Wash some windows for 20 minutes. Clean up the house or apartment with a window-washing session where you're bending, stooping, climbing and stretching to get the job done. You'll burn off 100 calories and enjoy a brighter view!

Swimming, 15 minutes. Get wet and enjoy a few laps. We're not talking Olympic-style relays. Just a few leisurely strokes up and down the pool will get you to that 100-calorie goal.

When you cobble together a few of these activities -- which may be on your daily agenda anyway! -- you'll find that you've put together an effective workout in no time, without setting foot in the gym!