Hanover, Germany, Meyerhof received an M.D. degree from the University of Heidelberg in 1909. He worked in a medical laboratory there until 1912. He became an assistant professor at the University of Kiel in 1918. His early work involved cellular respiration. However his interest turned to the study of the chemical events, and heat changes during muscle contraction.

In 1919, in experiments on energy metabolism, he proved the existence of a quantitative relationship between the amount of glycogen used by a muscle cell and the amount of lactic acid that was produced. He demonstrated that the process could occur without oxygen, called anaerobic glycolysis. His experiments also showed that when the muscle subsequently relaxed, about one-fifth of the lactic acid was oxidated and reconverted to glycogen, thus beginning the cycle again.

In 1924, he moved to Berlin to work at the Kaiser Wilhelm (now the Max Planck) Society in Berlin. In 1929, he became head of the newly founded Kaiser Wilhelm (now the Max Planck) Institute for Medical Research in Heidelberg.

In 1938, anti-Jewish policies caused Meyerhof to leave Germany. He went to Paris, where he served as director of research at the Institut de Biologie Physico-chimique. When the Nazis invaded France in 1940, he emigrated to the United States. He was appointed research professor of physiological chemistry at the University of Pennsylvania in 1940, where he remained until his death from a heart attack in 1951.