From field hockey and basketball to soccer during the school year, to powder-puff football and swim team in the summer, Anna, a 16-year-old student from Vienna, VA, is always on the go. Most of the time, she doesn't even think about the fact that she's exercising when she plays sports.

"I'm so busy having fun that I forget I'm staying fit!" she says.

However, if you're like most Americans, you're already out of breath just thinking about Anna's busy schedule. According to the surgeon general, at least 60 percent of the people in the U.S. don't get enough exercise and are out of shape. The average American teenager watches three-to-four hours of television a day — and with all that good stuff on the tube, who wouldn't want to lay around on the couch and watch all day!

During the time it takes to watch your favorite show, you could be getting in shape. Read on to learn what you can do to get in shape in just 30–60 minutes a day!

Why Exercise?

Just a few incentives before we start. Exercise is really good for you! Exercise can

  • keep your weight under control
  • make your bones and muscles strong
  • help you manage stress and
  • improve your sleep at night

The reverse is also true — not exercising is really bad news. If you don't use it, you lose it. Your muscles begin to atrophy, and your bones begin to thin after just three days of inactivity.

But it's never too late to get back on track. When you start exercising again after a period of inactivity (like that South Park marathon last weekend), your body works hard to make up for lost time. All the activities that made you out of breath just a few weeks before should be a breeze with consistent exercise.

The Notorious F.I.T.
So, what are you waiting for? Turn off the tube and get active. You don't have to be a year-round athlete like Anna to get in shape. All you have to remember about being fit are three letters: "F," "I," and "T."

"F" stands for Frequency — how often you exercise. Work out at least three-to-four times a week. You'll get the most benefits if you spread it out over the week, instead of trying to do it several days in a row.

"I" stands for Intensity — how hard you work out. Get your heart rate up to about 50 percent higher than normal. Don't feel like counting beats? Go by this general rule: you should be able to talk while exercising, but you shouldn't be able to sing.

"T" stands for Time — how long you work out. Aim to keep your heart rate up for 30-to-60 minutes, or as long as a sitcom or two.

Try these tips to get going and keep going:

  • Choose an activity that you like to do. Although Anna is into team sports, they're not the only way to stay fit — going out dancing, walking the family pooch, and taking your bike out for a spin all count as exercise.
  • Start slowly if you're out of shape, and don't overdo it.
  • Stay hydrated by drinking water before, during, and after your workout.
  • Listen to music or exercise with friends to keep your workout fun.

And remember, in the time it takes to watch one TV show a few times a week, you could be getting in super shape.