A12. Testosterone is an excellent proxy for biological sex and a valid basis for an eligibility rule for the women’s category for the following reasons:
- Testosterone is the primary driver of the sex differences in athletic performance;
- Sport already tests for and monitors testosterone levels as part of the normal anti-doping process; and
- Different sex testing protocols are more intrusive and, in some cases, less accurate.
No other single criterion so comprehensively addresses sport’s and society’s concerns abo