Summarize this article in one sentence.
Throughout your day, walk rather than ride or drive when you can. If you drive somewhere, park at the far end of the parking lot and walk to the building to get some extra steps in. For example, you could walk around the building when you're waiting for an appointment, rather than sitting in a waiting room flipping through a two-year-old magazine. Typically if you tell the receptionist you're going for a walk, they'll let you know about how long it will be. Getting at least 7 or 8 hours of sleep each night can help lower your stress levels and improve the functioning of your immune system. You'll also likely find that your productivity during the day will improve, since you'll think more clearly and find it easier to concentrate. While you sleep, your brain releases chemicals that affect your heart rate, blood pressure, metabolism, and digestion. Alcohol and caffeine can wreak havoc on any diet and exercise plan. They are also diuretics that can cause dehydration and other physical problems, particularly if you consume significant quantities on a regular basis.  If you exercise regularly, eat well, and get plenty of sleep, you'll likely find that you don't need as much caffeine to get through the day. Sleep gives your body a chance to renew all systems and repair any damage done throughout the day. Too much screen time negatively affects both your physical and mental health. Try to go one day a week without turning on electronic devices or watching television. If you can't do it for a whole day, at least try to give yourself a few hours to unplug. You might also set aside 30 minutes to an hour each day to unplug. Put on some soft music and read a book or meditate.

Summary:
Find opportunities to walk. Get a good night's rest. Limit alcohol and caffeine. Unplug from time to time.