A new study led by the NYU Grossman School of Medicine has found that running increases the levels of a chemical involved in brain cell growth – the so-called “brain-derived neurotrophic factor” (BDNF) - that triggers the release of dopamine, a hormone which plays a crucial role in motivation, movement, and learning.  Scientists have long known that regular running raises dopamine activity in the brain, and could protect nerve cells from damage. Moreover, previous research has found correlations between exercise-driven boosts of BDNF and dopamine levels and...