Can Exercise Moderate Anger?

Not sure yet but exercise does stops anger inflation (and "helps" neural plasticity on the positive side):
The question of just how, physiologically, exercise blunts anger remains open. Mr. Thom and his colleagues did not test levels of stress hormones or brain chemicals in the test subjects. But earlier work by other scientists suggests that serotonin, a neurotransmitter in the brain, probably played a role, Mr. Thom said. “Animal studies have found that low levels of serotonin are associated with aggression, which is our best analogue of anger in animals,” he said. “Exercise increases serotonin levels in the rat brain.” Low serotonin levels in humans are also thought to contribute to mood disorders.

Changes in the activity of certain genes within the brain may also have an impact. In a 2007 experiment at Yale University, researchers found that prolonged running altered the expression of almost three dozen genes associated with mood in the brains of laboratory mice. Mr. Thom says he hopes that future studies by himself and others will help to determine the specific underlying mechanisms that link exercise and a reduction of anger.