Hill was born in Bristol, England, on September 26, 1886. His father, a timber merchant, abandoned the family when Hill was three, leaving his mother to educate the boy and his younger sister. After completing his primary education, Hill earned a scholarship to Trinity College, Cambridge, which he entered in 1905. At Trinity, Hill majored in mathematics and completed the usual three-year course in two years. In the process, however, he found that he was more interested in physiology than in mathematics.

After graduating in 1909 with a degree in natural sciences, Hill began research on frog muscle at the Cambridge Physiological Laboratory. At the time, muscle research was proceeding in a number of directions. Walter Fletcher (1873-1934) and Frederick Gowland Hopkins, for example, had earlier studied the chemical changes that occur in muscles during contraction, discovering the role of lactic acid in that process.

Hill, however, decided to forego the study...