Gee … if biomarker testing is so terrific, then why aren’t all anti-doping tests designed to look for biomarkers?
Remember that a biomarker test measures the effect that the performance-enhancing drug has on the biomarker. It’s possible that the same effect might be produced by something other than the performance-enhancing drug. Q: Like my black-and-blue mark being caused by the car door. A: Yes. Going back to our example of blood doping, we said that a low reticulocyte count might be a biomarker for blood doping. But there are other things that might cause a low reticulocyte count: for example, getting sick, or moving from a high to a low altitude. There’s also a certain natural variation in most biomarkers. In order for the HGH test to be valid, the scientists have to find a biomarker measurement that they can confidently link to HGH use – and only to HGH use.
