Hill, Sir Archibald Vivian (1886-1977), was an English biologist who studied how muscles contract during movement and exercise. For this research, he shared the 1922 Nobel Prize in physiology or medicine with German biologist Otto Meyerhof. Hill contributed to the development of biophysics, the field of biology that applies the tools and techniques of physics to study life processes.
Experimenting with frogs, Hill used a sensitive device called a thermopile to show that heat is produced when muscles contract. He was able to measure changes in temperature less than 0.005 degree Fahrenheit (0.003 degree Celsius). These changes lasted only a few hundredths of a second in individual muscle fibers. Hill and other scientists then could calculate the exact chemical reactions that take place to produce muscle contraction.
When muscles work, oxygen is combined with food to supply the energy needed for contraction. This process produces heat and lactic acid, a waste product, that builds up in the muscle tissue. Hill believed that the lactic acid caused the fatigue and soreness that occurs in muscles after exercise. The lactic acid disappears as muscles recover during rest. Hill demonstrated that oxygen is also used to eliminate lactic acid during this recovery phase. Hill used the term oxygen debt to explain the heavy breathing of athletes after intense activity, such as running a race. He thought that runners build up so much lactic acid that they must continue to breath hard many minutes after a race to get enough oxygen for their muscles to recover quickly. However, scientists now know that muscle cells actually break down lactic acid to produce additional energy during exercise and that lactic acid is not the cause of muscle soreness or fatigue.
Hill was born in Bristol on Sept. 26, 1886. He studied mathematics and physiology (the science of bodily functions) at Cambridge University, graduating in 1909. During World War I (1914-1918), he served in the British Army and helped design and improve antiaircraft weapons. He was a professor at Manchester University from 1920 to 1923. He then became professor of physiology and biophysics at University College in London. In the 1930’s, Hill helped found the Society for the Protection of Science and Learning, an organization that helped Jewish scientists in Germany escape Nazi oppression. He was knighted in 1918. He died on June 3, 1977.
See also Muscle (How muscles work) .
