Several other European scientists must also be mentioned, not only because of their contributions to the exercise physiology, but also because their names are commonly used in a discussion of exercise physiology. J.S. Haldane did some of the original work on the role of CO2 in the control of berating. Haldane also developed the respiratory gas analyzer that bears his name (15) .C.G. Douglas did pioneering work with Haldane in role of O2 and lactic acid in the control of berating during exercise, including some work conducted at various altitudes. The canvas- and – rubber gas collected bag used for many years in exercise physiology laboratories around the world carries Douglas’s name. A contemporary of Douglas, Christian Bohr of Denmark, did the classic work on how O2 binds to hemoglobin. The “shift” in the oxygen – hemoglobin dissociation curve due o the addition of CO2 bears his name. Interestingly, it was Krogh who did the actual experiments the enabled Bohr to describe his famous “shift”