Awareness around the health benefits of regular exercise is increasing, as is participation in mass community-based endurance sports events, in particular marathon running. However, prolonged moderate- to high-intensity exercise such as distance running transiently increases the risk for moderate and serious medical events in a variety of organs in the body. Older participants, those less accustomed to exercise, and those with known chronic diseases, are at higher risk of this happening. The use of chronic prescription medication has also been identified as a factor that increases one's risk for developing medical complications during endurance sport. Its use during exercise may increase the risk of cardiovascular complications, severe fluid and electrolyte abnormalities, acute renal failure, rhabdomyolysis, exertional heat stroke, gastrointestinal bleeding, tendon injuries and muscle cramps. Specifically, beta-blockers, antiarrhythmic drugs, anticoagulants and antiplatelet drugs, beta2-agonists, psychoactive drugs, narcotics and stimulants have been found to be associated with an increased risk of cardiovascular side effects during exercise.

Getting an idea of how many participants in these endurance events use prescription medication, is important for the race medical team to be able to identify those that may be at higher risk of having a medical complication on race day. Researchers at SEMLI studied runners in the Two Oceans Marathon races (21.1km and 56km) over a 4-year period to find this out. They report that 1 in 8 entrants used chronic prescription medication on a regular basis to treat chronic medical conditions or injuries, and that use was higher in older participants, females and in the 21.1 km race entrants. Blood pressure lowering and cholesterol lowering medications seemed to be the most commonly used, followed by asthma medication and medications to treat anxiety/depression. Furthermore, they identified which subgroups of race entrants more commonly use specific types of chronic prescription medication and discussed the potential side effects of these medications. Not only can this information assist medical teams to prepare for the medical incidents that will occur on race day in order to give the best medical care possible, but it could also improve broader strategies to prevent and manage medical complications experienced by runners during endurance exercise. 

Chronic prescription medication use in endurance runners: a cross-sectional study in 76,654 race entrants – SAFER XV.  The Physician and Sportsmedicine, 2021 Mar 2;1-10

Marcel Jooste, Martin Schwellnus, Nicola Sewry, Dina C (Christa) Janse Van Rensburg, Dimakatso A. Ramagole, Sonja Swanevelder e and Esme Jordaan

https://pubmed.ncbi.nlm.nih.gov/33535862/