Kim Kardashian just celebrated her younger sister Khloé's birthday. They chose to celebrate with a tropical vacation. Kardashian just posted a new set of photos of the two of them wading in the ocean. They wore matching black bikinis and kept their blonde hair down. Kardashian captioned the post, "Khloé's BDay trip." How does she stay so fit? Read on to see 5 ways Kim Kardashian 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!

Kardashian revealed in a Vogue interview that she is changing some of her habits. She says that she is living a healthier lifestyle. "I'm going to eat well. I'm going to work out. I'm going to have more fun, spend more time with my kids and the people who make me happy."

After her divorce from Kanye West, Kardashian told Vogue that she is putting herself first and making herself happy. "I think in the last two years I decided, I'm going to make myself happy. And that feels really good. And even if that created changes and caused my divorce, I think it's important to be honest with yourself about what really makes you happy. I've chosen myself. I think it's okay to choose you." 

Kardashian tells Vogue that she has a lot of focus in her life. "I just try to live my life and be happy for people," she says. "And I think when you just live your life like that, you block it out. It's like a racehorse that puts on blinders so they can see clearly and straight. You've got to just be that racehorse, put on those blinders, and go. And if you start trying to see to the right or the left of you, you're going to trip up."

Kardashian makes sure to workout on a regular basis. She tells Women's Health that she plans ahead the night before. "I will lay my clothes out the night before so when I sleep in, I'll wake up at 5.53[am] instead of 5.45, and I just know my outfit is there," she says. "I have a toothbrush and my toothpaste all ready to go, laid out by my sink. I just have to brush my teeth and go to the gym."df44d9eab23ea271ddde7545ae2c09ec

Kardashian works with personal trainer, Melissa Alcantara, to help herself stay in shape. Alcantara revealed some of Kardashian's workout secrets to Women's Health. She says that she has the socialite do a majority of weights with some cardio. "Eighty-five percent of our training is weight training, and the other 15 is made up of cardio."