A new study published last week in British Medical Journal: Open adds more evidence to the dangers of taking pain relief medication before a long running event.
German researchers studied 3900 runners of the Bonn Marathon and Half Marathon, asking them to report their pain medication use before the event and any adverse events experienced during or after the race.
Half of the runners reported using pain medication before the race, with the most popular drug being diclofenac (which isn’t often used in the United States), followed by ibuprofen and aspirin.
Researchers found that those runners who took pain medications experienced significantly higher rates of stomach/GI cramps, GI bleeding, heart-related problems, and bloody urine compared to those who didn’t take any medications. All serious events requiring hospital visits (though only 9 in number) were in the pain medication group, with the three instances of temporary kidney failure in those who had taken ibuprofen.
Not surprisingly, but also not documented previously, the higher the medication dose taken before racing, the more likely it was that adverse events occurred. But even at low doses, the risk of adverse events was higher in users than non-users.
Researchers also found that pain medication didn’t seem to offer much benefit to offset the risks. While those in the medication group had slightly fewer muscle cramps during the race compared to non-users, they didn’t experience less soreness or joint pain. In fact, medication users had higher rates of soreness and pain after the event than non-users.
While it’s not perfectly understood why pain medication may lead to adverse events during endurance running, it could be that such medications inhibit the production of prostaglandins, which have hormone-like qualities that help protect tissue from damage. Inhibiting prostaglandin production could make tissue damage to the GI tract, heart, and kidneys more likely, especially under the stress of a long athletic event.
Taken together, these results are pretty compelling that taking pain medication before long endurance running events likely provides little benefit and can come with some real risks . While these results can’t be directly transposed to ultramarathons, it’s not too far fetched to think that the risks of using pain medications before or during such events would at a minimum match, and possibly exceed, those detailed in this study.