I find your discussion of performance-enhancing drugs (Nature 487, 287–289; 2012) disrespectful to the millions of elite and sub-elite athletes who rely solely on training to reach their goals. In reality, most of these drugs do not create “superhuman athletes” but allow athletes to take short cuts in training or to recover faster from injury.

The sport of running has been plagued by doping for years, and a slew of positive tests has been reported in recent weeks. But to suggest that doping should be embraced because drug-testing efforts are a losing battle is absurd. For every performance-enhancing-drug pragmatist, there are many who would rather see stricter testing regimens and harsher penalties for offenders.

Science does hold promise for future athletes wanting to break today's barriers, but the realms of exercise science, sports psychology and nutrition are likely to have more bearing than pharmaceuticals and genetics (Nature 487, 297; 2012).