Why Do I Feel My Back in Ab Workouts

Feeling that annoying strain in your lower back when you’re trying to build your abs is one of the most common frustrations in the gym. You’re putting in the work to get a stronger core, but all you’re getting is a sore back. It makes you want to quit ab training altogether.

Key Takeaways

• The primary reason you feel your back in ab workouts is that your hip flexors are overpowering your abdominal muscles, pulling on your lower spine.
• Common exercises like traditional sit-ups and straight-leg raises often encourage this hip flexor dominance and can lead to back strain.
• Mastering the posterior pelvic tilt-actively pressing your lower back into the floor-is the single most important cue to engage your abs correctly.
• You can fix this issue by modifying exercises, such as bending your knees to 90 degrees during leg raises, to shorten the hip flexors and force your abs to work.
• Replacing high-risk exercises with back-safe alternatives like dead bugs, planks, and bird-dogs will build core strength without compromising your spine.

The Real Reason Your Back Takes Over (It's Not Your Abs)

If you're asking, "why do I feel my back in ab workouts," the answer almost always comes down to a battle between two muscle groups: your abs and your hip flexors. And right now, your hip flexors are winning. Your main hip flexor muscle, the psoas, attaches directly to your lumbar (lower) spine. When you do an exercise like a sit-up or a leg raise, your body needs to flex at the hip. If your abs aren't strong enough or aren't properly engaged, your body recruits the powerful psoas muscle to do the job. Since it's anchored to your lower back, you feel a distinct pulling or straining sensation right where you don't want it.

Think of it like a tug-of-war. Your abs are on one end of the rope, and your hip flexors are on the other. When your abs don't pull their weight, the hip flexors yank the rope-and your spine-into a stressed position. This is especially true for people who sit a lot. Hours of sitting leave your hip flexors in a shortened, tight state, making them overactive and ready to jump in the moment you ask your body to do any sort of crunching or leg-lifting motion.

It’s not that your abs are necessarily weak. It’s that your brain’s connection to them-the mind-muscle connection-isn’t as strong as its connection to your hip flexors. Your body is just taking the path of least resistance. To fix this, you don't need more reps; you need to re-teach your body which muscles to fire first.

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Why Common Ab Exercises Make It Worse

Many of the ab exercises you see people doing are actually terrible for learning proper core engagement. They put you in a position where it's almost impossible *not* to use your hip flexors, especially if you're a beginner.

Traditional Sit-Ups: The full sit-up is mostly a hip flexor exercise. The first part of the movement, where you lift your head and shoulders, uses the abs. But the second half, where you bring your entire torso up towards your knees, is almost entirely driven by the hip flexors. If you anchor your feet under a bar or have someone hold them, you're making it even easier for your hip flexors to take over.

Straight-Leg Raises: Lying on your back and lifting your straight legs is one of the biggest culprits for lower back pain. The long lever created by your legs puts immense pressure on your lower back. To keep your spine from arching off the floor, your abs have to work incredibly hard. If they can't, your pelvis tilts forward, your back arches, and your hip flexors and lower back do all the lifting. You get zero ab benefit and a high risk of strain.

Russian Twists (With Poor Form): When done incorrectly, with a rounded lower back and jerky movements, Russian twists become a shearing force on your lumbar discs. People often focus on speed, swinging a weight from side to side, when the goal should be a slow, controlled rotation of the torso while the core stays braced and the lower back remains stable.

These exercises aren't just ineffective; they actively train your body to use the wrong movement pattern. You're reinforcing the very problem you're trying to solve, digging yourself deeper into a cycle of hip flexor dominance and back pain.

How to Fix It: The 3-Step Ab Activation Method

Getting your abs to fire correctly isn't complicated. It just requires you to slow down and focus on one key movement before you add any resistance or complex exercises. This three-step method will rebuild your mind-muscle connection and protect your back.

Step 1: Master the Posterior Pelvic Tilt

This is the foundation for every single ab exercise. It's the move that turns your abs on and your hip flexors off. Here’s how to do it:

1. Lie on your back with your knees bent and feet flat on the floor.
2. Notice the natural curve in your lower back. There should be a small space between your spine and the floor.
3. Now, gently engage your abs to tilt your hips backward, as if you're trying to press your lower back flat against the floor. The space should disappear.
4. Hold this flattened position for 5 seconds, focusing on feeling the contraction in your lower abs. Release and repeat for 10-15 reps.

