Lena Dunham has been busy filming the upcoming fifth season of her HBO hit Girls in New York City the last few months.

So it's no surprise that when a paddle board race to benefit the Breast Cancer Research Foundation was held in the Hamptons on Saturday morning, the charitable 29-year-old was sure to attend.

She joked about the event on Friday after sharing an informative link, listing a few professional athletes that would also be in attendance and writing: 'I'm up against Gabrielle Reese and Laird Hamilton in a water sport race so DEFINITELY BET ON ME.'

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Looking bright: Lena Dunham sported a colorful, geometric print bikini as she attended a paddle boarding race in the Hamptons on Saturday which benefited the Breast Cancer Research Foundation

Lena wore a colorful, bright green, orange, and pink geometric print bikini for the race, which she at times, covered with a long-sleeved white T-shirt she received for being a participant.

Following the race Lena tied the shirt around her waist, and showing off her stylish swimsuit and curves as she walked barefoot around the beach.

She appeared to be going make-up free for the outing, during which she sported a smile as she stopped to speak to a few reporters.

She made it! Lena was all smiles as she was spotted darting onto the beach past the bright pink finish line

In good spirits: The HBO star sported a wide grin as she hung out on the beach following the race

Cooling off: Following the race Lena hydrated with a bottle of water and sported her participants' T-shirt tied around her waist

The HBO star also ran into celebrity trainer Tracey Anderson, who she recently took to Instagram to praise.

Lena wrote: 'Thank you @tracyandersonmethod for showing me the light,' alongside a photograph of her in a sports bra and colorful leggings.

The actress has been training with Tracy, and gushes it has 'helped with my anxiety in ways I never dreamed possible.'

In good company: The TV star ran into her trainer, Tracey Anderson, at the Hamptons event on Saturday

Showing some love: Lena planted a kiss on the trainer's cheek, as the two posed for cameras

Pretty in pink! Lena (R) sported a Paddle & Party in Pink T-shirt for the event, while Tracey (L) showed off her sculpted abs in a tiny pink bikini

The pair sported smiles as they posed alongside each other at the Hamptons event on Saturday, with Lena planting a kiss on Tracey's cheek in one shot.

Tracey went barefoot as well, and showed off her toned abs in a tiny, hot pink bikini, wearing her blonde tresses pulled back in a ponytail.

She at times hid her eyes behind a pair of stylish, two-toned sunglasses, and sported a white, shell necklace.

Happy it's over: Though the star was glad to be supporting the Breast Cancer Research Foundation, she posted that she struggled a bit with the paddle boarding race, and was likely happy to be back on land

Giving it her all: Lena looked happy as she was spotted paddling during Saturday morning's race

Struggling? The star later admitted on Instagram that she needed a bit of rescuing from surfer Laird Hamilton

Earlier in the day Lena was spotted giving it her all as she took to the water on her paddle board for the race.

She at times looked a little hesitant, pulling an uncertain face as she rowed, though the star kept her spirits up the entire time, and later waved at fans as she made her way back to shore.

Following the race she took to Instagram to share a snap from the ordeal, admitting she was a bit stuck while out on the water.

Fan friendly: Despite struggles on the paddle board, Lena still pulled a grin and waved to fans

Getting in position: The actress assumed the position as she got ready to begin the day's paddle boarding race

She shared a somewhat blurry photo of her standing on her board, as surfer Laird Hamilton approached from a few feet away.

'It's hard to tell from this blurry shot, but this is an image of Laird Hamilton coming to save me. He is literally King Triton and as I struggled to complete BCRF's Paddle for Pink (an amazing event to support breast cancer research) he appeared as if from the ocean's depths and guided me to the finish line,' Lena wrote.

'I kept screaming "will I make it?!" like we were in a disaster movie. He said "yes, Lena, we will." Ladies, there are still a few heroes we can count on... #ThankYouLaird #paddleforpink #3miles'

A little help from her friends: Lena said Laird - 'literally King Triton' - 'appeared as if from the ocean's depths and guided me to the finish line'

Star-studded: The Real Housewives of New York City's Bethenny Frankel also made an appearance on Saturday

The Real Housewives of New York City star Bethenny Frankel also showed her support on Saturday.

She attended the Hamptons event sporting a long-sleeved navy blue, green, and white striped crop top, which she coupled with a pair of coordinating bathing suit bottoms.

Bethenny wore her short, brunette tresses in soft waves, and hid her eyes behind a pair of over-sized sunglasses.

She accessorized with a stylish silver watch with a white band, and went barefoot as she walked along the beach.