The Effects of 100% Oxygen on Soccer Players-Reply

In Reply.—  When performing medical research, a classic approach is to make use of a placebo-controlled, randomized, double-blind crossover study design. In such a design, as was used in the study by Winter et al,¹ the potential intervention is compared against a placebo and not against no intervention at all; this approach is used to control for the possible placebo effect of potential interventions. In the event that no differences are detected between the placebo and the potential intervention, then the potential intervention is not considered to be of benefit. Dr Gabel, however, suggests in his letter that should equivalent benefits occur with the placebo and the potential intervention, then the potential intervention should be considered to be of value. This logic does not take into consideration the likelihood that once it is known that the potential intervention is of placebo value only, it will, in essence, no longer