Normally athletes are being told to be tested after a competition. This means that Doping Control Officers will collect urine and blood which will be sent for analysis.
In recent years samples has been collected before competition. The reason for this is that there are some Performance Enhancing Drugs that have a very short window to be detected. That short window could be the length of a tennis match and sometimes even shorter.
According to the World Anti-Doping Code (Code), an "in competition" test can be carried out during the period from 23:59 on the day before a competition through the end of such competition and the sample collection process related to such competition. This practice has been defined in the Code since 2021 (Sources: Sport Integrity Australia and Swiss Sport Integrity).
Disclaimer: In this article I am using the recent incident at the Davis Cup match in Malaga, Spain, where the Serbian tennis-player Novak Djokovic was told to be tested before the match. The Serbian refused and could now be risking a long ban from the sport. Even though I am using Djokovic as an example, it does not mean I believe the current world number one is using PEDs - and specifically blood doping. I am just using the incident and the prohibited method as an example.
In an article in the British newspaper Mirror, Novak Djokovic is outraged because he was told to be tested before competition. He claims this testing regime breaks his pre-match routines.
There is a reason why sports organizations now are starting to test athletes prior to their competition. One being that they can according to the rules. And the second is to test athletes who may be using a substance that is hard to detect after the competition, but that would've enhanced the performance of the athlete during the competition.
Low dosages of blood doping for instance has a very narrow window for detecting. And the benefit of blood doping is that an athlete has more endurance - which could be beneficial in a tennis match that can last for hours.
Studies has shown that blood doping can improve performance by up to 3% with blood doping. According to a study at the Department of Nutrition, Exercise and Sports at the University of Copenhagen, reveals that even a small blood transfusion of only 135 ml or red blood cells, can improve performance in cycling and other endurance sports.
What can happen to Djokovic now? It is clearly defined in the World Anti-Doping Code - International Standard Testing and Investigations it is possible to be tested before the actual event when the athlete participates in a competition. Therefor it would not surprise me if the Serbian tennis-star will be provisionally suspended until a hearing. By refusing to be tested before the event, Djokovic violated the article 2.3 in the World Anti-Doping Code. The headline for article 2.3 is "Evading, refusing or failing to submit to sample collection by an athlete".
Some could say that he did participate in a sample collection after the match, but as stated above. If the athlete has used PEDs that may benefit him or her during the match, it will in some cases be hard to detect any substance after the match.
What shall the International Tennis Federation, The International Tennis Integrity Agency and the World Anti-Doping Agency do now? I believe this is an opportunity for any agency who is trying to make sport cleaner and more fair to tell that no athlete is above the Anti-Doping Rules. It may be that you have not read the anti-doping rules, or that no one around you has either. But when you are at the level Djokovic is, where participating in sport is your job, then it is also your duty - or the duty of the people around you - to be up to date on the rules protecting clean athletes.
In the Anti-Doping Database we currently have registered close to 600 athletes who has been banned for refusing to be tested. Most of the cases results in long sanctions. 231 athletes has been banned for two years and 211 has been suspended for 4 years.