Fitness competitor Joanna Wietrzyk won the Hyrox elite race in Beijing on 12 September, but her victory was overshadowed by a medical emergency that unfolded during competition. The Australian athlete experienced severe gastrointestinal distress mid-race, resulting in visible faecal matter running down her legs as she continued to compete on shared equipment. Despite the incident, Wietrzyk finished in 1 hour 1 minute 23 seconds, securing first place by 45 seconds ahead of runner-up Alyssa McElheny and earning 105 Elite 15 ranking points.
The incident prompted significant scrutiny of event management and hygiene protocols. Hyrox co-founder Moritz Fuerste issued a public apology, stating that organisers should have withdrawn the athlete from competition. The venue's course areas were subsequently disinfected following the race. The controversy centred on concerns that Wietrzyk was permitted to continue despite visible signs of severe illness and the associated health and hygiene risks.
Wietrzyk's experience, while dramatic, reflects a widespread phenomenon in endurance athletics. Runner's diarrhoea—or runner's trots—has affected competitors for decades, from ancient Olympic athletes to modern marathon winners. The condition is far more prevalent than public awareness suggests, with approximately 60% of endurance athletes reporting some form of gastrointestinal symptoms during training or competition, according to research cited by Kayla Henningsen, a PhD candidate studying exercise gastroenterology and extreme physiology at Monash University. The American Medical Society for Sports Medicine acknowledges this as a recognised medical concern in athletic populations.
What causes bowel emergencies during intense exercise?
The mechanisms underlying exercise-induced gastrointestinal distress remain incompletely understood, despite being documented in scientific literature for over a century. Research suggests multiple interconnected factors contribute to the condition rather than a single straightforward cause.
During intense exercise, the body redirects blood flow away from the digestive system toward skeletal muscles, which reduces the motility and absorptive capacity of the intestinal tract. This physiological response becomes particularly problematic when athletes consume large quantities of sports drinks, energy gels and nutrition bars during competition. The lower intestines struggle to absorb these nutrients efficiently when blood supply is compromised.
Environmental conditions amplify the problem. Heat exposure worsens gastrointestinal symptoms because the body diverts additional blood to the skin for cooling and to maintain core temperature—further reducing digestive function. According to Prof John Hawley from Australian Catholic University, weight-bearing exercise lasting 90 minutes or longer, particularly running, produces more severe symptoms than other endurance activities.
This is because of the vertical up-and-down impact, and why cyclists can tolerate a lot more food and drink.
Kayla Henningsen describes this mechanical effect as
mechanical jostling of the intestines, and identifies dehydration and food intolerances as additional contributing factors. Emerging research from Monash University explores the role of the gut-brain axis, suggesting that performance-related stress may be directed toward the gastrointestinal system through hormonal stress responses and alterations to the microbiome, alongside changes in intestinal pH.
How common are these incidents among elite athletes?
Public incidents of bowel emergencies during major races have occurred regularly over the past three decades, though many go unreported. In the 1998 London Marathon, winner Catherina McKeirnan experienced multiple episodes of diarrhoea during the race. Paula Radcliffe, who won the 2005 London Marathon, was photographed relieving herself by the roadside near the finish line, later attributing the episode to consuming too much gluten-free pasta and grilled salmon the previous evening.
More recent cases include American athlete Taylor Knibb, who won the Dubai T100 triathlon in 2024 despite experiencing bowel loss during competition, publicly stating:
I just shit myself … so can you not get my ass? Thank you.TikTok personality Davis Clarke chose not to stop for a toilet break during the 2024 Boston Marathon, resulting in a similar incident. French race walker Yohann Diniz, a world record holder, suffered visible gastrointestinal distress during a 50km walk at the 2016 Olympics, with blood and faecal matter visible on his legs, yet still finished in eighth place.
Although women report runner's trots more frequently than men, male athletes are not immune. One of the most widely publicised cases involved Swedish runner Mikael Ekvall, who completed a half-marathon in 2008 while experiencing severe diarrhoea for 10 kilometres, earning the viral nickname
bajsmannen(poop man) and finishing in 21st place despite the ordeal.
Why has this condition been overlooked for so long?
Despite extensive documentation in sports medicine literature and frequent cases observed by sports professionals, scientific understanding of exercise-induced gastrointestinal distress only began developing in the 1980s and 1990s. The condition likely affected competitive athletes since ancient Olympic times, yet remained poorly understood due to its multifactorial nature and the difficulty of isolating a single causative mechanism.
Can athletes prevent these emergencies?
Complete prevention may not be possible, but risk reduction strategies exist. Henningsen emphasises that gastrointestinal distress during extreme events does not necessarily indicate poor preparation or inadequate fitness. Instead, she recommends a personalised approach to prevention, as triggers vary significantly between individuals.
Key prevention strategies include avoiding unfamiliar foods before competition, maintaining adequate hydration, managing heat exposure and gradually training the digestive system to tolerate carbohydrates and fluids during exercise. Prof Hawley stresses that
the gut is an 'athletic organ' and can be trained to tolerate nutrient loading – that is, eating and drinking during exercise – so practise in training what you will be doing in a competition.
Henningsen recommends treating gastrointestinal function as a trainable performance system, advising athletes to maintain detailed records of foods, fluids, symptoms and environmental conditions to identify individual patterns and triggers. Research from Monash University suggests that consuming carbohydrates during prolonged exercise may provide protective benefits. Emerging evidence also indicates that proteins, particularly glutamine, may support intestinal integrity, and some athletes report improvements with low-fibre and gluten-free diets, though the scientific evidence for these interventions remains inconclusive.
Most gastrointestinal symptoms experienced during exercise are mild and temporary, with no long-term health consequences. However, Henningsen offers an important caution:
If symptoms are frequent, severe or worsening, see a healthcare professional. Persistent gastrointestinal issues should not simply be accepted as 'part of the sport'.
What happens next for Hyrox and event safety?
Following the Beijing incident, Hyrox announced revised competition protocols designed to prevent similar situations in future events. The new guidelines are expected to be implemented at upcoming competitions, including the Hamburg Major, which represents the first major ranking target of the season for elite athletes competing for Elite 15 status. Wietrzyk and other competitors will face the updated safety and withdrawal procedures at future Hyrox events worldwide.
