Britney Spears Rocks Two Bikinis at Six Flags Hurricane Harbor

Waterpark fun! Britney Spears rocked a bikini for a day of fun in the sun with her two sons, Sean, 7, and Jayden, 6, while visiting Six Flags Hurricane Harbor in Southern California on Tuesday, July 30.

Wearing a black and white striped bikini, the "Ooh La La" singer was all smiles while she walked through the park, her hair kept in a blue baseball cap. The former X Factor judge -- who told Shape in May how she stays fit -- showcased her toned legs and flat abs while walking the park.

A day later, on Wednesday, July 31, the pop princess donned a pink bikini, again showing off her sexy physique at the park. 

Britney Spears rocked a pink bikini on Wednesday, July 31.
Credit: TMZ

In May, the 31-year old revealed it gets harder and harder to keep her body in tip-top shape. Of her love/hate relationship with exercising, she revealed to the magazine, "I like it, then again, I hate it. Dieting is tough...because my specialties are spaghetti, brownies, and chocolate chip cookies."

No doubt the mom enjoyed a break from yoga and cardio for slides and rides with her sons. After leaving the park, she tweeted, "So much fun spending the day at the water park! My boys had a blast," adding a smiling face.

Snooki Shows Off Bikini Body in High-Waisted Swimsuit: Picture

Home is where her family is! Nicole "Snooki" Polizzi looked excited to be frolicking in the warm waters of the Jersey Shore on Monday, July 29, with fiance Jionni LaValle and 11-month-old son Lorenzo in tow.

The fit mommy, 25, paired a retro-style black-and-white striped bikini top with high-waisted black bottoms for the afternoon outing, a set of oversized glasses perched on her nose. LaValle, meanwhile, kept things casual in an aqua-colored tank top and blue-and-black board shorts.

Tiny Lorenzo looked less than pleased about the family fun, however, and was snapped crying as his doting parents tried to cheer him up. 

Polizzi's head-turning outfit on Monday is only the latest in a high-waisted streak that the former reality star has seemingly adopted this month.

On Sunday, July 28, the young mom stepped out for errands in high-waisted light wash mom jeans and a studded black fanny pack that drew jeers online. Polizzi didn't take the criticism lying down, however.

"Everyone hatin on my mom jeans and fanny pack…sorry I was born in the wrong decade," she tweeted on Monday.

One thing that even her biggest haters can agree on, however, is that the former self-professed "meatball" has been working hard to shed the pounds since giving birth to baby Lorenzo.

"When I work out, that's when I feel good -- when I'm strong," she told Us. "I've never been this strong in my life."

Jason Segel Explains Weight Loss, Discusses End of How I Met Your Mother

Jason Segel looked healthy and handsome during the CW, CBS and Showtime's Summer TCA Party in L.A. on Monday, July 30. The clean-shaven actor, 33, looked trim in a gray suit while posing for photographers on the red carpet. According to Segel, he's been getting in shape for his next movie, Sex Tape, costarring Cameron Diaz.

"I've just been living healthy, exercising, eating right -- no more midnight pizzas," Segel told Us Weekly. "This time when I take my shirt off, I've made a promise to myself, it doesn't have to be funny."

According to Segel (who split with Michelle Williams earlier this year), "I took heat for Forgetting Sarah Marshall, where I was completely nude. But different characters require different body types." Production on the raunchy comedy begins in September. "It is R-rated," he teased, "and I'm not in shape for no reason."

In the meantime, Segel is focused on the ninth and final season of How I Met Your Mother (premiering Sept. 23 at 8 p.m. EST on CBS). "My favorite moments have just been watching my castmates grow up. We have been together for a decade now and a lot of life stuff has gone on for everybody," the star said. "It's like a real family. It's the longest I've known any group of people besides my family."

Segel wants to embrace the moment instead of worrying about the next phase of his career. "I'm just keeping myself busy," he told Us. "I'm not thinking too much about the future."

Gwyneth Paltrow On Bad Cleanse Experience: It "Left Me Hallucinating After 10 Days"

It's no secret that Gwyneth Paltrow is a fan of diet and exercise trends -- but one that she tried in her 20s came at a high cost: "hallucinating after 10 days."

"I've done juice cleanses in the past, and in my twenties I did the Master Cleanse, which left me hallucinating after 10 days," she admitted in a column she penned for the UK's Telegraph. "Be aware: a juice detox can crash your metabolism and lead to future weight gain."

The Goop founder dished out that helpful piece of advice and more for the paper on Monday, July 29. According to the mother-of-two (to kids Apple, 9, and Moses, 7, with husband Chris Martin, 36), it's also more productive to measure weight loss in inches, not pounds.

"There is something punitive about weighing yourself," she wrote. "It can leave you vulnerable to shame and guilt, and it messes with you psychologically. Women naturally gain and lose weight during their monthly cycle anyway, so it can be more realistic to monitor your body shape with a measuring tape."

This isn't the first time the lifestyle guru has offered her unsolicited advice to fans. Paltrow, 40, also recently chatted with British Cosmopolitan about her take on aging and Botox.

"I don't like Botox. I think on some faces it works, but it's when you can really see it that it start to look fake," she said. "I love how French actresses age but don't really do anything about it -- it's beautiful."

Paltrow instead prefers to stay fit with a regular workout routine -- the Tracy Anderson Method -- and a balanced diet, with the occasional cheat.

