In a double-blind , placebo-controlled study , 102 firefighters were randomized to receive daily therapy ( 81 mg aspirin or placebo ) for 14 days before and a single dose ( 325 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 ) .