Yolanda Hadid, 52, Bares Her Perfectly Toned Booty in Lakeside Photo

In case you were wondering where Gigi and Bella Hadid got their knockout looks, the answer has been made undoubtedly clear: their mother (and former supermodel), Yolanda Hadid.

Hadid, 53, shared a photo Tuesday morning watching the sun rise at Lake Constance, baring her toned booty in a dock-side picturesque scene. She wore a lacey grey thong with a matching grey sweatshirt as she looked over the serene water.

"It's a beautiful, magical sunrise at the lake this morning," she wrote in the photo's caption.

Hadid has been open about her battle with Lyme disease since her diagnosis in 2012, and wrote in the caption that swimming in Lake Constance's waters were good for her treatment.

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"The water is quite cold but its [sic] such a great way to combat inflammation and feel the connection to Mother Earth," she wrote, adding the hashtags #LakeConstance, #MorningSwim, #HealingPower and #LovingLife.

The Real Housewives of Beverly Hills alum told PEOPLE last year that she was still actively searching for a cure to her chronic disease.

"I’m like a little scientist at work," she said. "I want to figure this out. I want to be 100 percent functioning like a normal person. I deserve it, I want it and I’m going to get it."

❤️Some Dutch childhood shenanigans......... #Joy #HealingSpirit #Konstance

A post shared by YOLANDA (@yolanda.hadid) on

"Right now I am no gluten, no dairy, no grains, nothing that turns into sugar, no caffeine, no alcohol, no black tea," she said. "It’s boring, but I would eat bark for a year if it would save my life. I’ll do anything."

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The Netherlands-born star, who is also mom to model son Anwar Hadid, frequently showcases her active lifestyle on Instagram withher 2.4 million followers, whet her swimming in Lake Constance, biking through Konstanz City or eating from her organic home garden.

Photo Credit: Instagram / @yolanda.hadid