How can a teenage girl get toned?

Your really going to 1st need the use of an idea that will spur on your imagination. You will need to cultivate a pion, a desire that is over whelming. Also surround yourself with examples of exercise and fitness as constant reminders to get in shape. second read all material that you can get your hands on in regards to fitness, hang out with others that exemplify health, mind body type personalities. It appears that what you have said, that you get bored very quickly, this will have to change, you will need to try to focus your mind. This has allot to do with your imagination, try picturing yourself as something amazing in your mind, this is very important. I train people for a living and I find that most people lack this component, it is very essential while exercising, most people want immediate gratification, we are brought up this way in this country of ours. So patience and imagination are key to what you are going to do. now you don't have weights, but however, you do have yourself. The exercises that should be done are calisthenics or core body workouts. Do free squats, walk lunge, push-ups, tricep dips, side laterals with books of equal weight, etc, etc. Second to this is your diet, now all that is really required here is common sense, you see eating the standard three meals a day might not work for you becuase while working out you will be more hungry through out your day. Eat small meals. They should be equal in amounts, Protiens , carbohydrates, minerials, fats, fiber.