"Use it or lose it" is so true when it comes to exercising our bodies. Exercise has been shown to increase the quality as well as the quantity (number of years) to one's life. Without it our minds become dull, likely develop dementia, we contract diseases, reduce our productivity, and we become more moody.
One of the best antitodes for moderate depression is getting exercise, especially outdoors in the day-time. Breaking a sweat often results in improvements in the ability to think, learn, focus, feel better, and to improve other areas such as work productivity and relationships.
Bones are made stronger through exercise, especially higher impact forms (such as walking, running and racquet sports).
Avoid jumping into the car. Walk or cycle whenever possible. Make yourself visible! Take transit. Yes, it usually takes longer using any of these modalities, but your body and your mind will thank and reward you!