Covid-19 may have made things worse, says Ross Tucker, a South African sports scientist. Since the effects of PEDS last much longer than the drugs stay in an athlete's body, elite competitors are subject to testing even when they are not competing. But travel bans and lockdowns have disrupted that system. Between covid-19, the fallout from Russia and a steady drip of other doping cases, every performance in Tokyo—even those by clean athletes—will take place under a faint but ineradicable cloud of suspicion. As Kyle Chalmers, an Australian swimmer who won the 100 metres freestyle at the 2016 summer Olympics in Brazil, put it last year, "I can probably not trust half the guys I'm competing against."
No one knows how many athletes still dope. But a glance at the headlines suggests it is far from rare. In 2019 Nike, a sportswear company, closed down its much-publicised Oregon Project, a training camp for elite runners, after Alberto Salazar, the head coach there, was given a four-year ban for doping. (Mr Salazar is appealing.) Kenya is famous for the dominance of its middle-and long-distance runners. These days that reputation is looking tarnished. The Athletics Integrity Unit, which polices anti-doping in athletics, lists 68 Kenyan runners currently banned from competing, including Wilson Kipsang, a former Olympic medallist and world-record holder. Nor is it just athletes who are punished. In March Richard Freeman, a former doctor to Britain's all-conquering 2012 Olympic cycling team, was struck off by regulators for obtaining steroids in 2011 (Dr Freeman is appealing).
When it comes to hard numbers, official statistics provide a lower bound to what is happening. In 2018, the most recent year for which there are data, 0.6% of the 263,519 blood and urine samples analysed by WADA-affiliated laboratories led to sanctions. Doping was more common in some sports—and some countries—than others. But WADA's numbers reflect only those who get caught. David Howman, once WADA's chief operating officer, says he thinks the real figure in elite sports might be more than one in ten—which would imply that over 90% of dopers were getting away with it. By and large, he says, only the "dopey dopers" get caught.