Despite a growing body of evidence that taking NSAID (non-steroidal anti-inflammatory drugs) painkillers before, during, or after exercise can lead to a host of health problems, surveys show anywhere from 50 to 70 per cent of endurance athletes (recreational and professional) pop ibuprofen on a regular basis.

Taking painkillers during training and events, especially in high doses, can lead to woes like leaky small intestines, impaired kidney function, higher levels of tissue-damaging oxidative stress, slower recovery, and maybe even a higher risk of cardiac arrest.

But if you’re still supplementing hard workouts with ibuprofen to pre-empt or prevent pain, take note that the latest study shows it may also interfere with muscle development.

To investigate the impact of NSAIDs on strength training, researchers had a group of 31 men and women, ages 18 to 35, perform heavy leg work in the gym two to three days a week for eight weeks. Fifteen of them took the maximum daily dose (1200 mg) of ibuprofen and 16 took a small daily dose (75 mg) of aspirin over the same period. At the end of the study, the low-dose aspirin users had increased muscle size twice as much as the ibuprofen poppers. They also saw more strength gains.

Yes, that’s a whole lot of over-the-counter painkiller use, and the researchers are clear that heavy, chronic usage seems to cause the most trouble. However, other negative effects such as gut damage and blunted recovery have been found with much lower doses and less frequent usage.

Medical experts increasingly agree that it’s wise to reconsider using OTC painkillers as part of your regular training, racing, and workout plan, unless you’re actually injured and really need them. Even then, try to stick to low doses.