Lift Up Your Ab Workouts with the Hanging Knee Raise

This iconic core movement can help craft the set of abs you've always wanted.

Training the midsection often gets compartmentalized into either functional core work or direct abdominal work. While there isn’t anything inherently wrong with either mode of training, and goal specificity should be the driving factor behind your exercise selection – in some cases there are exercises that can bridge the gap between these two camps.

The hanging knee raise is a great hybrid, serving to integrate core and direct abdominal training simultaneously, and we’re going to dive into everything there is to know about it and more. 

How to Perform the Hanging Knee Raise 

The hanging knee raise can be performed using any pull-up bar. The only prerequisite is the grip strength to hang from a bar long enough to perform the exercise and to have pain-free overhead shoulder mobility.

Step 1 – Get Your Grip

Credit: Mike Dewar

Stand directly underneath the bar and raise your hands comfortably overhead. Usually, this places the grip about shoulder-width apart or slightly wider.

Step 2 – Set and Hang

Once you have your grip, allow a few moments to pass in a dead-hang to minimize any swaying from the initial momentum of grabbing the bar. From here, set the shoulder blades back and down, squeeze the legs together, and perform a body hollow. Brace the core the same way you would when preparing for a barbell exercise.

Step 3 – Flex the Abs

Credit: Mike Dewar

Each repetition of the hanging knee raise should be performed such that the final squeeze of the abs is beyond 90 degrees of hip flexion. In order to target the abdominals, the spine must be flexed – think of engaging the abdominals to pull the knees towards your chest with a similar sensation of performing a sit-up.

Step 4 – The Reset

Credit: Mike Dewar

Allow your legs to return to the starting position under control, keeping tension engaged throughout the body the entire time. The less you release core tension, the less swaying or loss of position you will experience between repetitions.

Benefits of the Hanging Knee Raise

The hanging knee raise is a great way to target the abdominals for direct six-pack hypertrophy training, but it also helps develop core strength and overhead capabilities for transfer into many other exercises.

Six-pack Hypertrophy

While a long-term sustainable lifestyle with an emphasis on reducing excess body fat is the major tenet of achieving visible abs, you’ll still want to give the rectus abdominis a bit of direct training to make them really pop. The rectus abdominis’ action is to flex the spine and the hanging knee raise accomplishes just that.

Core Strength

The hanging knee raise improves full body core strength because of the tendency for the body to sway during each repetition. The ability to neutralize any body sway and to allow the abdominal muscles to flex the spine requires some serious core strength – the muscles of the shoulder, hip, and spine are all targeted to freeze the body in as consistent a position as possible.

Overhead Capabilities

The mobility and stability required to accomplish a hanging knee raise compliments and maintains the shoulder’s overhead capabilities because gravity only works in one way – straight down. As gravity continuously pulls the shoulder into the full overhead position, it also serves as constant reinforcement of full overhead shoulder mobility.

Use it or lose it, and using it while developing the core is a great incentive.

Muscles Worked by the Hanging Knee Raise

Unsurprisingly, the hanging knee raise is almost exclusively a core exercise. However, one of the main technique considerations involving its performance is also directly related to another big muscle that is involved in the execution.

Rectus Abdominis

The rectus abdominis muscle, also known as the ever-desired abs, is the primary mover in the exercise. The abdominals connect the ribcage to the pelvis and facilitate flexion, twisting, and general function of the torso. In the knee raise, they’re working hard to pull on the pelvis as the legs elevate in space.

Hip Flexors

Engagement from the hip flexors is considered a fault in the performance of the hanging knee raise. That said, it does merit a mention — if you’re performing sets of the knee raise and only feel a pinch or pull in the crease of the hip, it’s likely because the hip flexors are performing the work that should be taken on by the lower abs. 

Who Should Do the Hanging Knee Raise

The hanging knee raise has benefits for physique athletes, strength athletes, and the average gym-goer alike.

Physique Athletes

Physique athletes are in a constant search for complimentary exercises to pump up each body part from slightly different angles. The hanging knee raise serves as an excellent compliment to the standard crunch in order to develop the six-pack but also allows for a subtly different challenge.

Strength Athletes

Strength athletes would benefit from the hanging knee raise for many reasons – the first of which being reinforcement of proper bracing technique. As a major contributor to the efficacy of the hanging knee raise is the ability to eliminate momentum, a strength athlete would see excellent carryover between this exercise and their typical core brace sequence during their heavy lifting.

