Beyonce Knowles has revealed that she buys clothes which are too small for her as a motivation to shed extra pounds.

In an interview to Self magazine, the singer and actress, known for her curvy figure, admitted that it takes a lot of hard work for her to stay in shape so she sets goals for herself.

"I buy something too small and then say, "I have a reason." I need to wear these jeans or this hot dress," Us magazine quoted her as saying.

The 27-year-old beauty also revealed that her dream of winning an Oscar also drives her to work out rigorously.

To say motivated, Knowles keeps a painting of an Oscar at the gym -- so when she's on the treadmill, she's running toward her goal.

She added: "I look at it, and I'm like, "Okay, I have to stay in shape.""

Photograph: Cover of Sports Illustrated magazine