Here's an easy way to strengthen your quads: Lean against a wall, then slide down a little until it feels like you're sitting in a chair. Hold that position for about 15 seconds, breathing in through your nose and out through your mouth.

Think it's easy? Here's the catch- no hands aloud! A lot of kids (and grown-ups too) use their arms to lessen the load. Instead, put your arms at your waist, or even better, imagine you're reading a book or playing a video game. That will keep your hands busy! If you're doing the exercise correctly, you'll feel it in your quads (upper legs).

Afterwards, give each leg a good stretch, like the photo. If you're feeling strong, do the whole thing again!