Britney's Bikini Body Through the Years

 Sept. 16, 2001

A well-toned Spears showed off her iconic abs in a teeny-weeny two-piece in Sydney, Australia. "I probably do like 500-sit-ups," Spears has told Oprah Winfrey. "And If I'm having a really good day, I'll do like probably, 1,000."

April 23, 2004

On a beach in L.A. during a break in touring, the-Cheetos-and-Red-Bull loving singer (with a cigarette in hand) set off a media frenzy when she was photographed cavorting with Kevin Federline.

July 15, 2004

"Lounging around" as a newlywed caused Spears to put on pounds, she has said (here at a hotel pool in Marina del Rey, CA).

April 13, 2005

Bun in the oven! The parents-to-be strolled along the beach hand-in-hand in Destin, Florida, the day she announced she was pregnant with their first child.  While carrying Sean, Spears gave in to her cravings at Wendy's and Chili's.

June 15, 2006

Hours before her infamous interview with Matt Lauer aired, Spears (pregnant with #2) soaked up rays in Miami. When asked about her marriage, Spears denied any problems. "[Kevin] helps me," Spears told Lauer. "He has to. I'm an emotional wreck right now." On November 7, Spears filed for divorce.

Nov. 7, 2006

A six-months pregnant Spears walked along the beach in L.A. while picking out shells for Sean Preston on the day she filed for divorce from Kevin Federline. "I love my child and I would do anything to protect him," the singer has said.

Feb. 28, 2007

Before checking into Promises rehab center in Malibu for the second time, a  newly bald Spears (in a blonde wig) headed to the Mondrian hotel where she made two new gal pals at the poolside Star Bar.

July 18, 2007

Spears and her then assistant Shannon Funk stripped down to their skivvies and took a dip in the ocean in Malibu. "I used to walk around my house completely naked. And my dad would say, 'Britney, put some clothes on, we have people over,'" Spears told Esquire.

April 23, 2008

To get back in shape, Spears (in Malibu) has been hitting Bally Total Fitness in L.A. "She takes her workout seriously," says a gymgoer.

May 18, 2008

A happy and healthy looking Spears hit the beach for a five-day vacation with Mel Gibson and her dad in Costa Rica. While surfing, a witness says, Spears yelled, "I'm scared!" before hitting the water for 40 minutes. "She caught some waves."

Aug. 8, 2009

"I've had to work hard at getting [my body] back to where it used to be," Spears (at a photo shoot for the 2009

Aug. 21, 2009

The singer showed off her bikini bod with sis Jamie-Lynn, 18, during an outing with sons, Sean, 4, and Jayden, 3, in Miami. "They both looked to be in pretty good shape," a witness to the family's outing at the Mandarin Oriental Hotel tells Us.

Oct. 18, 2009

On a break from her Circus concert tour, Spears donned a black bikini and shades for a three-night getaway at the Tides Zihuatanejo resort in Mexico with agent beau, Jason Trawick, and her sons.

Nov. 15, 2009

The singer, who wrapped her tour last month, shed a reported 20 pounds before hitting the road, thanks to two-hour cardio-and-strength training workouts three times a week (on top of dance rehearsals).
Source: USmag