How does increasing activities help relieve stress?

Many ways....: First, you must enjoy your physical activity. It becomes habit forming. Gives yourself pride, better health, and appearance. But the stress relieving issues are often ignored. Exercise done regularly lowers circulating stressor hormones in the body, most specifically catecholamines (adrenalin/noradrenalin), and cortisol. Lowering these levels decreases the feeling of anxiety. You also sleep well.