1. In order to benefit from the reduction or elimination of the sanction for specified substances, the athlete has to provide corroborating evidence, in addition to his or her word, which establishes the absence of intent to enhance sport performance or mask the use of a performance enhancing substance. Such evidence has to be provided “to the comfortable satisfaction” of the hearing body, i.e. to a level greater than the mere balance of probabilities, but lower than proof beyond a reasonable doubt. For nonspecified substances, on the other hand, the athlete has to establish, by balance of probabilities, that he bears No Significant Fault or Negligence, i.e. that his or her fault or negligence, when viewed in the totality of the circumstances, was not significant in relationship to the anti-doping rule violation. As a common condition for specified and non-specified substances, the athlete has to establish how the prohibited substance entered his or her body. Such evidence has to be given by the athlete by balance of probabilities, that is to say, that the occurrence of the circumstance on which it relies is more probable than its non-occurrence.
2. In connection with proving the absence of intent to enhance sport performance, (i) the evidentiary standard is higher than the mere balance of probabilities; (ii) the “corroborating evidence” cannot be limited to the athlete’s words, and (iii) no ex post evaluations of the effect of the prohibited substance on the sporting performance are allowed.
3. An athlete is highly negligent when failing to consult a doctor, or even make any kind of control, before the use of a product he has bought. He is also negligent when using a product for a purpose for which it was not prescribed.