Rachel Apa, a 24-year-old former Division I field hockey player, died after collapsing near Mile 24 of the New York City Marathon on November 1, 2026. A seemingly healthy Pennsylvania resident, Apa was participating in her first-ever marathon when she collapsed in Central Park. She was transported by ambulance to Mount Sinai Medical Center, where doctors attempted to save her life for more than six hours before she died later that day. Her father, Steve Apa, stated her death was linked to rhabdomyolysis, a rare but dangerous condition in which damaged muscle tissue breaks down and releases harmful substances into the bloodstream. While the city’s medical examiner is still investigating the official cause of death, a spokesperson stated on Tuesday evening that the investigation remains ongoing and no official determination has been made.
Muscle Cell Breakdown Releases Toxins into the Bloodstream
Rhabdomyolysis occurs when skeletal muscle cells break down and release their contents—including the protein myoglobin and electrolytes like potassium and phosphate—into the bloodstream. In large quantities, these substances can be toxic to the body, straining the cardiovascular system and potentially causing acute kidney failure. Dr. Douglas Farrell, a nephrologist at Mount Sinai Hospital, explains that the process involves muscle cells dying and releasing contents that are quite toxic to the body and to the kidney.
The condition is notoriously difficult to predict. According to Dr. Marie Vangstad of Oslo University Hospital, the most significant risk factor is unusually strenuous or unaccustomed exercise,
particularly a sudden increase in training volume or intensity. Even well-conditioned athletes can develop the condition, which manifests through symptoms such as muscle pain, weakness, tenderness, swelling, and dark, tea-colored urine. Other warning signs include nausea and decreased urination.
Heat and Humidity Trigger Muscle Damage During Races
Experts point to temperature as a primary risk, noting that the body requires time—often one to two weeks—to acclimate to hotter or more humid conditions. When the body cannot shed heat quickly enough, it may be unable to avoid the muscle damage that leads to the condition.
In 2022, a study found 24 runners were treated for rhabdomyolysis at nearby hospitals, a sharp increase compared to the 15 cases reported over the previous five years combined. Researchers suspect that record-high heat and humidity during that specific race contributed to the spike. While roughly 26,000 cases are reported annually in the United States, medical professionals emphasize that deaths from exercise-induced rhabdomyolysis remain exceedingly rare.
Medical Treatment Focuses on Fluids and Kidney Protection
Because symptoms like muscle soreness are common in endurance events, the condition can be difficult to identify in the moment. When recognized, treatment centers on the administration of fluids to protect kidney function, monitoring electrolytes, and, in severe cases, the use of dialysis. If heatstroke accompanies the condition, doctors may use ice baths to rapidly cool the body. The complications can be severe; high potassium levels can disrupt the heart’s electrical activity, potentially leading to cardiac arrest. Dr. Bradley Uren, an emergency medicine physician at University of Michigan Health, noted that in the case of the Pennsylvania runner, it appeared that the worst case scenario happened just very, very quickly.
