(Image credit: Shutterstock) I’ve been practicing Pilates for the past 15 years — it’s kept me strong enough to run six marathons, and helped me to rebuild my core postpartum. One exercise in particular helps target my deep core, blast my lower abs (a part of the midsection often missed in moves like sit-ups and crunches), and strengthen my hip flexors: the butterfly kick — read on to find out more. As a reminder, what works for me might not be right for you and your body. If you’re a complete beginner, you’re pregnant or postpartum, or you’re dealing with a specific injury, it’s always best to seek personalized advice from a qualified professional. What is a butterfly kick? Butterfly kicks, also known as flutter kicks , are an ab exercise performed lying on your back on an exercise mat. They might look like you’re swimming on land, but you’ll be working your deepest transverse abdominis muscles, which help stabilize your spine and act as your body’s natural corset.…