This tiny movement is everything. Before you start any ab exercise, you must first perform a posterior pelvic tilt and hold it throughout the entire set. This locks your pelvis in place and forces your abs to be the prime mover.

Step 2: Modify Your Current Exercises

You don't have to abandon every exercise you know. You just need to modify them to make it harder for your hip flexors to cheat. The key is to shorten the lever.

• For Leg Raises: Instead of straight legs, bend your knees to 90 degrees. Lie on your back, perform the pelvic tilt to flatten your back, and then slowly lower your bent legs until your heels almost touch the floor. Your back must stay glued to the floor. If it starts to arch, you've gone too far.
• For Crunches: Place your feet up on a bench or chair with your knees and hips at a 90-degree angle. This position slackens the hip flexors, making it much harder for them to help. From here, perform a small crunch, lifting only your head and shoulder blades. The range of motion is tiny, but the contraction in your abs will be intense.

Step 3: Replace Bad Exercises with Better Ones

Some exercises are just not worth the risk. Swap them out for movements that build true core stability and are much more forgiving on your back.

• Dead Bug: This is the ultimate ab activation exercise. Lie on your back with your arms extended toward the ceiling and your knees bent at 90 degrees over your hips. Press your lower back into the floor (posterior pelvic tilt). Slowly lower your right arm and left leg toward the floor simultaneously, going only as low as you can while keeping your back flat. Return to the start and repeat on the other side. Aim for 3 sets of 10-12 reps per side.
• Plank: A classic for a reason. A proper plank teaches you to brace your entire core. Keep your body in a straight line from head to heels-no sagging hips or piking up. Squeeze your glutes and abs. Hold for 30-60 seconds for 3 sets.
• Bird-Dog: Start on all fours. Extend your right arm straight forward and your left leg straight back, keeping your hips and shoulders square to the floor. Your core must work to prevent your torso from rotating. Hold for 2-3 seconds and return to the start. Aim for 3 sets of 10 reps per side.

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What to Expect When You Make the Switch

When you start training your abs this way, a few things will happen. First, the exercises will feel much harder, and you'll probably have to do fewer reps. This is a good sign. It means your abs are finally doing the work instead of your hip flexors.

You should feel an immediate difference in your back. The straining sensation should disappear within your first 1-2 sessions. If you still feel your back, it means you're losing the posterior pelvic tilt during the exercise. Reduce the range of motion until you can maintain a flat back.

Within 2-4 weeks, this new movement pattern will start to become automatic. The mind-muscle connection to your abs will be stronger, and you'll be able to perform exercises with more control and without having to consciously think about the pelvic tilt every second. Your abs might feel sore in a way they never have before-a deep, satisfying burn rather than a sharp, superficial one.

Your progress won't be measured in how many hundreds of sit-ups you can do. It will be measured by your ability to hold a perfect plank for 60 seconds, perform a set of dead bugs without your back arching once, and finally feel your abs, not your back, working during every single rep.

Frequently Asked Questions

Is it bad if my back hurts during ab workouts?

Yes. Pain is your body's signal that something is wrong. While muscle fatigue or a "burn" in your abs is good, a sharp or aching pain in your lower back means you're likely putting stress on your spine and should stop the exercise immediately.

How do I know if my hip flexors are too tight?

Perform the Thomas Test. Sit on the edge of a sturdy table or bed, lie back, and pull both knees to your chest. Then, hold one knee to your chest and let the other leg hang freely. If that thigh can't drop parallel to the floor, your hip flexors are likely tight.

Should I stop doing sit-ups forever?

For most people, yes. There are far safer and more effective exercises for building your abs, like planks, dead bugs, and hollow body holds. Sit-ups offer a poor risk-to-reward ratio and reinforce bad movement patterns that can lead to back pain.

How many times a week should I train abs?

Your abs are a muscle group just like any other. They need time to recover. Training them with intention 2-3 times per week is plenty. Focus on quality reps and proper form, not on doing thousands of crunches every day.

Conclusion

Feeling your back during ab workouts is a sign that your technique is off, not that your back is weak. By focusing on the posterior pelvic tilt and choosing exercises that force your abs to do their job, you can eliminate back strain for good. Start with the basics, master the form, and build a truly strong and functional core.