#Runner's research shows a #anxiolytic (#anti_anxiety) effect in the #ventral_hippocampus and stimulation of the production of #GABA. In other words, running has a calming effect on anxiety.

Runner's brains produce the stimulation of new neurons that release GABA (gamma-Aminobutyric acid) which acts as a neural inhibitory activity. This produces a calming sense in the brain. This research suggests that the hippocampus of runners produces a different response to stress. For runners physical exertion stimulates neurogenesis (new cell production) in the dentate gyrus, an area in the hippocampus region known for high rates of neurogenesis and receiving excitatory input from the frontal cortex. It also increases production of GABA (gamma-Aminobutryic acid), which calms the nervous system. 

The results support the anti-anxiety effects of long-term running and increased neurogenesis throughout the dentate gyrus (Schoenfeld, T., Rada, P., Pieruzzini, P., Hsueh, B., & Gould, E., 2013).(Schoenfeld, T., Rada, P., Pieruzzini, P., Hsueh, B., & Gould, E., 2013). Journal of Neuroscience, 2013 May 1;33(18):7770-7. doi: 10.1523/JNEUROSCI.5352-12.2013.Physical exercise prevents stress-induced activation of granule neurons and enhances local inhibitory mechanisms in the dentate gyrus.http://www.jneurosci.org/content/33/18/7770.short