How can training for a sport affect your mental health?

Feel better many way: Primarily it will give you a focal point around which you will build / schedule your daily routine. This helps with good planning, better health choices (eating, especially), and adds structure to your life. The sheer physical activity promotes positive chemical changes in your body (including your brain), as well as muscle,joint,system, activity. All combined, you lessen your anxiety and stress.

Fight-or-flight: Exercise can improve your mood, stamina and personal life. The experts say that in sports, 90% of performance is mental.