Most Improved Celebrity Beach Bodies

julianne hough

By Stacie Anthony and Molly McGonigle

Any season is prime season for scrutinizing celebrity bikini bodies, but summer is by far the best. So let's get started! Click through to see how celebs like Julianne Hough and Jessica Alba are inspiring us with their vastly improved beach bodies.

All that dancing clearly does a body good. While we don't actually think Julianne Hough needed a makeover, since her recent split from Ryan Seacrest, her bikini bod has been getting better and better.

julianne hough bikini

Not only has this actress lost a few pounds and cut her hair shorter, but she's also gained a whole lot of muscle. Plus, she's all about glitzy and fun bikinis now that she's single and ready to mingle!

Jessica alba bikini

After Jessica Alba gave birth to Haven in the summer of 2011, she lost the weight relatively quickly. Exhibit A: This left-hand photo was taken within a year of giving birth to her second daughter. But her return to tough chick, hard body status took just a little bit longer.

jessica alba bikini

By the spring of 2013, Jessica Alba was back in fighting form. Honestly, how great does she look in this little bikini?

vanessa hudgens bikini

Vanessa Hudgens gained a few extra love pounds when she started dating Austin Butler. It wasn't a bad thing (she still looked pretty great in this neon bikini), but her usually fit figure wasn't as defined as before. But fast forward to a year later …

vanessa hudgens bikini

And Vanessa had clearly gotten her groove back! She flaunted her much trimmer bod while dancing on board a yacht off the coast of Italy this summer.

gisele bundchen bikini

Just a month after giving birth, Gisele Bundchen had an enviable bikini body. While in Costa Rica with her new daughter Vivian, this supermodel showed she only had a few pregnancy pounds to get rid of.

While shooting scenes for "The Fighter" in 2009, Mark Wahlberg's enviable body was caught looking more, well, funky than hunky.

It's amazing what sun-kissed skin and a few pushups can do for Mark Wahlberg. While in Miami filming "Pain and Gain" on April 11, 2012, he brought out the big guns to prove to us all that he's still in fighting shape.

In 2006, Nicole Richie frightened Hollywood (and the world!) when she was spotted with this shockingly frail frame while frolicking on the beaches of Malibu.

nicole richie black bikini

What a difference a few years made! Marriage and motherhood must be treating this "Fashion Star" well. In April 2013, Nicole Richie enjoyed a getaway in St. Barths showing off her lean and toned bikini bod in a tiny black bikini.

In the summer of 2011, LeAnn Rimes' scary-slim body was headlining the blogosphere after these photos of her on the shores of Malibu surfaced while her beautiful voice sat on the sidelines.

To the delight of us all, LeAnn Rimes showed off a curvier figure in early 2012 — and a new bikini to match.

Self-proclaimed "former fat person" Kelly Osbourne covered up on a Hawaiian family vacation on Jan. 3, 2010, proving how hard she struggled with her weight and confidence.

Just 10 months later, Kelly had lost 50 pounds with the help of "Dancing With the Stars." Reborn as a svelte woman, she proudly posed for Shape magazine in a super-sexy red bikini.

On March 27, 2010, three months after delivering her son Hank Jr., Kendra Wilkinson wasn't quite ready to strip down to a bikini despite having shed the bulk of her baby weight. A year and a half later, though, Kendra is back in "Girls Next Door" condition.

"Go, Kendra! Go, Kendra!" Wilkinson's determination to lose those last few straggling post-baby pounds proved to be a huge success when she returned to the exact same pool on March 24, 2012.

Serena Williams is most famously known for her killer athleticism on the tennis court, but it looks like this Olympian spent a little less time at the net and more time soaking up the sun while in Miami on April 16, 2011.

OK, we take it back! Serena Williams, put us all to shame when she was spotted flaunting those grand slam abs just three months later. Now, that's motivation to hit the gym.

Hollywood bombshell Megan Fox is known for her curves, but she looked frighteningly skinny in this tiny black bikini while cooling off in the Hawaii surf in December 2010.

Curv-a-licious Megan Fox is back! And she continues to do what she does best, using her stunningly good looks to make grown men go weak in the knees during her 2011 Hawaiian vacation with her hunky husband, Brian Austin Green.

We gotta hand it to "Extra" host Maria Menounos. The beach bod she showed off on the shores of Miami in May 2011 was pretty fantastic, but in the coming winter months, she toned up even more.

When she lost a bet to Mario Lopez, Maria was forced to strip down to a New York Giants bikini while filming "Extra" in Times Square on Feb. 6, 2012. But in displaying her tanned, toned bod, the hot brunette still came out on top, in our opinion.

Generally speaking, there's not much to complain about when it comes down to Zac Efron and his washboard abs, which he proudly displayed on the set of "Charlie St. Cloud" on Aug. 11, 2009. But can you imagine how he'd look like with a few extra pounds of muscle?

Lucky for us, Zac Efron's showed off his new muscular body in the summer of 2011 after prepping for his new role as an über-toned Marine in "The Lucky One."

Sure, Holly Madison looked great at the Wet Republic Ultra Pool at the MGM Grand Resort in Las Vegas on May 22, 2009, but click though to see what five extra minutes in the beauty department can do for this "Peepshow" star.

Going from bland to glam was super-easy for Holly Madison when she arrived at the same place just one year later. All she had to do was throw on a cute pair of heels and touch up her spray tan.

On this rare occasion, Denise Richards looked slightly less than model-perfect while vacationing with her family in Hawaii on Dec. 31, 2010. But we're just going to blame that on ex-hubby Charlie Sheen's monstrous meltdown.

And here's what payback looks like. Reminiscent of her steamy "Wild Things" pool scene, Denise Richards recently posed for a few sizzlin' hot bikini pics in Malibu on May 1, 2012.