Kim Zolciak-Biermann and Ariana Biermann in Bathing Suits "Party"

Reality star Kim Zolciak-Biermann just posted a throwback photo on Instagram. In it, Kim and her daughter, Ariana, posed in matching black bikinis. Kim captioned the post, "Me and my baby @arianabiermann on my birthday back in May!!! RED SOLO CUP LETSSSS HAVE A PARTY.  DONT BE TARDY (before you ask… I'm 5'8 and Ariana is 5'3.)" How do they stay so fit? Read on to see 5 ways Kim Zolciak-Biermann and Ariana Biermann stay 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!

Ariana has no time for haters, especially when they are talking about her body. When someone accused her of having an eating disorder, Ariana hit back on her Instagram story. "I do not have an eating disorder. I worked my a** off to get to where I am today. I am not sick. This is ridiculous and awful to say to someone. Stop commenting on people's bodies and worry about yourself."

Kim makes healthy eating a priority. She revealed her diet on her Instagram story. "No pork, no beef, sometimes chicken, pasta, chocolate, veggies and wine." "It's never too late to become healthier, and an important part of getting there is to eat healthier. Did you know that by eating a rainbow of colors of fruits and vegetables you can protect your health against such diseases as cancer, heart disease, diabetes and even poor eyesight? The different colors of fruits and vegetables provide you with powerful antioxidants that can boost your immune system and provide protection," says the Mayo Clinic.

Kim revealed some of her wellness secrets in this Instagram post. She wrote that one of her favorite ways to workout is by running. "I run three to four miles five times a week. I have ALWAYS loved to run." Dr. Carlos Uquillas, an orthopaedic surgeon who specializes in injury prevention at the Cedars-Sinai Kerlan-Jobe Institute,  notes that running:

• "Increases endorphin levels – Endorphins are your brain's natural feel-good chemicals, which boost metabolism and provide a positive sense of wellbeing often referred to as a "runner's high."
• Enhances sleep – Better sleep improves metabolism, organ function, and physical and mental energy.
• Lowers risk of depression – Depression is one of the most common mental health conditions and it can make other illnesses worse."

In her Instagram post, Kim revealed that she lives an active life. She says that this lifestyle helps her stay in shape. "From the time I get up, to the time I go to bed, I rarely sit down," she writes. "I don't do elevators, I'd rather walk 30 flights." "You don't need expensive gym equipment to get a good workout. Research shows that stair-climbing helps strengthen and tone your leg muscles. It keeps your leg arteries flexible, allowing blood to move more easily. Better blood flow in your legs equals a healthier heart and body," says the Mayo Clinic.

Kim is open about her struggles with her health. She has had heart problems and anemia. She revealed in her Instagram post how she treats her anemia. "I'm anemic and get iron IVs for it often," she explains. "Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body's tissues. Having anemia, also referred to as low hemoglobin, can make you feel tired and weak," says the Mayo Clinic. "There are many forms of anemia, each with its own cause. Anemia can be temporary or long term and can range from mild to severe. In most cases, anemia has more than one cause. See your doctor if you suspect that you have anemia. It can be a warning sign of serious illness."