Hanging Knee Raise

The hanging knee raise is a staple bodyweight ab exercise: hang from a pull-up bar and curl your knees up toward your chest using your abs, then lower them back down without swinging. It needs nothing but a bar, trains the lower rectus abdominis harder than most floor-based ab work, and builds the grip and shoulder stability that carry over to pull-ups and hanging leg raises. Because it's easy to cheat with momentum or let the hip flexors take over, it's also one of the most commonly misperformed ab exercises in the gym. This guide covers exactly how to do the hanging knee raise with strict form, the muscles it trains, how to program it, the mistakes that turn it into a hip-flexor exercise instead of an ab exercise, and the progressions worth adding as you get stronger.

What muscles does the hanging knee raise work?

The hanging knee raise trains the rectus abdominis through posterior pelvic tilt and hip flexion while your bodyweight hangs from a fixed bar. Diagnostic-ultrasound research on rectus abdominis segments shows leg-raise-style movements preferentially activate the lower fibers more than curl-up-style movements do, which is why the hanging knee raise is grouped with "lower ab" exercises even though the rectus abdominis is one continuous muscle. The hip flexors (iliopsoas and rectus femoris) do real work lifting the thighs, so if you let your lower back arch and your pelvis tip forward, the hip flexors take over and the abs do less — tilting your pelvis toward your ribs before you raise your knees is what keeps the tension on the abs. Your forearms, shoulders and lats also work hard isometrically just to keep you hanging still on the bar.

How grip and angle change muscle activation

Ultrasound and EMG research on rectus abdominis segments shows leg-raise-pattern exercises like the hanging knee raise bias the lower fibers of the rectus abdominis more than trunk-curl exercises like the crunch, which bias the upper fibers instead. These are relative, approximate findings from segment-thickness and normalized EMG studies — useful for choosing exercises, not exact numbers for any one lifter.

• Leg-raise pattern (hanging knee raise): Shows the largest relative increase in muscle-thickness change in the lowest rectus abdominis segment, indicating preferential lower-fiber activation.
• Curl-up pattern (crunch, sit-up): Produces a significantly larger upper-to-lower EMG ratio, meaning the upper rectus abdominis works relatively harder than in a leg raise.
• Neutral pelvis vs. arched lower back: A posterior pelvic tilt keeps the abs under tension through the whole rep; an arched, anteriorly tilted pelvis shifts the work onto the hip flexors instead.

Based on EMG research. [1]

How do you do the hanging knee raise?

To do the Hanging Knee Raise: grip a pull-up bar slightly wider than shoulder-width with a pronated (overhand) grip and hang with your arms fully extended and feet off the floor; brace your core and pull your shoulder blades down and back to stop yourself from swinging — this is your still, controlled starting position; tilt the top of your pelvis up toward your ribs (a slight posterior pelvic tilt) and squeeze your glutes to switch your lower abs on before you move; exhale and curl your knees up toward your chest, leading with your lower abs rather than kicking your legs or swinging your torso.

1. Grip a pull-up bar slightly wider than shoulder-width with a pronated (overhand) grip and hang with your arms fully extended and feet off the floor.
2. Brace your core and pull your shoulder blades down and back to stop yourself from swinging — this is your still, controlled starting position.
3. Tilt the top of your pelvis up toward your ribs (a slight posterior pelvic tilt) and squeeze your glutes to switch your lower abs on before you move.
4. Exhale and curl your knees up toward your chest, leading with your lower abs rather than kicking your legs or swinging your torso.
5. Pause briefly once your thighs pass parallel to the floor or your knees reach chest height, keeping the movement controlled.
6. Inhale and lower your legs back to the hang under control, stopping just short of a dead swing before starting the next rep.

What are the key hanging knee raise form cues?

Pelvic tilt

Tilt your hips up toward your ribs before you raise your knees — this switches on the lower abs instead of the hip flexors.

No swing

Keep your torso still and let your knees do the traveling. If your body is swinging, you're using momentum instead of your abs.

Grip and shoulders

Keep your shoulder blades pulled down and back rather than letting your shoulders shrug up toward your ears for the whole set.

Exhale on the lift

Breathe out as your knees come up — holding your breath makes it harder to brace your abs through the rep.

