The World Anti-Doping Agency (WADA) recently revealed that 109 of 208 soccer players tested positive for clenbuterol during the Under-17 FIFA World Cup held in Mexico in July.

Clenbuterol is still used illegally by some Mexican farmers to bulk up cattle and is a banned substance that can cause an increase in aerobic capacity.

WADA issued a statement last week urging all athletes in Mexico to “exercise extreme caution with regards to what they eat and where they eat.”