I’ve been doing Pilates for 15 years, and this simple core exercise humbles me every single time

(Image credit: Shutterstock) I’ve been practicing Pilates for 15 years: it’s gotten me to the start line of six (nearly seven) marathons and helped me rebuild my core following the birth of my son two years ago. But more importantly, it’s helped me stay injury-free for years, giving me the functional strength to carry my toddler on my hip and the endless bags that come with being a mom.One exercise that humbles me every single time is the dead bug. This simple-looking move is one of the best ways to train anti-extension core stability — in other words, you’re teaching your deep core to hold your spine and pelvis completely still as your arms and legs move.Unlike sit-ups and crunches, this move won’t put your spine under pressure, making it suitable for beginners. That said, if you’re pregnant, postpartum, or you’re currently recovering from an injury, it’s always best to seek personalized advice from a qualified professional.How to do a dead bug Let’s start with how to do a dead bug with perfect form. You won’t need any additional equipment for this move, but to add resistance once it feels easy, hold a set of light dumbbells. Here are the best adjustable dumbbells for working out at home. (Image credit: Shutterstock)Lie on your back. Use a yoga mat to make things more comfortable.Engage your abs and press your lower back flat gently toward the floor. Imagine you have a piece of paper under your lower back and you don’t want someone to be able to pull it out.Raise your legs into tabletop position — this means your arms are straight to the ceiling, with your elbows in line with your shoulders, and your knees are bent at 90 degrees.Slowly and with complete control, extend your left leg away from your body, stopping when it's a few inches off the floor. At the same time, extend your right arm away from your body. Think about reaching out as far as you can.Pause here for a few seconds, then bring both back to your starting position, repeating on the other side.Keep alternating sides, exhaling as you extend, inhaling as you return to tabletop.Opt for 10 repetitions on each side.If you notice your back arching off the mat, you’re not engaging your core. Keep your arms still and just extend your legs, taking them out at a 45-degree angle. The lower your leg drops to the floor, the harder this exercise is.What are the benefits? This exercise works your deep core muscles, also known as your transverse abdominis. Far from sculpting visible abs, these deep muscles act as your body’s corset, protecting your spine from injury. Your obliques and outer core will also get a workout here, too.If, like me, you’re a runner, this exercise helps build the cross-body coordination you’ll need for running and walking. You’ll be building deep stability in your core.Get instant access to breaking news, the hottest reviews, great deals and helpful tips.Bruno Pontes, a certified personal trainer at Muscle Booster, adds, “The dead bug is a great starting point for functional core training because it teaches you to keep your core stable while moving your arms and legs independently.“The key is to move slowly and maintain control rather than rushing through the repetitions. It’s a relatively simple exercise, but it can help develop core stability, coordination and body awareness, making it a useful movement for people of different fitness levels.”Follow Tom's Guide fitness on Instagram for more workouts, routines, tips, and tricks. Follow Tom's Guide on Google News and add us as a preferred source to get our up-to-date news, analysis, and reviews in your feeds. Alternatively, you can read our content on the Tom's Guide app available now for iOS and Android. Subscribe to Tom's Guide on YouTube and follow us on TikTok. More from Tom's GuideI teach people how to be more mobile: 3 low-impact back and shoulder moves that build stability and strength after 40I teach people how to be strong and mobile: this is the one exercise I regret ignoring for yearsI teach people over 50 to be mobile: 3 low-impact moves that build more stability than a 30-minute walk Jane McGuire is Tom's Guide's Fitness Managing Editor, which means she looks after everything fitness-related - from running gear to yoga mats. An avid runner, Jane has tested and reviewed fitness products for the past ten years, so knows what to look for when finding a good running watch or a pair of shorts with pockets big enough for your smartphone.