Model extraordinaire and Project Runway pioneer Heidi Klum reveals her stay-slim secret in May's Good Housekeeping magazine. She doesn't whisper anything about strict diets and hard-core workouts, though. Nope. It's all about her kids.

Klum's three children -- ages four, two, and one -- keep her busy all the time, says this beauty who reports that staying active with her little ones is how she stays in such good shape. I'm not sure that's all it takes -- I'm a mom too and simply moving with my boys just isn't enough -- but apparently it's one piece of the puzzle for this Supermom who says working in the garden, jumping on the trampoline, climbing trees, and feeding ducks in the park top her activity list.

Do your kids keep you in shape?

For more celebrity diet and fitness scoop, check out this AOL Body site.