Painkiller use during marathons could be a serious health risk

You’re on the starting line raring to go, the starter gun sounds and you’re off, eager and determined to give it your best. There’s a bounce in your step and a smile on your face. Twenty-six and a smidge miles later and everything won’t seem nearly so bright! The marathon will have wreaked havoc on your body and muscles you didn’t even know you had will be screaming with pain.

It seems that the use of analgesics in endurance sports by amateurs and professionals alike, is becoming more widespread. Many athletes will consume over-the-counter (OTC) painkillers before competing as they strive to increase their performance and prevent pain.  Unfortunately many of these athletes will be self-prescribing with no idea about the potential health risks they are exposing themselves too.

The use of analgesics in endurance sports may cause potentially serious unwanted adverse events

The use of analgesics in endurance sports may cause potentially serious unwanted adverse events

A recent cohort study published in the British Medical Journal aimed to investigate the hypothesis that the drugs taken before sports may increase the incidence of cardiovascular (CV), gastrointestinal (GI) and kidney damage without lowering the pain during and after the exercise. The painkillers inhibit enzymes called cyclooxygenases and it is thought to be through this mechanism that they contribute to the development of adverse events (AEs). Cyclooxygenases regulate the production of prostaglandins, hormone-like substances that have a role to play in the contraction and relaxation of muscle tissue providing protective effects on CV, GI and renal function. By taking the analgesics the tissue protection that is usually provided by the prostaglandins may be suspended and this could trigger AEs.

Researchers asked participants in the Bonn marathon in 2010 to fill in an online questionnaire aimed at defining the use of analgesics and the relationship between the OTC analgesic use/dose and AEs during and after the race. 3913 out of 7048 runners returned their questionnaires and the incidence of AEs in the cohort of analgesic users was compared to non-users (controls). This is what they found:

  • 1931 respondents ingested analgesics before racing
  • Significantly more women (61%) took analgesics than men (42%)
  • The three drugs most frequently used were aspirin, diclofenac and ibruprofen
  • There was no significant difference between the premature race withdrawal rate in the analgesics cohort and the controls
  • Race withdrawal because of GI AEs was significantly more frequent in the analgesics cohort than in the control
  • Withdrawal because of muscle cramps was rare but was significantly more frequent in controls
  • The analgesics cohort had an almost 5 times higher incidence of AEs (overall risk difference of 13%) and this incidence increased significantly with increasing analgesic dose
  • Nine respondents reported temporary hospital admittance: 3 for temporary kidney failure (post ibruprofen), 4 with bleeds (post aspirin) and 2 with v=cardiac infarctions (post aspirin)
  • None of the control group reported hospital admittance


  • No information was available for half of the marathon participants, as they did not return their questionnaires
  • Confounding factors such as body mass index and use of other drugs were not investigated

The authors concluded:

We conclude that the use of analgesics before and during endurance sports may pose a serious health problem that should be addressed.  Our investigation has also shown a worrying lack of education about these AEs within the participants of the Bonn 2010 marathon, which may highlight a larger problem if mirrored in the endurance sport community in general.

So it looks like the best way to deal with the pain and discomfort during and after a marathon is to grin and bear it.  Oh and as we all know good training helps in the long run!


Michael Küster, Bertold Renner, Pascal Oppel, Ursula Niederweis, Kay Brune Consumption of analgesics before a marathon and the incidence of cardiovascular, gastrointestinal and renal problems: a cohort study BMJ Open 2013;3:4 e002090 doi:10.1136/bmjopen-2012-002090