You've seen them. That person at the gym hanging from the pull-up bar, swinging their legs around like a frantic pendulum. They think they’re carving out a six-pack. Honestly? They’re mostly just wearing out their shoulder sockets and irritating their hip flexors. If you want a core that actually functions—and looks—the way you intend, you have to master the twisting hanging knee raise. It’s not just about lifting your legs. It's about a specific, rhythmic rotation that forces the obliques to actually do their job instead of just sitting there while your hip flexors take the lead.
Stop swinging. Seriously.
The Anatomy of a Real Twisting Hanging Knee Raise
Most people treat the core like a single sheet of muscle. It isn't. You have the rectus abdominis—the "six-pack"—but then you have the internal and external obliques. These are your body's natural corset. When you perform a standard hanging knee raise, you're hitting the front. When you add the twist, you're engaging the internal obliques on one side and the external obliques on the other to create torque.
Dr. Stuart McGill, a leading expert in spine biomechanics, often talks about "proximal stiffness for distal mobility." Basically, your core needs to be a rock so your limbs can move. In the twisting hanging knee raise, we are challenging that stiffness while introducing controlled rotation. If you just flop your knees side to side, you’re missing the point. The movement should start at the pelvis. You aren't just moving your knees; you are tilting your entire pelvic bowl toward your armpit.
It’s hard. It should be.
Why Your Grip is Killing Your Abs
Here is a cold truth: your abs are probably stronger than your hands. Most people drop off the bar because their forearms are screaming, not because their obliques are tired. This is the "Grip Ceiling." If you can't hang for 60 seconds, you'll never get the volume needed for real growth.
- Try using gym chalk to keep your hands dry.
- Don't over-grip the bar; hook it with your fingers rather than death-gripping with your palms.
- If you're really struggling, use "captain’s chair" stations or elbow straps, though you'll lose some of the lat stabilization benefits.
How to Actually Do It (The No-BS Way)
First, get a dead hang. Your shoulders shouldn't be touching your ears. Pull your shoulder blades down and back—this is called "packing" the shoulders. It engages the lats, which provides a stable platform for your spine.
Now, instead of just pulling your knees up, imagine there is a flashlight on your belly button. You want to point that flashlight toward your right shoulder as you lift. Squeeze. Hold it for a micro-second at the top. Lower slowly. If you drop your legs fast, gravity does the work. Gravity doesn't give you abs. Resistance does.
Then, go to the left.
You’ll feel a pinch in your side. That’s the obliques firing. If you feel it mostly in the front of your thighs, you’re using too much psoas and iliacus (your hip flexors). To fix this, try to "round" your lower back as you lift. Think about bringing your pubic bone toward your sternum.
Common Fails That Make You Look Silly
- The Swing: If you look like you’re on a playground swing set, stop. Use a wall behind you if you have to, or have a partner put their hand behind your lower back to stop the momentum.
- The Half-Rep: Bringing your knees to waist height is a warm-up. Bringing your knees to your chest is a workout.
- Breath Holding: You need intra-abdominal pressure. Exhale hard as you twist and lift. Inhale on the way down.
The Science of the "Twist"
A study published in the Journal of Orthopaedic & Sports Physical Therapy looked at various abdominal exercises using EMG (electromyography) to see which muscles fired the most. Hanging leg raises consistently rank near the top for both the lower rectus abdominis and the obliques. By adding the rotation, you significantly increase the demand on the obliquus externus abdominis.
This matters because your obliques are responsible for rotational power. Whether you’re swinging a golf club, throwing a punch, or just trying not to throw your back out while carrying groceries, you need that lateral stability. The twisting hanging knee raise is one of the few "open chain" exercises that allows for a massive range of motion under tension.
Variations for the Brave
Once the basic version feels "easy"—and I use that term loosely because it should never feel easy—you can level up.
The Straight-Leg Twist: Instead of bending your knees, keep your legs straight. This increases the lever length, making the weight of your legs feel much heavier. It puts a massive strain on the core. Warning: if you have lower back issues (like a herniated disc), stick to the knee version. The long lever can put a lot of shear force on the lumbar spine.
The "Around the World": Instead of going left-center-right, you move in a continuous circle. You bring the knees up to the right, sweep them across the chest to the left, and lower them. Then reverse. It’s brutal.
Weighted Twists: Hold a small 2kg or 5kg dumbbell between your feet. It doesn't take much. Even a tiny bit of extra weight at the end of your legs feels like a ton of bricks.
Let’s Talk About Spinal Health
There is a debate in the fitness world. Some people, following the "Mcgill Big 3" philosophy, believe you should never rotate the spine under load. They prefer "anti-rotation" exercises like the Pallof Press. Others believe the spine is meant to move and should be strengthened in all planes of motion.
Who is right? Kinda both.
👉 See also: How to Master a Quadriceps Workout at Home Without Trash Equipment
If you have an active back injury, twisting while hanging is probably a bad idea. But for a healthy athlete, training the spine to handle rotation is a safeguard against future injury. The key is control. Jerky, uncontrolled twisting is how you end up in a physical therapist’s office. Smooth, muscularly-driven twisting is how you get a bulletproof back.
Programming for Results
Don't do these every day. Your abs are muscles like any other; they need recovery.
- For Beginners: 3 sets of 8-10 reps (total). Focus on zero swing.
- For Intermediate: 4 sets of 12-16 reps. Add a 2-second pause at the top of every twist.
- For Advanced: 3 sets to failure with straight legs.
You should probably do these at the beginning of your workout or the very end. If you do them right before heavy squats or deadlifts, your core might be too fatigued to stabilize your spine during the big lifts. Be smart.
Honestly, the biggest mistake is just not doing them. People gravitate toward floor crunches because they’re easy. You can do 100 crunches while thinking about what you want for dinner. You cannot do a single proper twisting hanging knee raise without total concentration. That’s why it works.
Actionable Steps to Master the Move
Start by testing your hang time. If you can’t hang for at least 30 seconds, spend two weeks just doing "active hangs" where you pull your shoulders down and hold. This builds the foundational lat and grip strength you'll need.
Once your grip is set, practice the "Posterior Pelvic Tilt" on the ground. Lay on your back and try to flatten the small of your back against the floor. That's the feeling you need while hanging. If your back is arched while you're on the bar, you're just using your hip flexors.
When you finally move to the bar, don't worry about how high your knees go at first. Focus on the rotation. Turn your hips, then lift. If you do ten reps and your obliques feel like they're cramping, you've nailed it.
The next time you're at the gym, skip the "ab coaster" machine. Find a bar. Hang. Twist. Actually feel the muscles working for once. You'll notice the difference in your lifts—and your reflection—sooner than you think.
Go get on the bar. Focus on the pelvic tilt. Control the descent. Stop when your form breaks, not when you're tired. Real core strength is built in those last two reps where you refuse to let your body swing.