In Part IV of our full-body workout series we’re bringing the attention to your core. This abs workout helps to strengthen and tone the look of your tummy with just three moves! Let’s face it: whether we’re rocking bikinis or not, we all want abs— or, at least a toned-looking core. And if anyone knows a thing or two about achieving a toned tummy, it’s personal trainer, social media influencer, and friend of skincare.com, Brianna Sky of @BSKYFITNESS. When she’s not busy training clients and taking care of her complexion through her trusty skin care regimen and well-balanced diet, she’s focusing on strengthening her core and getting ready for her next bikini competition. Lucky for us, she shared a few ab exercises to help us do the same. Ahead, we share three at-home ab workouts to try this fall.LEG RAISESMeant to target your abs and hips, straight leg raises are simple and require no gym equipment. Start by laying on your back— we suggest doing this on a cushioned yoga mat to ensure that you are comfortable and your back is supported— with your arms straight against the sides of your body and your legs straight and up in the air, pointing upward (your goal is to create a 90° angle or “L” shape with your body). Now, engage your abs and slowly lower your legs down towards the ground. Although you are lowering them to the ground, you want to make sure to keep them off the ground during each set to ensure that your abs remain engaged. Do three sets of fifteen reps. Don’t forget to rest and drink water during each set!WINDSHIELD WIPERSActivate your core and target your obliques with three sets of thirty windshield wiper reps (fifteen on each side). To do so, you’ll need a yoga mat and an area in your home or backyard that is big enough for you to stretch your wingspand out comfortably. Start by laying on your back with your arms spread outward. Then, bring your knees into a bent table top position, like the image shown above. Now, engage your core muscles and start to slowly swing your hips from side to side— start by twisting to the left side, then bring your knees back to center before twisting to the right side. Make sure to keep your bottom leg from touching the ground during each set.STRAIGHT LEG SIT-UPSSit-ups come in different variations in order to target specific areas in your core. Straight leg sit-ups kill two birds with one stone by targeting both the Rectus abdominis— or the topmost area of your abs— and the obliques. To start, simply lay on your yoga mat with your legs straight and your hands behind your head— this allows the neck and head to feel supported during the exercise. Then, using your abdomen, bring yourself up into the 90° angle or sitting position, pictured above. Now, slowly make your way back down to your mat and repeat fourteen more times. Like the other exercises in this workout, you’ll want to complete three sets of fifteen reps.Editor’s Note: At least 10 minutes after finishing your workout hop in the shower to cleanse your skin of the excess sweat and then follow with moisturizer and the rest of your skin care routine. Taking your workout outside? Don’t forget a broad-spectrum SPF of 30 or more!ICYMI: Part I: 3-Move Arm Workout For Sexy-Looking ArmsPart II: 3 Legs Workouts For Toned-Looking LegsPart III: 3 Glute Exercises For A Better-Looking BootyPart V: At-Home Back Exercises To Help Improve Posture