Rachel Apa, a 24-year-old woman from Pennsylvania, collapsed near the finish line of the New York City Marathon on November 1 and died later that day. Her father told The New York Times that her death was linked to rhabdomyolysis, a condition where damaged muscle tissue releases substances into the bloodstream that can harm the kidneys and sometimes the heart. The city’s medical examiner is still investigating the exact cause of her death.
Rhabdomyolysis occurs when muscle cells break down and die, releasing contents that can be toxic to the body and kidneys, according to Dr. Douglas Farrell, a nephrologist at Mount Sinai Hospital in New York City. Various triggers can cause this, including injuries and drug side effects, and symptoms can include muscle pain and dark urine. Dehydration can exacerbate the condition.
When exercise is the cause, it's termed exercise-induced rhabdomyolysis. Farrell noted that his hospital sees a notable number of cases after the marathon. In April, he and his colleagues published a paper observing a significant increase in cases, with 24 runners treated for rhabdomyolysis after the 2022 New York City Marathon, compared to only 15 cases in the five years prior.
Several risk factors can increase the likelihood of developing rhabdomyolysis. Temperature plays a significant role; extreme heat and humidity can prevent the body from cooling down efficiently during exercise, potentially leading to muscle damage. Sudden shifts in temperature can also be problematic. While the body can adapt to gradual temperature changes over one to two weeks, rapid increases are more challenging. Farrell and his colleagues suspect this contributed to the higher number of cases in 2022, which was the hottest and most humid year since the marathon moved to November in 1986. It was also the only year among those studied where the marathon day was significantly hotter than the preceding two weeks.
However, most marathon runners do not develop this condition, regardless of the temperature. Dr. Marie Vangstad of Oslo University Hospital in Norway, who studies rhabdomyolysis, states that it is difficult to predict who will develop the condition. The most significant risk factor is unusually strenuous or unaccustomed exercise, particularly a sudden increase in training intensity or volume. Even well-trained athletes can develop rhabdomyolysis under extreme exertion, and some individuals may have underlying genetic predispositions, though many cases occur in people without any known susceptibility.
Deaths from exercise-induced rhabdomyolysis are exceedingly rare, according to both Vangstad and Farrell. None of the patients in Farrell's paper on the 2022 marathon cases died. Treatment typically involves administering fluids and monitoring kidney function and electrolytes. When heatstroke accompanies rhabdomyolysis, rapid body cooling methods like ice baths are employed. In severe cases, dialysis may be necessary to manage kidney failure.
Diagnosis relies on symptoms, the circumstances surrounding their onset, and blood tests that detect markers of muscle breakdown. However, elevated blood markers alone do not confirm the cause of death, as they can be present for other reasons during strenuous exercise. Recent studies involving over 300 exercise-induced rhabdomyolysis cases found no deaths, and Vangstad emphasized that exercise-induced rhabdomyolysis generally has a very good prognosis with rare serious complications.