In a double-blind , placebo-controlled study , @ firefighters were randomized to receive daily therapy ( @ mg aspirin or placebo ) for @ days before and a single dose ( @ mg aspirin or placebo ) following exercise in TPC resulting in four potential assignments : aspirin before and after exercise ( AA ) , placebo before and after exercise ( PP ) , aspirin before and placebo after exercise ( AP ) , and placebo before and aspirin after exercise ( PA ) .