RUNNERS HIGH- ECB, DA

Scientists used to chalk these feelings up to an increased concentration of endorphins, but we now know that the runner’s high comes from the so-called endocannabinoids, or eCBs (named for their molecular resemblance to the active ingredient of cannabis). These are powerful painkillers, released during long-distance running, that also stimulate the secretion of the neurotransmitter dopamine from various neuron populations in the brain. Dopamine is often popularly seen as the brain’s pleasure-inducing reward chemical, and while there is more to it than that, many recreational drugs—including cannabis, of course, but also nicotine, heroin and cocaine—do indeed stimulate the release of dopamine, inhibit its absorption or mimic its actions.