Forget sit-ups — these bodyweight ab exercises will define your core

a photo of a woman doing a side crunch
(Image credit: Getty/Javier Sanz)

Tired of the same old, monotonous ab exercises? You aren’t alone. Thankfully, there are ways to spice up your core workouts while keeping on top of your fitness goals.

Fitness coach and Sweat app co-founder Kayla Itsines has devised an invigorating ab routine that incorporates fresh moves into your workouts, challenging your core muscles in new and engaging ways. By incorporating unique variations and stimulating combinations, this workout not only adds excitement but also ramps up the intensity.

Before you get stuck into Itsines’ routine, remember that getting visible abs forms one part of core training, and there are various other reasons to strengthen these muscles; a strong core improves posture, helps you lift heavier weights and supports your torso and spine during movement. If building visible abs is your goal, you'll need to focus on your overall body fat percentage — here's how to calculate your body fat percentage, and why it matters

6 exercises to strengthen and define your abs

The workout combines six challenging exercises that will leave your core burning and abs sore the following day. You will complete 12 repetitions of each exercise and 24 (12 on each side) for the final exercise, which is the side plank and crunch. If you can, Itsines recommends completing the full circuit three times overall.

The routine includes ab bikes, leg raises, mountain climbers, side-to-side half burpees, inchworm, and side plank and crunch. All exercises are worth completing but below we dive into why the final three moves are particularly effective when training the abdominal and core muscles.

Side-to-side half burpee

To perform a side-to-side half burpee, start in a standing position and lower into a squat. Place your hands on the floor, kick your legs back into a plank, then jump both feet towards one side and back to the center. Repeat the jump to the opposite side. This exercise engages the abs, arms, and legs, making it a dynamic and effective move for a full-body workout.

Inchworm

To do an inchworm, begin in a standing position with feet hip-width apart. Bend forward at the waist, placing your hands on the floor. Walk your hands forward until you reach a plank position. Pause briefly, then walk your hands back towards your feet, returning to the starting position. The inchworm exercise targets the core, shoulders, and hamstrings while promoting flexibility and stability throughout the body.

Side plank and crunch

To perform a side plank and crunch, start in a side plank position with your forearm on the ground and your body in a straight line. Engage your core and lift your top leg toward your chest while simultaneously crunching your elbow toward your knee. Return to the starting position and repeat on the other side. This exercise targets the obliques and abdominal muscles, helping to improve core strength, stability, and overall abdominal definition.

What are the benefits? 

Regularly performing ab routines can bring numerous benefits to both aesthetics and physical fitness. Exercises, like the ones performed in Itsines’ routine, can help sculpt and define the abdominal muscles, creating a more toned appearance. Beyond aesthetics, a strong core provides stability and support for the entire body, improving posture, balance, and overall functional fitness. 

However, it's important to remember that a well-rounded workout routine should incorporate exercises targeting all muscle groups, including cardiovascular and flexibility training. By maintaining a balanced approach, you can optimize your overall health, strength, and well-being while reaping the rewards of a strong and toned midsection.

More from Tom's Guide

Jessica Downey
Senior Fitness Writer

Jessica has been a fitness writer at Tom’s Guide since 2023, bringing three years of experience writing about health, fitness, and the great outdoors. Her passion for exercise began during her childhood, where she spent weekends hiking and competing in local athletics club events. After earning a master’s degree in journalism from Cardiff University, Jessica found the perfect way to combine her love of storytelling and fitness into a career.

Jessica is passionate about testing fitness gear and tech, using her reviews to help readers make informed buying decisions. She ran her first marathon in April 2024, finishing it in 3 hours and 48 minutes. Through her training, she’s developed a deep understanding of what it takes to grow as a runner, from effective workouts and recovery techniques to selecting the right gear for every challenge.

When she’s not at her desk, Jessica enjoys spending time in the kitchen crafting new recipes, braving cold water swims and hiking.

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