Britney Spears shows off her ab-fab bikini body during Hawaiian getaway

Spears tweeted a bikini photo (twitter.com/britneyspears)When Britney Spears was fresh on the pop music scene, and practically lived in midriff-exposing outfits, she shared her secret for amazing abs: Her daily exercise regimen included 1,000 — yes, 1,000 — crunches a day. Well, it looks like the mother of two is still doing them!

In Hawaii for a getaway with fiancé Jason Trawick, 40, and her two sons, Spears tweeted the above ab-fab photo of herself in a blue and purple string bikini. "Getting ready for some pool time," the 30-year-old entertainer wrote in the caption along with the picture, which was taken in what appears to be the living room of her hotel suite. "Having a blast."

Although she has her hands full with "X Factor" and her two sons — Preston, 6, and Jayden, 5, who were also in the photo — Spears is clearly making time for exercise because her stomach looked toned and tight.

After traveling across America for "The X Factor" auditions — including San Francisco, Austin, and Providence — Spears hopped a flight to Maui earlier this week for some rest and relaxation. On Wednesday, she posted another photo to Twitter showing her with Trawick and the boys. They were all wearing leis — and big smiles. "Happy 4th of July from the Aloha State!" she wrote.