https://apnews.com/a7285351d1604f219b192997a4ccee50

DOHA, Qatar (AP) — The stopwatch is only one way to measure the gains athletes are making at the world championships this year.

About 200 runners volunteered to swallow red-and-white capsules that contain data transmitters. It's part of an IAAF research project on the effects of heat and body-core temperatures. They couldn't have picked a better time or place — in Doha, where the temperatures reach 100 degrees (38 Celsius) every day, and less than a year removed from the Olympics in Tokyo, where conditions are expected to be every bit as stifling.