Summarize this article in one sentence.
Physical activity is important not only for losing weight, but also for keeping your bones, muscles, heart, and lungs strong. Try to do 60 minutes of moderate physical activity each day, such as jogging, walking, dancing, swimming, playing tennis, or biking.  If you’re not used to exercising, start with shorter times and less intense exercise. For example, you might start by walking for 10 minutes each day, then gradually build up to a daily 20-minute fast walk or jog. Depending on your current weight or your fitness goals, you may need to spend more time exercising or do more intense exercise. Talk to your doctor or a PE instructor to find out how much you need to exercise. In addition to aerobic activities that get your heart pumping, like running and biking, you should also do exercises that help you build muscle. At least 3 days a week, add some strengthening exercises to your regular 60 minutes of physical activity.  Some good strength-building exercises include doing planks or squats, climbing, and using resistance bands. You can also ask a fitness instructor for advice on how to safely lift weights. Building muscle helps you burn fat more efficiently, and also makes you less prone to injury. In addition to working out, you can also look for little ways to get more physical activity during your daily routines. For example, take the stairs instead of an elevator or escalator whenever you can. Every little bit can make a difference!  Doing work around your house and yard can also help you burn calories. Kill 2 birds with 1 stone by cleaning up your room or volunteering to mow the lawn. If you’re in school, try walking or biking there if possible. Even standing instead of sitting while you work at a desk can help you burn extra calories! When you have a world of entertainment and information literally at your fingertips, it’s easy to forget to get up and move. Make a decision to limit your time on the phone, at your computer or tablet, or in front of the TV.  Try setting specific limits for yourself. For example, you might commit to spending no more than 1 hour watching TV per day. If you find yourself too tempted to play on your phone, try installing an app like BreakFree or Moment that will remind you to take breaks or lock you out during designated phone-free times. If you have to sit a lot while you study or work, try to take occasional breaks to get up and walk around or stretch.

Summary:
Get at least 60 minutes of moderate exercise daily. Incorporate strength training into your exercise regimen. Find ways to be more physically active throughout the day. Minimize screen time and other sedentary activities.