marathon runners, the reward for pushing themselves during the
race extends beyond the finish line in the form of a hidden
perk: runnerís high.
knowing what causes that euphoric feeling ó and how to
achieve it ó has been a bit of a mystery.
identified in the 1980s, runnerís high has long been
attributed to the bodyís release of endorphins, the
feel-good hormones. But a flurry of research in recent years
suggests that the source of that floaty sensation many runners
experience might be more complex than previously believed.
from the University of Heidelberg led a groundbreaking study
published last year that tested mice before and after spins on
a running wheel. Not surprisingly, the mice were less anxious
and less sensitive to pain after their runs.
the scientists suppressed the part of the brain that contains
"endocannabinoids" ó chemicals that have the same
relaxing effect on the brain as marijuana ó and tested the
mice again before and after exercising, they found no change
in the anxiety and pain levels. Thus, they concluded, the
endocannabinoids were behind the runnerís high.
other research points to yet another source: a hormone called
leptin that is linked to hunger feelings.
theory involving leptin says that when we have lower levels of
leptin, we are more likely to run farther like our ancestors
had to in order to find food. On longer runs, some researchers
believe, our bodies are more likely to achieve a runnerís