Controlled descent

Lower your legs with the same control you used to raise them; dropping fast turns the negative into a free rest instead of extra work.

Breathing & tempo: Exhale as you curl your knees up, inhale as you lower back to the hang. A controlled 2-1-2 tempo (2s up, 1s pause, 2s down) keeps tension on the abs and makes it far harder to cheat with momentum than a fast, bouncy rep.

How should you warm up for the hanging knee raise?

Prime your grip and shoulders before working sets with 20–30 seconds of a passive dead hang, then 5–10 slow, sub-maximal knee raises to groove the posterior pelvic tilt without fatigue. A few reps of dead bugs or lying knee tucks beforehand also help you feel the same pelvic-tilt pattern with your feet on the ground.

What are the most common hanging knee raise mistakes?

• Swinging the body to generate momentum — Slow the tempo down, keep your torso still, and stop the set once you can no longer raise your knees without swinging.
• Letting the lower back arch (anterior pelvic tilt) — Actively tilt your pelvis up toward your ribs and squeeze your glutes before every rep so your abs, not your hip flexors, initiate the movement.
• Only raising the knees a few inches — Aim for thighs at least parallel to the floor — a short partial range trains mostly hip flexion instead of the intended abdominal curl.
• Shrugging the shoulders up to the ears — Pull your shoulder blades down and back and keep them there for the whole set to protect the shoulders and keep the hang stable.
• Letting grip fatigue end the set before the abs are worked — Use lifting straps or a captain's chair (forearm-supported) variation once grip becomes the limiting factor rather than the abs.

Why does the hanging knee raise hurt — and how do you fix it?

Most hanging knee raise discomfort comes from compensating for weak abs or a tired grip, not from the exercise itself. See a professional if pain is sharp, radiates, or doesn't improve once your form is corrected.

How many sets and reps should you do?

Choose your sets and reps by goal: heavier and fewer reps for strength, moderate for muscle size, lighter and higher for endurance.

RPE / RIR: Train most sets at RPE 7–8 (2–3 reps left in the tank) so form stays strict through the last rep. Stop a set the moment you have to swing to finish a rep — grinding out "cheat" reps trains your hip flexors and momentum more than your abs.

Once you can hit 12–15 strict reps with a full range of motion, progress the exercise rather than just adding more reps — slow the tempo, add a pause at the top, add light ankle weights, or move toward straightening the legs into a hanging leg raise. The rectus abdominis recovers quickly, so most lifters can train hanging knee raises 2–4 times a week without excess soreness.

How often should you hanging knee raise and where does it fit?

Train the Hanging Knee Raise 2–4 sessions per week, placing it late in the session, after your main pulling or pressing work — pre-fatiguing the core and hip flexors can hurt performance on bigger lifts..

• Frequency: 2–4 sessions per week
• Best split days: End of a pull day (Push/Pull/Legs), Core finisher on any training day, Dedicated core/ab session
• Where to place it: Late in the session, after your main pulling or pressing work — pre-fatiguing the core and hip flexors can hurt performance on bigger lifts.

Pair it opposite an anti-extension exercise like the plank or dead bug across the week so you're training the core through more than one pattern.

How do you progress the hanging knee raise?

Add reps up to about 12–15 with a full, controlled range and zero swing before adding external load or moving to a straight-leg variation. Strengthening your grip and overhead shoulder position with regular dead hangs also removes two common bottlenecks that stop the abs from ever getting properly fatigued.

What's the right range of motion?

A full rep runs from a dead hang with straight legs to at least thighs-parallel-to-the-floor, ideally knees toward the chest. Stopping short (only a few inches of hip flexion) shifts the work toward the hip flexors and away from the abdominal curl the exercise is meant to train, so chase range before you chase reps.

What are the benefits of the hanging knee raise?

• Builds the lower rectus abdominis harder than most floor-based ab exercises, according to segment-activation research
• Trains grip strength and shoulder stability as a free carryover to pull-ups and hanging work
• Needs only a pull-up bar, making it easy to program anywhere
• A natural stepping stone toward harder hanging core work like the hanging leg raise and toes-to-bar

Who should do it: Lifters who already have pain-free overhead shoulder mobility and want to build core strength beyond the floor, calisthenics and pull-up trainees looking to build toward toes-to-bar, and anyone whose ab training has plateaued on crunches and wants a harder bodyweight progression.

