Control of the Exercise Hyperpnea: The Unanswered Question

At the first of what is now known as, the “Oxford Conferences,” Fred Grodins referred to the mechanism of the exercise hyperpnea, as “The Ultra Secret.” I have chosen to sub-title my presentation, “The Unanswered Question” (with apologies to Charles Ives) in the hope that even if the answer does not eventuate then at least the nature of the essential question will. But space constraints allow only one theme to be developed and that only for moderate exercise. And, as it is the “Oxford Conference,” I have chosen one initially adumbrated by one of Oxford's luminaries, C.G. Douglas; one, in my judgment, that is under-appreciated. In his 1927 Lancet review, Douglas (1927) describes an important study: “in which we followed in detail the behaviour of the breathing after the ingestion of a considerable quantity of sugar by a person at complete rest … The volume of air breathed per minute showed a perfectly definite rise and fall which ran closely parallel to the change in CO ₂ production, and the parallelism became still more obvious if the effective amount of air was calculated as distinguished from the total amount of air breathed.”