Actress Katherine Heigl, known for her roles in movies like "Knocked Up" and "27 Dresses", says she stopped pushing the envelope to take on tougher film roles beyond a point.

The 35-year-old took up roles in romantic comedies after failing to push herself to take on a variety of roles.

"I had an amazing time (doing rom-coms). I love romantic comedies. But maybe I hit it a little too hard. I couldn't say no. I stopped challenging myself. It became a bit by rote and, as a creative person, that can wear you down," Heigl told the August issue of Marie Claire, reports contactmusic.com.

Heigl is slated to return to television in November with "State Of Affairs".