Magic Blood And Carbon-Fiber Legs | David Epstein | Scientific American | 5th August 2016

More on the contradictions of drug-testing in sports. “So, as the rules stand: having an incredibly rare gene mutation that boosts red blood cells is OK; training at altitude to boost red blood cells is OK; shelling out thousands of dollars to sleep in a tent that simulates altitude is OK; but injecting a drug, one approved for other medical uses that causes your body to act as if it’s at altitude — you’re a disgrace. How should we draw the line? Where does a fair advantage end and cheating begin?”