Nathan loves running long distances and often describes his runner's high. the phenomenon of runner's high is associated with the body's production of

The correct answer is endorphins.

During strenuous exercise, the brain releases the neurotransmitter called endorphins. Endorphins are known as "feel good" chemicals that produce a feeling of euphoria, reduce anxiety and the ability to experience pain. Endorphins also produce a feeling of happiness and relaxation after an intense exercise session. 

General during the American Revolutionary . But then became a traitor.