02/04/2009 at 06:55 PM EST
wants the world to know her body after baby secret – and it has nothing to do with celery sticks or crunches at the gym.
"I wore a girdle," the actress, 28, tells the March issue of Elle
. "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."
Adds Alba, "I didn't recover as fast as she did. I don't have a six-pack – that's just not my body at all."
The actress confesses that she tried working out to get in shape for a calendar shoot
, but quickly gave it up.
"[The workouts] were horrible," she tells the magazine. "I cried. And I haven't worked out since."
What wasn't so tough for the Fantastic Four
star? Surprisingly, childbirth itself.
"Contractions aren't that bad," she says. "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."
Actually, tears have been a somewhat common occurrence for the new mother
, especially when she is away from daughter, Honor.
"This is the first time I've been away from her," Alba tells Elle
. "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."
The magazine reported that the actress began welling up at the memory.
"That's a new thing – I never cried before," she says. "Just being a mother is making me a big, weepy mess."
Get the dish on how Jessica shed the baby weight
Read more about how celebs bounced back post-baby!