A Marathon Runner’s Death Raises Questions About a Serious Muscle Condition

Rachel Apa, 24, died after collapsing near mile 24 of the New York City Marathon on November 1. She was running her first marathon to raise money for Parkinson’s disease research in honor of her grandfather. Her father told NBC News that doctors identified a condition called rhabdomyolysis, sometimes shortened to “rhabdo.” NBC News report

The medical examiner has not yet confirmed her cause of death. Cause of death update from CBS News

But the reports raise an important science question: How can damage to muscles threaten other parts of the body?

When muscle cells spill their contents

Rhabdo happens when muscle cells become badly damaged and release their contents into the blood. Intense physical effort can trigger it, but so can heat, crushing injuries and other causes. The danger can extend far beyond the injured muscles. CDC explanation of rhabdomyolysis

One substance released is myoglobin, a protein that helps muscles store oxygen. Inside muscle cells, it serves a useful purpose. When large amounts escape into the blood, however, myoglobin can harm the kidneys. These organs filter blood and remove waste to make urine.

Damaged muscles also release potassium. This mineral helps nerves and muscles work, including the heart. Too much potassium in the blood can disrupt the heart’s rhythm. That helps explain why severe muscle damage can become a whole-body emergency. Scientific review of rhabdomyolysis

What research shows about the risks

Not everyone with exercise-related rhabdo develops kidney damage.

In a study published in JAMA Network Open in 2024, researchers reviewed records from 200 adults hospitalized with exercise-related rhabdo. Seventeen—about nine in every 100—developed a sudden kidney injury. Nobody in the study died. Read the 2024 study in JAMA Network Open

Kidney injury was more common among patients who were dehydrated or had taken certain anti-inflammatory pain medicines, such as ibuprofen, before hospitalization. The study found a link; it could not prove that either factor caused the injuries.

The researchers also found something surprising. Higher levels of creatine kinase, or CK, did not reliably identify who developed kidney injury. CK is an enzyme that leaks into the blood when muscles are damaged. Doctors use it to help detect rhabdo, but that number alone did not reveal the danger to the kidneys. Read the 2024 study in JAMA Network Open

These findings describe a group of hospitalized adults. They cannot explain what happened to Apa.

Warning signs can appear later

Rhabdo symptoms can include muscle pain much worse than expected, unusual weakness, and urine the color of tea or cola. Symptoms may begin hours or even days after muscle damage.

A person does not need to have every warning sign. Symptoms alone also cannot confirm rhabdo, because other conditions can look similar. Doctors use blood tests to help tell the difference. Anyone with these warning signs should seek medical care right away; young people should tell a trusted adult immediately. CDC warning signs and testing

Why this matters: Recognizing rhabdo early gives doctors a chance to treat it before serious complications develop. Hospital treatment may include fluids delivered through a vein, along with checks of kidney function, potassium levels and heart rhythm. CDC treatment information

What scientists still don’t know

Researchers still need better ways to predict which patients will develop serious complications. The 2024 study looked backward at medical records and included only hospitalized adults in one health system. Its results cannot establish the risk for every athlete—or for children. Read the 2024 study in JAMA Network Open

For Apa’s case, the unanswered question remains separate: an official cause of death has not yet been announced.