Experts say there's little evidence meldonium aids performance

(Photo: Jayne Kamin-Oncea-USA TODAY Spor)Maria Sharapova is the most noteworthy athlete to have failed a drug test for meldonium, but in the month since the tennis star revealed her use of a drug that she contends is for medical reasons a slew of other top athletes have been implicated.

They include fellow Russians Yuliya Efimova, a four-time breaststroke world champion, and Nikolai Kuksenkov, the country’s best male gymnast. In all, 140 athletes have tested positive for meldonium in the three months after it was banned on Jan. 1, according to a World Anti-Doping Agency spokesman.

But as the tally of failed tests increases, critics are raising questions about its performance enhancing…