Personal trainer reveals the 5 abs exercises most people are doing wrong — and how to fix your form
Better form, better results
Here at Tom’s Guide our expert editors are committed to bringing you the best news, reviews and guides to help you stay informed and ahead of the curve!
You are now subscribed
Your newsletter sign-up was successful
Want to add more newsletters?
Daily (Mon-Sun)
Tom's Guide Daily
Sign up to get the latest updates on all of your favorite content! From cutting-edge tech news and the hottest streaming buzz to unbeatable deals on the best products and in-depth reviews, we’ve got you covered.
Weekly on Thursday
Tom's AI Guide
Be AI savvy with your weekly newsletter summing up all the biggest AI news you need to know. Plus, analysis from our AI editor and tips on how to use the latest AI tools!
Weekly on Friday
Tom's iGuide
Unlock the vast world of Apple news straight to your inbox. With coverage on everything from exciting product launches to essential software updates, this is your go-to source for the latest updates on all the best Apple content.
Weekly on Monday
Tom's Streaming Guide
Our weekly newsletter is expertly crafted to immerse you in the world of streaming. Stay updated on the latest releases and our top recommendations across your favorite streaming platforms.
Join the club
Get full access to premium articles, exclusive features and a growing list of member rewards.
Performing abs exercises with poor form and still expecting to see results is like expecting your food to cook in the oven without turning the oven on. Proper form is the key ingredient in achieving a strong core and toned abs.
Without it, you’re not only wasting your time but also risking injury. Whether you’re doing crunches, planks, or leg raises, the way you move your body matters more than how many reps you can crank out.
Comfort plays an important role too. Performing abs exercises on one of the best yoga mats can make a world of difference with the extra layer of padding protecting your back and joints from the hard floor. The more comfortable you feel during a workout the more you can focus on your form.
Recently, personal trainer Kayla Itsines shared the do's and don'ts of form for five popular abs exercises on Instagram. Here's what you need to know from the trainer's advice to ensure you're doing them correctly.
Common abs workout mistakes and how to fix them
The advice from Itsines isn't anything too technical, it's just some simple pointers you may have never thought about while performing the five moves discussed. We'll unpack the tips for each exercise but be sure to also watch Itsines demonstrate poor form and good form for each move in the post below.
A post shared by KAYLA ITSINES (@kayla_itsines)
A photo posted by on
Mountain climbers
Don’t: According to Itsines, an easy and common way to compromise your form during mountain climbers is to round your back and look down at your toes. This can cause a strain on your spine and limit the amount of engagement in your core.
Do: Instead, Itsines' easy correction for this common mistake is to focus on maintaining a straight back, neck, and head during the move. Aim to cast your gaze forward, looking ahead of you instead of craning your neck down and looking at your feet.
Get instant access to breaking news, the hottest reviews, great deals and helpful tips.
Abs bikes
Don’t: Itsines says that performing abs bikes with a short range of motion and minimal torso rotation is going to hinder the activation of your abdominal muscles, making the exercise less effective. While it might feel easier doing it like this, the impact the exercise has on your abs isn't going to be great.
Do: Instead, extend your range of motion and ensure full torso rotation with each repetition. What will this look like? You will bring your shoulder towards the opposite knee as you engage your obliques with each twist.
Side planks
Don’t: If your shoulder and elbow aren't aligned during a side plank, then this needs to be fixed. This misalignment will throw off your balance and place unnecessary stress on your shoulder. As someone who has focused on perfecting the side plank, I can say that this small form check can do wonders for how stable and strong you feel holding the position.
Do: To maintain proper form in the side plank, ensure your torso is in a straight line, with your elbow directly under your shoulder. This will stabilize your body and lead to better core engagement.
Half burpees
Don’t: It may sound very basic, but if you forget to engage your core while performing a lively move like this, you will lose stability in your torso and lower the efficiency of the exercise.
Do: Work on extending your back, keeping it straight, and brace your core so that the muscles in there are being put to work.
Straight leg jackknife
Don’t: Many people find it hard to pay attention to how their back is sitting during your jackknifes. If you allow the lower part of your back to arch, you risk putting strain on your spine.
Do: Instead, focus on keeping your lower back pressed firmly against the mat. Engage your core muscles to maintain the correct position as you lift your legs. This will protect your spine and make sure you are engaging the abdominal muscles.
More from Tom's Guide
- Forget tight hips — try this 5-move routine to boost your mobility now
- Ditch the gym — build a stronger lower body with just a pair of dumbbells and 30 minutes
- Lululemon's 'We Made Too Much' section just restocked — 15 items I'd get from $9

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.









