How does doping affect athletes' health?

Euronews

26-07-2025

This weekend promises to be an exciting one for sports fans.
The World Aquatics Championships in Singapore begin their third weekend of competition, while the prestigious Tour de France concludes on Sunday, marking the end of one of cycling's greatest events. To cap off the weekend, the UEFA Women's EURO 2025 final takes place on Sunday evening in Basel, Switzerland, with world champions Spain facing European champions England.
These three major events comprise different sports in different parts of the world, but they are united by one common aspect: anti-doping.
Athletes participating in these events are closely monitored to ensure that these competitions remain free from banned substances listed on the World Anti-Doping Agency (WADA) Prohibited List.
In the last three episodes of Euronews Next's podcast Euronews Tech Talks, we've explored how complex it is for anti-doping authorities to detect doping and the reasons why some professional athletes resort to it.
But what exactly are the physical health risks associated with performance-enhancing drugs?
Some preliminary remarks
Before exploring the health risks associated with some of the most commonly used doping substances, there are some important points to make.
To be included on the WADA Prohibited List, drugs and practices must fulfil at least two out of three criteria: they have the potential to enhance or do enhance sport performance; they represent an actual or potential health risk to the athlete; they violate the spirit of sport.
This means a substance may only be performance-enhancing and violate the spirit of sport, or it may pose no actual health risk but a possible one.
2. Doping is a tricky research field
In episode 50, Francesco Botrè, Director of the WADA-accredited anti-doping laboratory in Rome, highlighted that researching doping is complicated because studies must respect ethical and health safety criteria. For example, researchers cannot administer high doses of certain banned substances to study participants due to potential health risks.
3. Research on doping is relatively recent
As noted in episode 51 by Dominic Sagoe, Professor of Psychology at the University of Bergen, research on doping is relatively recent, and the substances athletes use are also new, making it difficult to assess their long-term effects.
4. There is a health dilemma
As often in health-related subjects, it is hard to define with certainty a cause-and-effect relationship between the use of a substance and a body reaction, as many aspects, such as genetics and environmental contexts, are often overlooked.
5. Difficult to identify
Athletes using performance-enhancing drugs might take more than one banned substance, making it difficult to isolate the health effects of each substance.
Anabolic steroids
Anabolic steroids are among the doping substances whose health effects are most well-documented. They are used in sports like sprint competitions or weight lifting because they speed up protein synthesis in muscles, leading to increased muscle mass and strength.
A famous case of steroid use involves tennis player Jannik Sinner, who won Wimbledon this year. The Italian athlete tested positive for steroids in March 2024 and received a three-month ban by WADA.
These products can cause major physical side effects. 'Since the heart is also a muscle and steroids lead to muscle growth, the heart itself could also grow,' Astrid Kristine Bjørnebekk, group leader of the Anabolic Androgenic Steroid Research Group at the Oslo University Hospital, told Euronews Health.
'So it [the heart] increases in size, the ventricular walls get thicker and stiffer, which will affect the heart's ability to pump blood to the rest of the body and over time, this can lead to heart failure'.
Some studies have also suggested that these heart problems may persist in the long term.
Bjørnebekk explained that anabolic steroids disrupt hormone production, and research has also found reduced brain volume in the cerebral cortex among users, though scientists are still working to understand what these changes mean.
Erythropoietin (EPO) and blood doping
Erythropoietin (EPO) is a hormone that stimulates the production of red blood cells, enhancing endurance. It is mostly used in competitions such as cycling or marathon running.
Similarly, blood doping involves removing blood and re-transfusing it after the body has replaced the lost blood cells. This increases the total red blood cell count, improving the athlete's capacity to perform in the short term.
The most well-known athlete to have used these substances is the United States' cyclist Lance Armstrong, who admitted using banned substances in an interview with Oprah Winfrey in 2013.
Overall, both blood doping and EPO are associated with risks of infections and major cardiovascular problems like blood clots, strokes and heart attacks.
However, this verified connection should be approached with caution and analysed on a case-by-case basis. For instance, in the 1990s and 2000s, media and experts suggested that over 15 Belgian and Dutch cyclists had died from heart attacks in the late 1980s due to EPO use. However, later studies found no clear evidence to support this claim, highlighting that the cause-and-effect relationship is more nuanced.
Unlike steroids, research on the long-term effects of EPO and blood doping is somewhat more limited.
Beta Blockers
Probably less known than other performance-enhancing drugs, beta blockers are medications normally used for heart conditions. They are banned in specific sports like archery and shooting because they help athletes perform more calmly by keeping their heart rate low and reducing tension in their bodies.
One of the most famous athletes who tested positive for beta blockers was North Korean shooter Kim Jong-su, who tested positive during the 2008 Beijing Olympics.
Common side effects include fatigue, dizziness, nausea, constipation, and erectile dysfunction.
As far as long-term issues are concerned, some studies have associated chronic use of beta blockers with an increased risk of Parkinson's disease. However, there is little research focused specifically on beta blockers use in sports.