The global reduction in travel and human contact over the last year may have played an important role in battling COVID-19 but it has added a new layer of complexity to fighting the doping cheats ahead of the Tokyo Olympics.
For more than a year, the anti-doping policemen of the sports world have been battling the restrictions imposed by the pandemic.
Social distancing, travel restrictions and the basic lack of knowledge about confirmed participants have all created problems for testers ahead of the Games which were originally scheduled for July-August 2020 before being pushed back a year.
For a part of last year, when the sports world shut down in March and April, there was effectively no testing.
It resumed when competition started again in the summer but under a range of restrictions as each nation imposed their own Covid regulations.
"We test around 50 sports almost all over the world, so it's a logistical nightmare," explained Benjamin Cohen, the secretary general of the International Testing Agency (ITA), which leads the anti-doping programme for the International Olympic Committee (IOC).
One problem is the daily need to stay up to date with the regulations of each country.
"The testing department constantly has to update the list of national measures, for example to integrate the difficulty of collecting blood samples in certain countries due to the distancing rules," said Cohen.
Another problem is the practical difficulty that testers face when trying to do their job.
"We had a DCO who went to Dubai," Travis Tygart, the head of the American agency USADA, told AFP.
"And all the constraints they had to go through… take a Covid test, demonstrate they were negative, quarantine in the hotel for a period of time.
"To then be at the event to do the testing. It was above and beyond anything we could have foreseen."
The role of national anti-doping agencies has, by necessity, been strengthened. But not all are blessed with similar resources and nor are they endowed with the same integrity and zeal to weed out the cheats.
"The big problem is, are we going to have a repeat of what we had in Rio?" asked Tygart, who wants all test results to be published on the internet.
"In Rio there were 1,913 athletes in 10 high-risk sports that had no tests heading into Rio. That has to change.
"It can't be 'Trust us, we're going to do it right'. We need to see."
The postponement of certain qualifying events, prolonging the uncertainty over the participants in the Games poses another problem for testers who are left to monitor many more athletes than they can handle.
"The idea is to cast a wide net before and, as we get closer to the Olympics, the 'long list' becomes a short list, and we start to know the names of those who are going," says Olivier Niggli, director general of the World Anti-Doping Agency (WADA).
But even before the pandemic, an increase in testing was struggling to keep step with the science and ingenuity of the doping cheats.
According to WADA's annual reports the rate of positive controls amounted to one to two percent while studies showed a level of cheating at least 10 times higher.
To bridge this gap, the fight against doping has recently developed in two complementary directions — by strengthening its data analysis and by opening its door to whistleblowers.
"We will continue to process information, track locations, and monitor the mass of data at our disposal, including the biological passport," said Nicole Sapstead, the boss of the UK anti-doping body, in March 2020.
Adopted since 2008 in cycling and 2011 in athletics, the biological passport offers long-term surveillance of athletes, no matter what the health restrictions.
Rarely sufficient to prove cheating on its own, it is decisive for targeting tests.
"The key will be artificial intelligence and automation" to better process this mountain of physiological data, said Cohen.
At the same time, WADA, which was unable to exploit the first reports of Russian doping in 2010 because its investigations were not yet confidential, in 2017 launched "Speak Up!", an anonymous platform for whistleblowers.
Many anti-doping players have followed suit, from the Athletics Integrity Unit to French and German anti-doping agencies, including the ITA, which has posted "Reveal" online last February.