Sisters and models Olivia and Sophia Culpo are really close. They share a lot of things, like swimsuits, apparently! On Olivia's Instagram stories, she shared videos of her sister in a Devon Windsor swimsuit, implying that she "borrowed" it from her. Or did she swipe it? Olivia wrote on the story, "I'm onto you." How do these siblings stay so fit? Read on to see 5 ways Olivia and Sophia Culpo stays in shape and the photos that prove they work—and to get beach-ready yourself, don't miss these essential 30 Best-Ever Celebrity Bathing Suit Photos!

Sophia is currently studying nutrition and health at Boston University, so she knows how to take care of herself. She broke down some of her tips and secrets in an interview with Health Bar Journal. Sophia says that she believes in eating a balanced diet, as opposed to a restrictive one. "I don't believe in 'bad' foods or restrictive diets in the long-term. Elimination diets can be helpful when diagnosing food intolerances, but long-term restrictions can lead to disordered eating and mental stress. I believe in enjoying your favorite foods in moderation while maintaining a healthy, balanced diet. This avoids binging and feelings of 'guilt' around certain foods. Personally, I eat majority plant-based with occasional fish and white meat and very limited dairy. This is what I've learned works best for my body."

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In her Health Bar Journal interview, Sophia revealed that she believes fiber is an important part of a healthy diet. She says that she makes sure to eat enough fiber each day. "Fiber is a nutrient of concern because so many are deficient in fiber. Fiber fuels a healthy metabolism and keeps your digestive tract healthy by feeding the good bacteria that live in your gut. The gut houses your immune system, so fiber is something we need to help keep us fit and healthy! Plants are great sources of fiber which is why fruits and vegetables are so important in our diet. Processed foods contain very little fiber usually."

Sophia tells Health Bar Journal that she makes sure to drink enough water each day. "Hydration seems pretty obvious but so many skimp on water! Swap out the soda, caffeine, or juice for a healthy glass of water to keep your body properly hydrated and your skin glowing! Water is crucial for healthy digestion and when you're consuming adequate fiber, you need plenty of water to keep your digestion regular and moving."

In an interview with Shape, Olivia revealed how she copes with her endometriosis. She says that she makes sure to take care of herself, and finds new ways to treat her condition. "I'm trying to figure out new ways to heal holistically through what I'm eating and the rest that I'm giving myself. I'm also exploring acupuncture, massages, Chinese herbal medicine, and maybe cutting out caffeine. I'm going to actively try to help people who live with this and not just talk about my experience."

Olivia has great skin, and she makes sure to take care of it. She broke down some of her skin care rituals to Shape. "As for skin care, there are lots of steps. I go to bed with a mask, then I wake up and put on another one to take off the first. I put on a second mask in the morning that's an exfoliant. After that, I use a salicylic acid to remove dead skin. Then I do my moisturizers."