Heidi Klum gave birth to daughter Lou five weeks ago -- and she's back in action!

The mother of four tells "Extra" she hasn't been working hard to get her body back in runway model shape. She revealed, "I don't do too much, I have to tell you."

Check out adorable photos of Heidi through the years

Klum added, "I do eat very healthy and I drink lots of water and I breastfeed and I'm just very active."

See Heidi and Seal's most romantic moments