Hypoxia application in athletes is not doping

Abstract

Dear Editor,As a physiologist, I propose to consider the doping problemfrom the viewpoint of our discipline. A stay in hypoxia, beit continuous or intermittent, poses a challenge on the regu-latory potential of the organism like various other stimuliapplied during physical training. This usually leads toimprovements of functions after acclimatization if the chal-lenge does not exceed the adaptive capacity of an organism;for a permanent stay, the limit for humans is an altitude ofapproximately 5,000 m above sea level. In most athletes,the health problems suggested by Lippi and Franchini(2009) may be prevented by avoiding too rapid or too highascents to real or artiWcial altitudes.In contrast, most doping manipulations including eryth-ropoietin injections and blood infusions disturb the regula-tion usually securing homeostasis and thus health in theorganism. This is diVerent from clinical medicine wherethese measures are used to re place lost functional propertiesor regulations. Disturbing the physiological equilibrium canimpose risks to individuals, although the incidence of thishas not been formally documented. The often proposedabolition of any doping control would exaggerate the risks.The suggestion by Sanchis-Gomar et al. (2009) thatintermittent hypoxia after erythropoietin doping increasesthe reticulocyte number thus inXuencing the OV score asindirect measure of blood doping (Parisotto et al. 2001) isonly based on a small animal experiment and is still some-what hypothetical. But it raises concern that a rather simpleparameter like a score considering only two quantities(hemoglobin concentration and reticulocyte number) in acomplex regulatory network might be not fully reliable fora clear decision about doping and thus unnecessarily castssuspicion on an athlete. A possible solution for the problemof eVects of hypoxia on such scores is a correction factordiscussed by Ashenden et al. ( 2003); surprisingly this paperis not cited by Sanchis-Gomar et al.Considering these various aspects, it is not justiWed toinclude every treatment with partly equal eVects like blooddoping and inXuencing similarly a simple score in theprohibition list.