Is the hanging knee raise safe?

The hanging knee raise is safe for most healthy lifters with pain-free overhead shoulder mobility, a controlled tempo and a posterior pelvic tilt — most discomfort comes from swinging, an arched lower back, or grip fatigue rather than the exercise itself.

Shoulder impingement or limited overhead mobility

Build up tolerance with short, passive dead hangs first, and consider a captain's chair (forearm-supported) knee raise, which removes the overhead hang position entirely.

A history of hip flexor tightness or discomfort

Focus on the posterior pelvic tilt cue and stop the range where you first feel the lower back want to arch, rather than forcing extra height.

Weak or fatigued grip

Use lifting straps or switch to a captain's chair variation so grip failure doesn't cut a set short before the abs are properly worked.

Spotting: No spotter is needed — the hanging knee raise is a self-paced bodyweight movement. If your grip gives out mid-set, simply drop down to the floor under control.

How do grip and stance change the hanging knee raise?

• Pronated (overhand) grip: The standard grip — stable and shoulder-friendly for most lifters.
• Neutral grip (parallel handles): Gentler on the wrists and shoulders if a straight bar bothers you; common on power towers and dip stations.
• Lifting straps: Removes grip as the limiting factor so a set ends when your abs fatigue, not your forearms.

Hanging Knee Raise variations

How does the hanging knee raise compare?

Hanging Knee Raise vs. Hanging Leg Raise

The hanging knee raise bends the knees, shortening the lever arm and making it accessible earlier in a lifter's training. The hanging leg raise keeps the legs straight, which increases the torque on the abs and hip flexors substantially — progress to it once knee raises feel easy for 12–15 strict reps.

Hanging Knee Raise vs. Captain's Chair Knee Raise

The hanging knee raise adds a genuine grip and shoulder-stability demand on top of the ab work, which the forearm-supported captain's chair removes. Choose the captain's chair when grip or shoulder position is the limiting factor rather than the abs, and the hanging version once your grip can keep up.

Hanging Knee Raise vs. Crunch

Segment-activation research suggests the hanging knee raise biases the lower rectus abdominis more than the trunk-curl pattern of a crunch, which biases the upper fibers. The crunch needs no equipment and is easier to learn; the hanging knee raise adds range, load and a grip challenge once the floor version stops being enough.

Hanging Knee Raise alternatives

How many calories does the hanging knee raise burn?

Calories depend on your bodyweight and how hard you train. Resistance training has a MET value of about 4. Enter your bodyweight and minutes to estimate the burn (calories = MET × kg × 3.5 ÷ 200 × minutes).

Hanging Knee Raise strength standards

The hanging knee raise is a bodyweight core exercise, not a loaded lift, so use a max-strict-reps benchmark instead of a bodyweight-multiple table. These bands are drawn from general calisthenics norms rather than a single peer-reviewed study — treat them as motivating targets, not hard rules.

By age: Core endurance holds up relatively well with age compared with maximal-strength lifts; grip endurance tends to be the earlier limiter, so straps or a captain's chair keep the exercise accessible well past your 40s and 50s.

What counts as a good rep?

A full rep starts from a dead hang with straight legs and a still torso, curls the knees up to at least thighs-parallel using a posterior pelvic tilt rather than a leg swing, and returns under control to the starting hang without the torso swinging forward or back.

References

1. Gomirato AP, Grenier SG. Diagnostic Ultrasound Shows Preferential Activation of Rectus Abdominis Segments with Exercises Targeting Upper Versus Lower Segments. International Journal of Exercise Science / PMC, 2023
2. Marchetti PH, Kohn AF, Duarte M. Selective Activation of the Rectus Abdominis Muscle During Low-Intensity and Fatiguing Tasks. Journal of Sports Science & Medicine / PMC, 2011
3. Implementing Core Training Concepts into Strength Training for Sport. National Strength and Conditioning Association (NSCA)
4. For a Great Core Workout, Give Hanging Knee Raises a Try. Healthline (medically reviewed)
5. How to Do Hanging Knee Raise: Muscles Worked & Proper Form. StrengthLog
6. Lift Up Your Ab Workouts with the Hanging Knee Raise. BarBend
7. Hanging Leg-Hip Raise. ExRx.net