Hard evidence for a central governor is still lacking!

TO THE EDITOR: Reviewing evidence for and against a Central Governor that limits an individual’s maximal oxygen intake (2, 4), I am impressed that although this hypothesis was formulated some 11 years ago, it still lacks support outside the proponent’s laboratory. I note also that, perhaps because of an inappropriate test protocol, Noakes has consistently found difficulty in reaching first base in this area of research, the demonstration of an oxygen consumption plateau. In contrast, Ekblom and colleagues (2) have had no problems in this regard. Noakes (4) currently argues that a Central Governor is essential to prevent the development of a dangerous myocardial ischemia. However, anyone who has exercised older adults will know that a substantial proportion of such individuals manifest myocardial ischemia. Ultraendurance athletes also develop myocardial ischemia (3), and indeed may use this as a stimulus to cardiac hypertrophy. Does this imply that ultraendurance athletes and old people have carelessly broken their Central Governors? Noakes also cites (4), with apparent approval, the argument of A. V. Hill (3) that the Governor dissuades the heart from making an excessive effort that would reduce the oxygen saturation of arterial blood. Again, the weight of current evidence is that well-motivated athletes do reduce their arterial oxygen saturations (1). Moreover, it would be hard to imagine how the mechanism postulated by Noakes could evolve, since the forces of natural selection have not focused on the ability to perform a maximal oxygen intake test.