Participants treated with acetaminophen extended release (ER) reported a significantly greater decrease in the primary endpoint of average change from baseline in muscle soreness on the day of the marathon (day 1) than did placebo. In addition, the adjusted mean average interference with sleep was significantly lower for acetaminophen ER than for placebo. -A Randomized, Placebo-controlled Trial of Acetaminophen Extended Release for Treatment of Post-marathon Muscle Soreness.
BUT WAIT! Read this comprehensive review by Jonathan Savage on the NEGATIVE impact of non-steroidal anti-inflammatories on post run recovery and healing.
MY COMMENT: Let nature take it's course after a marathon, have a few beers, and forego the tylenol.