Actress Jessica Alba arrives at The Huffington Post Pre-Inaugural Ball in Washington, DC January 19, 2009.[Agencies]

Jessica Alba has revealed the secret behind her post-pregnancy figure - she wore a girdle.

The 'Sin City' star - who gave birth to her daughter Honor Marie last June - has admitted her trim body has little to do with hours spent at the gym.

She said: "I wore a girdle. Eight weeks after my girlfriend had her baby, you could see her six-pack. She told me to put an elastic band around my waist - any kind of band or girdle works. I didn't recover as fast as she did. I don't have a six-pack - that's just not my body at all."

Jessica - who married her husband Cash Warren in a secret ceremony last May - hated working out after having Honor Marie, and refuses to return to the gym.

In fact, Jessica claims the easiest part of having her daughter was the labour itself.

She added to Elle magazine: "Contractions aren't that bad. If you've ever had bad cramps? That's what they're like. But that moment when they put the baby on your chest - that's deep. It's a deep experience."

The 27-year-old actress finds it so difficult to be away from her eight-month-old daughter she uses a computer programme to keep in touch.

She said: "This is the first time I've been away from her. It's been six days. It sucks - it's the worst thing ever. But we Skype, so I can see her on video. The worst is when you can see her little chubby hands grab the screen, and I'm not there."