NY Times article on ibuprofen

After looking at racers’ blood work, he determined that some of the ultramarathoners were supplying their own physiological stress, in tablet form. Those runners who’d popped over-the-counter ibuprofen pills before and during the race displayed significantly more inflammation and other markers of high immune system response afterward than the runners who hadn’t taken anti-inflammatories. The ibuprofen users also showed signs of mild kidney impairment and, both before and after the race, of low-level endotoxemia, a condition in which bacteria leak from the colon into the bloodstream.

“For a lot of athletes, taking painkillers has become a ritual,” says Stuart Warden, an assistant professor and director of physical therapy research at Indiana University, who has extensively studied the physiological impacts of the drugs. “They put on their uniform” or pull on their running shoes and pop a few Advil. “It’s like candy” or Vitamin I, as some athletes refer to ibuprofen.