Taryn Matthews

At mile 18 of the New York City Marathon, Rachel Apa texted her dad one word. "Ow." A mile later she sent him "Ow ow." At mile 23 he texted her "Final stretch." She never wrote back. Rachel was 24 and running her first marathon. She'd been a starter on Bucknell's Division I field hockey team, and these days she was working as a product manager while starting her MBA. She ran Sunday for the Parkinson's Foundation because her grandfather died of the disease in 2022, and she said he was the one who taught her to push her limits. She went down in Central Park around mile 24, two miles from the finish. Spectators started CPR and race medics used a defibrillator on her before the ambulance got there. Doctors at Mount Sinai worked on her for about six hours. Her dad says the cause was rhabdomyolysis. Rhabdo is when your muscle fibers break down so badly they spill what's inside them into your bloodstream. You usually hear about it as a kidney problem, because one of the things that spills out, a protein called myoglobin, can clog up the kidneys over a few days. It also has a much faster way to hurt you, and it comes down to potassium. Almost all of your potassium is stored inside your cells, and the biggest stockpile is in your muscles. Inside a muscle cell it runs around 150 millimoles per liter. In your blood your body keeps it somewhere between 3.5 and 5. So your muscles are sitting on roughly 35 times more potassium than your blood, and your heart only stays on rhythm because your body holds that blood number in a really tight window. When a lot of muscle breaks open at once, all that potassium has nowhere to go but your blood. Once it gets past about 6.5, doctors treat it as an emergency, because the electrical signal that times every heartbeat can start to misfire. Now think about what every marathoner's legs go through. Researchers have been testing runners' blood for the enzyme that leaks out of damaged muscle going back to the 1979 Boston Marathon, and it shows up elevated after the race. In that Boston study, the faster runners actually had more muscle damage than the slower ones. Which means pretty much everybody out there Sunday was hurting by mile 18. More than 61,000 people finished, and almost all of them could have texted "Ow" at some point along the way. From the inside, legs that are just wrecked and muscle that's breaking down can feel a lot alike, and Rachel had spent years as a college athlete learning to keep going when it hurt. Doctors from Mount Sinai and Lenox Hill published a paper on this exact race back in April. They counted 24 runners treated for rhabdo after the 2022 NYC Marathon, which got up to 75 degrees, and 15 total across five other years. None of them died. What happened Sunday is about as rare as it gets. Her fundraising goal for the Parkinson's Foundation was $4,000. Since Sunday, people who never met her have pushed it past $22,000.