+1 The science consistently shows that the biggest predictor of performance advantage between individuals in physical sports is asigned biological sex at birth. You start taking about manipulating the human body with hormones and other substances that would usually be deemed as PEDs and it becomes a slippery slope of needing very frequent tesosterone level testing and different thresholds which are purely subjective in "leveling the playing field". I mean why even have men's and women's divisions at all if you're going to subjctively blur the lines of scientifically defined biological sex and be open to a "spectrum of genders" based on how one feels at a certain point in their adult life?