Hanging Knee Raises

What the hanging knee raise actually trains

A hanging knee raise is an abdominal exercise performed hanging from a bar, where you raise your bent knees towards your chest and curl your pelvis at the top before lowering under control.

The hip flexors, psoas major, iliacus and rectus femoris, lift the thighs. The rectus abdominis and obliques stabilise throughout and shorten properly at the top when the pelvis tilts backwards. The lats, forearms and shoulders hold you on the bar.

Lifting the knees from hanging to hip height is hip flexion. Your abdominals are working, but their job in that phase is to stop the pelvis tipping forwards and the lower back arching, which is stabilisation. The rectus abdominis only shortens meaningfully once the pelvis begins to curl and the hips travel up towards the ribs.

This is why the standard advice to raise the knees higher is right for the wrong reason. The value is not in the height, it is in the pelvic curl. A rep that stops with the thighs horizontal and no curl is a hip flexor rep with an abdominal brace attached.

Escamilla and colleagues found leg raising patterns produce high rectus abdominis and oblique activity alongside substantial hip flexor involvement, which is exactly this picture measured properly.

Compared with the straight leg version, bending the knees shortens the lever. That is the entire difference. It is the same exercise at a load you can control, which usually means better reps and a real pelvic curl.

The limiting factor for many people is not the abdominals but the hands. If your grip gives out at rep eight, you are training your forearms. Straps fix that, and so does a captain's chair.

Setting up and executing

Take an overhand grip on a bar at roughly shoulder width and hang with the arms straight and the feet clear of the floor.

Pull the shoulders down away from your ears. A fully passive hang is uncomfortable and makes the body harder to control, so keep some tension in the lats.

Let the body come to a complete stop before starting. This is the step almost everyone skips and it decides the quality of the whole set.

Brace the abdominals, squeeze the knees together, and raise them towards the chest. Once the thighs pass horizontal, curl the pelvis backwards so the hips lift.

Pause for a beat at the top.

Lower the knees over about three seconds, then let the hang settle again before the next repetition.

The mistakes that cost you the most

Swinging through the set is the fault that ruins this exercise. Once the body is moving like a pendulum, the swing lifts the legs and the abdominals become passengers. Coming to a full stop between reps feels fussy and cuts your rep count, and it is the single change that makes the exercise work.

Stopping at hip height leaves out the abdominal portion entirely. Pallarés and colleagues found full range training produced better strength and hypertrophy outcomes than partial range work, and the range being cut here is precisely the part that trains the abdominals.

Dropping the knees discards the lowering phase. Schoenfeld and colleagues found eccentric and concentric training produce broadly similar hypertrophy when other variables are matched, which is a reason to treat the descent as half the exercise rather than as a rest.

Grip failing first is a solvable problem that people treat as a verdict. Use straps, or move to a captain's chair, rather than accepting sets that end at your forearms.

And hanging with shrugged shoulders is uncomfortable and unstable, particularly as the load rises. Pull the shoulders down and stay actively hanging.

Sets, reps and rest by goal

Treat this as a strength exercise with a moderate rep range rather than an endurance drill.

For muscle gain, four sets of eight to fifteen with ninety seconds rest. For strength, three sets of six to ten with two minutes, adding load between the feet. In a fat loss phase, three sets of twelve to twenty with a minute.

Adding load is what almost nobody does and what almost everybody needs. Abdominals respond to load and progression like any other muscle. A five kilogram dumbbell squeezed between the feet turns an easy set of fifteen back into a hard set of eight.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy. Four to eight hard sets a week across two sessions is a reasonable target for direct abdominal work.

Refalo and colleagues found stopping a rep or two short of failure produces comparable growth to going all the way. That is helpful here, because the reps beyond that point are where the swing arrives and the pelvic curl disappears.

Where it fits in your split

At the end of a session, ideally one where you are already at a bar.

On push, pull and legs it belongs at the end of pull day. On an upper duo split it follows the pulling work. On a bro split it fits on back or arms day. On upper and lower plus full body it goes last in either upper session. On a bodyweight programme it is the main abdominal movement on pull day.

Do not use it before heavy squatting or deadlifting. Trunk fatigue going into a maximal lift is a poor exchange, and tired hip flexors do not help either.

Two sessions a week is enough. The abdominals recover like other muscles and do not need daily attention.

If you are choosing one abdominal exercise, this or the captain's chair version is a strong pick, since it covers the pelvic curl that crunches never reach.

Variations worth knowing

The hanging leg raise straightens the legs, lengthening the lever substantially. It is the natural progression, not a different exercise.

The captain's chair knee raise is the same movement with forearm support, which removes the grip limit and lets the abdominals decide when the set ends.

The weighted hanging knee raise, with a dumbbell between the feet, is how the movement keeps producing results after fifteen clean reps become easy.

Toes to bar raises the feet all the way up to the bar, which is a considerably longer range and a genuine skill worth practising if you enjoy it.

The hanging oblique knee raise draws the knees to one side, adding a direct demand on the external and internal oblique.

And the lying knee tuck is the floor version, useful if you cannot yet hang comfortably for a full set.

What the evidence says

Escamilla and colleagues compared common and commercial abdominal exercises and found hanging and supported leg raise patterns among the higher options for rectus abdominis and oblique activity, which supports the exercise as a primary abdominal movement.

Escamilla and colleagues also examined traditional and non traditional abdominal exercises and reported substantial hip flexor involvement in leg raising, confirming that this is a shared movement rather than an isolation exercise for the abdominals.

McGill's review of core training makes the case that trunk training has genuine but limited benefits, and that claims about preventing back injury run ahead of the evidence. This builds abdominal muscle; treat that as the reason to do it.

Pallarés and colleagues found full range training beat partial range work for strength and hypertrophy, which is the argument for curling the pelvis at the top rather than stopping with the thighs horizontal.

Schoenfeld and colleagues found eccentric and concentric actions produce broadly comparable hypertrophy when matched, which supports controlling the descent rather than letting the knees drop.

Schoenfeld and colleagues also found a dose response between weekly hard sets and hypertrophy, supporting a small number of hard, progressively loaded sets.

Refalo and colleagues found training close to failure is not required for growth, so ending the set when the swing appears costs nothing worth having.

Common questions

Knees or straight legs?

Knees, until you can complete fifteen controlled reps with a genuine pelvic curl and no swing. Straight legs only lengthen the lever, and most people who insist on them are doing worse reps than they would with knees bent.

How do I stop swinging?

Come to a complete stop before every rep, and start from a dead hang rather than immediately after the previous descent. If that is impossible at your current strength, reduce the range or use a captain's chair, where the back pad does the stabilising for you.

Is this the same as a captain's chair leg raise?

Almost. Same movement, same muscles, same pelvic curl. Hanging adds a grip and lat demand and lets the body swing; the chair removes both. If your grip fails first, use the chair.

My hip flexors do most of the work. Is that wrong?

No. Raising the thighs is hip flexion and the hip flexors are the correct muscles for it. The abdominal contribution comes from the pelvic curl at the top and from holding the lower back flat throughout, so add the curl and stop trying to eliminate the rest.

How do I progress once fifteen reps are easy?

Slow the descent to four seconds, then hold a dumbbell between your feet, then straighten the legs. Adding more reps past twenty builds endurance rather than muscle, and the abdominals grow from load in the same way as everything else.