Originally Posted by
Diane
Out of curiosity I Googled, so here you go.
Players are tested for banned substances in accordance with the guidelines of the World Anti-Doping Code (from WADA, the World Anti-Doping Agency).
New provisions in the World Anti-Doping Agency (WADA) program that kicked in 2009 require top players to provide testers with their exact location for one hour every day of the year. Previously, they only had to do so during the six-week out-of-competition period in November and December.
The so-called "whereabouts" provision applies to the top 50 men's and women's singles players and the top 10 men's and women's doubles players. Tennis' anti-doping program is run by the International Tennis Federation, which adheres to the WADA anti-doping code.
If a player misses three drug-testing visits in an 18-month period, he or she is subject to sanctions, suspensions or even a lifetime ban.