In the middle of Kelly Drive, a Philadelphia Marathon volunteer in an electric blue shirt stands with both arms stretched wide, shouting, “Caffeine! Caffeine!”
The second half of the marathon is a loop in which runners pass her outbound between miles 16 and 17 and returning between miles 22 and 23. On her left and right, racers grab at the packets of Mocha Clif Shot Energy Gel. She holds them loose in her hands so participants can easily snatch those 1.2-ounce packets, each of which contains 50 milligrams (mg) of caffeine.
It isn’t known precisely why two runners died on this course in 2011, one in the full marathon and one in the half marathon.1 The marathoner fell right before reaching the finish line; the half marathoner collapsed after passing beyond the line. This specific form of death has become common enough that it’s now reported in the same format: name, age, where they collapsed, and race experience.
Most studies about why these deaths occur have focused on the heart, and how it changes during strenuous activity. But the packets handed out by that race volunteer could be another factor as to why these deaths are so similar, and why heart attacks claim runners who’d had no prior cardiac problem and who’d previously completed multiple marathons without incident.
“Caffeine! Caffeine!” she calls, and runners in neon shirts and shorts and gloves and compression socks snatch them from her hands.