Endorphins cannot cross the blood-brain barrier, because of their molecular structure. So, even if runners’ blood contains extra endorphins, they will not reach the brain and alter mental states.

Endorphins are tiny neurochemicals that play an important role in your body. Your body releases endorphins naturally in response to pain or stress, but also during other activities like eating ...

That endorphin-fueled rush, that rare wave of euphoria you chase like a pot of gold at the end of your sweat-soaked rainbow? No one is sure whether it really exists. Or precisely what causes it.

Studies have long suggested that exercise triggers the release of “feel-good hormones,” or endorphins, in the brain. New research, however, suggests that this effect is very much dependent on ...