psych benefits of exercise

We often hear about the physical benefits of exercise (e.g., increasing heart health), less often are the psychological benefits promoted. Yet, engaging in a moderate amount of physical activity will result in improved mood and emotional states. Exercise can promote psychological well-being as well as improve quality of life.
 
The following are common psychological benefits gained through exercise. 
 

As people experience these psychological benefits, it is likely that they also will be motivated to continue exercises so that they continue to receive these benefits.
 
How much exercise is needed to produce those effects?