Dance and dress. Energize first thing in the a.m. While you're getting dressed for school, crank up the tunes in your room and dance like nobody's watching. (They aren't.)
Burn some calories before the bus. Don't just stand there waiting for the school bus to arrive. Rock, sway, move from side to side, or pace. Any motion burns calories. For a bonus, use your backpack as a weight to do some arm curls.
Walk the lot. Drive to school? Pick a parking spot a little bit farther from the door than you usually would. Each week park farther and farther away. You'll walk more steps, and your car will be less likely to get dings.
Stealth strengthening. Walking through the hallways at school, get in a few minutes of core muscle work on the sly. Pull your belly button in, roll your shoulders back, and breathe in and out deeply. It'll help you look good, too.
Straighten and stretch. At your locker or in the bathroom, s-t-r-e-t-c-h! Lace your hands together with palms facing out. Straighten your arms and hold for 10 seconds. Relax, and then repeat a couple of times.
Talk eye-to-eye. After school, give your thumbs a break. Skip texting with your best friend. Instead talk face-to-face while you go for a walk together. The bonus round? Try going a day text-free.
Do abs during ads. Challenge your sibling or friend to a contest during a TV commercial break. See who can do the most crunches or sit-ups, or who can race upstairs and back the fastest.
Relay chores. Sneak in more steps while doing chores. Head upstairs and get the trash from one room, then back downstairs to take it outside to the garbage can. Then go back upstairs and get the trash from a different room and take it outside. Time yourself and see if you can go faster each week.
Stand up. Stand up while on your phone or watching TV instead of lying down or sitting on the couch or bed. (Yes, it's that simple.) To mix it up, strike a yoga pose or do a stretch or squat every few minutes, or every time your friend or an actor says a certain word.
Play with kids. Don't take the word "babysitting" literally. When you're watching kids, be active. Play tag with them, climb on the playground equipment, and challenge them to a jumping jack contest.
Caloric clean-up. Vacuum, organize your closet, wash the car, or mow the grass. Yeah, they're chores, but they're active ones -- and can burn around 200 calories an hour.
Play to sweat. Go with video games that get you moving, like Just Dance, Rock Band, Shaun White's Skateboarding, Sports Active, or Wii Fit. Or make other games more active by standing while you play.