Overall, Breuning was in good health almost all of his life. His weight was around the same for the last 50 years of his life, . Because Breuning was , his body mass index was around 19. For years Breuning took a baby aspirin every day, but he eventually gave that up, stating that he did not need it; from there on he took no medication. Breuning believed another key to his longevity was keeping his mind and body active, not retiring until the age of 99. He performed daily calisthenics almost to the end. In his final years he could not read well because his eyesight was badly impaired by cataracts, but he kept himself occupied mentally by listening to the radio.