Google has a predictive search feature that suggests additional search terms as you start typing in a phrase. Number four on the list is not something I would expect to see.
In retrospect, however, it makes sense, because cycling and diuretics was in the news last month. Frank Schleck’s positive test for a banned substance during the Tour de France was big news in July. He tested positive for Xipamide, diuretic drug marketed by Eli Lilly under the trade names Aquaphor and Aquaphoril. While Xipamide is not specifically in the WADA list of banned drugs, the WADA prohibits “diuretics and other masking agents [including] Acetazolamide, amiloride, bumetanide, canrenone, chlorthalidone, etacrynic acid, furosemide, indapamide, metolazone, spironolactone, thiazides (e.g. bendroflumethiazide, chlorothiazide, hydrochlorothiazide), triamterene; and other substances with a similar chemical structure or similar biological effects.”
While diuretics themselves have no performance-enhancing effect, they can possibly mask the presence of performance enhancing substances like anabolic androgenic steroids. They increase urine production, and athletes (and their doctors) can use diuretics to try to flush some steroid residue from the body prior to a drug test.