Heather Rae El Moussa in Bathing Suit is "So Sweet"

Heather Rae El Moussa is showing off her baby bump on vacation! The Selling Sunset star, currently expecting her first child with husband Tarek El Moussa, flaunts her bump in a swimsuit via her latest Instagram post. "Baby on board," she captioned the snap, taken on a boat in Greece. "So sweet," said one comment. How does the reality star maintain her fit physique? Read on to see 5 of Heather Rae El Moussa's top do's and don'ts for staying 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!

Heather encourages outdoor activities and maintaining an active lifstyle. "I had a national forest as my backyard. How many people can say that? I would hike down to the creek and swim, go sledding in the winter, and I had a handful of ski resorts to choose from. It might sound dorky, but I love skiing," she told Super Street. 

One of the ways Heather stays fit? She enjoys exercise. "I'm really into fitness and running—I love kickboxing and dancing," she told Super Street. "For big health benefits, aim for these numbers: 2.5 to 5 hours of moderate aerobic activity, or 75-150 minutes of vigorous aerobic activity every week. Want to do more than that? You'll get more health benefits. Try to spread this activity throughout the week," says the Mayo Clinic.

Aim for workouts 7 days a week, mixing up types of exercise to keep it exciting. "Fitness makes me so happy," she added to Women Fitness. "I never look at it like….ugh I have to workout today. I get excited to do it. Right now I do a strength training HIIT class 3-4 times a week. And on the days in between I run 3-4 miles."

Heather tries not to eat out and prepare her own food instead. "I always pack my own food since I am vegan and I always workout no matter what," she told Women Fitness. "Lunch is usually quinoa salad or veggie salad. I snack in between on nuts or a vegan protein bar (which has little ingredients) And I drink tea in between meals. No coffee, I actually have never tried a cup. I do have a sweet tooth though, so I choose to not even have sugar because once I start i can't stop." She also loves protein smoothies. 

Heather encourages taking supplements. "I take fish oil and vitamins daily," she told Women Health. Why is fish oil great? "Omega-3 fatty acids are derived from food. They can't be manufactured in the body. Fish oil contains two omega-3s called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Dietary sources of DHA and EPA are fatty fish, such as salmon, mackerel and trout, and shellfish, such as mussels, oysters and crabs. Some nuts, seeds and vegetable oils contain another omega-3 called alpha-linolenic acid (ALA)," says the Mayo Clinic.