Average Gymgoers

The average gymgoer is often pursuing many goals at once. Improvements in overhead mobility and stability, carryover into grip strength and body awareness, and the obvious benefits for the core while performing the hanging knee raise check a lot of boxes.

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However, from a pure enjoyment standpoint, they can also serve as a launching pad to perform many calisthenic exercises like the weighted pull-up in the future.

Hanging Knee Raise Sets, Reps, and Programming Recommendations

Hanging knee raises are an effective way to functionally train the core while also directly targeting the abdominals, but, depending on the fitness level of the trainee, recommendations may vary.

Recommendations for Newer Trainees

For newer trainees, strength, skill, or muscular endurance may all be limitations in performing the hanging knee raise. In any of these situations it may be beneficial to prioritize the hanging knee raise towards the beginning of the workout or place it on its own day with other core exercises.

Begin with 2 – 3 sets of 6 – 8 repetitions, focusing on perfect technique each workout until you’re able to add more volume.

Recommendations for Intermediate Trainees

For intermediate trainees who have acquired the skill and base level of strength to routinely perform the hanging knee raise, targeting a muscle building set and repetition scheme would be the most beneficial.

Perform three or four sets of 10 – 15 repetitions several times per week.

Recommendations for Advanced Trainees

It can be quite difficult to add resistance to the hanging knee raise without forcing excessive momentum or recruitment of the hip flexor muscles – thus it would be recommended that advanced trainees utilize higher repetition sets.

Perform three to four sets of 15 – 20 repetitions several times per week, or attempt very strict reps with a light dumbbell held between the ankles. 

Hanging Knee Raise Variations

Variations of the hanging knee raise can be performed to either serve as part of a circuit or cluster set or help build towards the hanging knee raise itself.

Roman Chair Knee Raise

The roman chair knee raise provides back and arm support for a trainee who may not be able to perform a hanging knee raise quite yet. The back rest prevents undue body sway and loss of proper positioning while the arm rests remove the grip strength requirement – allowing complete focus on abdominal contractions.

Hanging Straight-leg Raise

The hanging straight-leg raise increases the challenge experienced from a hanging knee raise by extending the lever acting against the abdominals. The longer the distance your feet are away from your core muscles, the harder they have to work in order to flex the spine on each repetition.

Hanging Knee Raise Alternatives

The hanging knee raise is meant to target the abdominals while also integrating proper core engagement. Alternatives to the hanging knee raise that also accomplish these goals are the lying knee raise, lying leg raise, and gymnastic ring knee raises.

Lying Knee Raise

While lying flat on the ground, flatten the small of the back into the floor while placing your hands palm-down on either side of your body. Draw your knees towards your chest while contracting the abdominals.

Lying Leg Raise

From a supine position, flatten the small of the back into the floor while placing your hands palms down on either side of your body. Raise your straightened legs towards the ceiling until your body reaches a 90 degree angle with the legs perpendicular to the floor.

Gymnastic Ring Knee Raise

While hanging from two independent gymnastic rings, perform the hanging knee raise. This will place an increased emphasis on core and shoulder stability in order to neutralize movement from the two individual rings and eliminate any loss of position.

Pulling It All Together

The hanging knee raise is a low barrier to entry exercise with a great return on investment. Not only training the abdominal muscles, but also integrating core strength – trainees from a wide variety of skill levels and goals can use this exercise to great benefit. With a well-rounded series of progressions and alternatives to accommodate anyone, the hanging knee raise can be a staple in many excellent training programs for the long haul.

Frequently Asked Questions 

If you’re still wondering a thing or two about the leg raise, hang around for a minute longer and check out our answers to some of the most common questions about the movement. 

Are hanging knee raises safe to perform?

Yes! Each exercise has certain requirements to be as safe and effective as possible, and the hanging knee raise is no different. If you can safely put your arms over your head and hang without any pain, you can perform the hanging knee raise.

How often should I train the hanging knee raise?

This depends on the training age of the individual and the amount of other direct or indirect core exercises they are performing. Someone with a low amount of free weight exercises in their program might be able to train the hanging knee raise many times per week, whereas, someone with many barbell exercises or other direct core work might want to train them less frequently.

How do I add weight to the hanging knee raise?

This one is tricky. To intensify many exercises the go-to move is usually increasing weight, but with the hanging knee raise that could alter the muscles involved. To properly flex the abdominals and not lift the weight with the hip flexors becomes very difficult, so our recommendation would be to intensify the exercise through higher repetitions or extending the knees into a hanging leg raise.

Featured Image: Mark Aliaksandr / Shutterstock