"Allow yourself programmed treats -- I often have a glass of red wine in the evening and smoke a cigarette on a Saturday," she advised readers in the Telegraph column. "I love those moments because they are just the right amount of naughty."

"That balance keeps you vibrant," she concluded. "You have to live your life, after all."

Jennifer Aniston Stripper Diet: How She Prepped for Sexy We're the Millers Role

Jennifer Aniston is a lean, mean kale-eating machine! In her new comedy We're the Millers, the 44-year-old went on a strict diet to get into even better shape than she usually is to play a stripper.

"I was on a very like, you know, greens and vegetables and lean proteins and kale," Aniston told Access Hollywood of her diet plan. But the Friends star adds that she "did eat" on the day of her big stripping scene, where she strips into lingerie in front of costars Jason Sudeikis, Emma Roberts and Will Poulter. "When I really wanted to have a cheat day," she said, "I had to have a kale chip."

In addition to eating right, Aniston also had to focus on getting an injured knee ready to handle the sexy moves. "It wasn't easy because I'd just had knee surgery a month and a half before. It was a little bit tedious. And then also just getting trained physically -- I was really in shape then," she told USA Today. "I was in the kind of shape I don't enjoy being in because it feels a little too fit."'

Unfortunately, Justin Theroux's fiancee still needs to have another knee surgery done "in a about a month." "I have a hole in a tendon that's leaking fluid," she shared. "Is that pleasant? It hurts. It feels creepy. But let's not talk about that."

Even though she got her body into amazing shape to strip in the Rawson Marshall Thurber-directed film, Aniston was still nervous that her "kibbles and bits" would accidentally be exposed -- so she doubled up on lingerie!

"I had no taping. I really just doubled my bras. I had a thong and then two pairs of underwear," Aniston told Access Hollywood. "Why I thought that was going to help protect anything is beyond me. Because, that's just like ridiculous . . . I was like, 'No, I need three bras! I need three bras because God forbid that one, if it's gonna escape!'"

Jamie Lee Curtis Wears Low-Cut Black Swimsuit at Age 54

Jamie Lee Curtis has never looked better! The actress and Activia spokeswoman, 54, showed off her incredible beach body when she donned a low-cut black swimsuit during a Hawaiian getaway with friends on Thursday, July 25. Curtis, who next appears in the Veronica Mars movie, also wore wet shoes and a silver necklace while wading through the Pacific Ocean.

Though Curtis has admitted to getting plastic surgery in the past, she has since learned to love her looks the older she gets. "Aging is as natural as a baby's softness and scent," the Halloween star wrote in a March 2012 blog for The Huffington Post. "Aging is human evolution in its pure form."

"Genetics are the key to aging," continued the Hollywood veteran, best known known for roles in A Fish Called Wanda and True Lies. "I now resemble both my grandmothers, where when I was younger I didn't see them at all, and if I am now looking at myself with the eye of one who can look back at photos and movies and commercials and miss the good old days, that would be a wasted life. We are ALL going to age and soften and mellow and transition. All of us, if we are lucky enough to make it through this hard life into older adulthood."

Curtis -- mom to daughter Annie, 27, and son Thomas, 17, with director husband Christopher Guest, 65 -- has long been an advocate of embracing her natural looks. Covering the September 2002 issue of More, the star asked to be photographed without makeup, a manicure, hairstyling or fancy clothes.

"There's a reality to the way I look without my clothes on," she told the magazine. "I don't have great thighs. I have very big breasts and a soft, fatty little tummy. And I've got back fat. People assume that I'm walking around in little spaghetti-strap dresses. It's insidious -- Glam Jamie, the Perfect Jamie, the great figure, blah, blah, blah. And I don't want the unsuspecting 40-year-old women of the world to think that I've got it going on. It's such a fraud. And I'm the one perpetuating it."

In the interview, the Freaky Friday star copped to getting liposuction and Botox -- but said neither procedure improved her appearance. "None of it works," she said. "None of it."

"Ten years ago, before anybody did that, I had fat taken from underneath my eyes because I was on a movie and I was puffy," Curtis recalled. "And I remember the cameraman saying, 'I can't shoot her now.' I remember being mortified. And yet, you know what? Nobody tells you if you take fat from your body in one place, it comes back in another place. All of these 'betting' experiences are not without risk. And there is this illusion that once you do it, then you'll be fine. And that's just horsesh-t. I looked worse."

Nick Jonas Shares Shirtless Picture on Instagram, Unveils Buff Body

Who knew Nick Jonas had such a buff body? The Jonas Brothers singer, 20, showed off his impressive physique via Instagram on Tuesday, July 30. "I never do this, but. . ." the pop star wrote in the photo caption. "Healthy living and fitness update. Post workout picture. #diabeticinshape #2.0."

Posing shirtless and exposing his hairy chest, the "First Time" singer struck a seductive pose and flexed his biceps. The image immediately elicited a slew of excited responses from Jonas' fans. "This totally made me feel better after my crappy day at work," one user wrote. Another admirer pleaded, "Marry me and make babies!"

Jonas -- single since his February 2012 split with Australian pop star Delta Goodrem -- has been tweeting about his fitness quest since the spring. "Workout done. Food. Then set," he told his followers on Friday, May 10.

Though he hasn't detailed his exact workout routine, Jonas did tell Us Weekly about his healthy eating habits at Z100's Clear Channel radio studios in New York City on Thursday, July 25. "I love dried kale with seasoning on it," he revealed.