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Bent Knee Lying Twist is a abs-focused exercise built around a rotation pattern and performed with bodyweight. The muscular job here is to flex the spine and brace the trunk, and that translates directly into trunk stability and force transfer. What separates this variation from other abs work is that it is performed from a lying position and emphasising rotational movement through the torso — a detail that changes which fibres take the load and how much stability the movement demands. The 'Bent Knee Lying Twist' element in the name is the part that matters technically — it defines the exact position and path this version uses, and swapping it changes the training effect. Support comes from the obliques and hip flexors; the obliques in particular help rotate and side-bend the torso, which is why fatigue there often shows up before the abs is fully worked. Training this with bodyweight needs no equipment at all and can be done virtually anywhere, though it is harder to load progressively once you outgrow it. Programme it alongside your other abs work rather than as a standalone. The pattern is accessible enough to learn in a single session, which makes it a sound entry point before progressing to heavier or more complex variations.
The Bent Knee Lying Twist is primarily a abdominals exercise, but it is never only the abdominals doing the work.
The general rule for the Bent Knee Lying Twist is simple: exhale through the rotation, inhale on the return. Keep the breath flowing continuously — there is no need to hold pressure in this pattern. Getting this right stabilises your trunk and keeps blood pressure in a sensible range.
Perform the movement slowly with a light load until the pattern feels automatic. Stay at this level until every Bent Knee Lying Twist rep looks the same as the first.
Add a one- to two-second pause at the hardest position of each repetition. Alternate harder and easier Bent Knee Lying Twist sessions rather than pushing every one.
Slow the lowering phase to three or four seconds to accumulate tension without adding weight. At this level the Bent Knee Lying Twist is best programmed after your heaviest abs work, not before it.
The Bent Knee Lying Twist suits most healthy trainees, but it is not appropriate for everyone.
This is general educational information, not medical advice. If you are managing an injury or medical condition, check with a qualified professional before adding this exercise to your programme.
It primarily trains the abdominals, with the obliques and hip flexors assisting. The pattern is classified as rotation, so the obliques, deep abdominals and hip stabilisers share the workload.
Yes. It is rated beginner-level, and the pattern can usually be learned in a single session with light resistance.
A practical starting point is 3 sets of 6-8, resting 2-3 min between sets, roughly 2x per week. Adjust from there based on how you recover.
You need bodyweight. This needs no equipment at all and can be done virtually anywhere, though it is harder to load progressively once you outgrow it.
As a general rule, exhale through the rotation, inhale on the return. Avoid holding your breath for the entire set.
Forcing range from the lower back instead of the thoracic spine. The simplest correction is to rotate from the ribcage and keep the hips relatively quiet.
Good substitutes that train the same abs pattern include Barbell Seated Twist On Exercise Ball, Ab Wheel Left Out, and Assault Airbike Fast Speed. Pick whichever matches the equipment you have available.
Changing the angle changes which fibres of the abdominals take the most tension, so it complements rather than duplicates your other abs work.
The Bent Knee Lying Twist fits into that picture as a beginner option using bodyweight, leaning on the obliques and hip flexors alongside the abs.
The core is far more than a visible six-pack. It is a coordinated group of muscles that includes the rectus abdominis — the long muscle that creates the six-pack appearance and flexes the spine — the internal and external obliques on the sides that rotate and bend the torso, and the deep transverse abdominis that wraps around the midsection like a belt to stabilise the spine and protect the lower back.
Effective core training works all of these functions rather than relying on endless crunches. Flexion exercises such as crunches, sit-ups, and hanging leg raises target the rectus abdominis and are excellent for building visible abdominal muscle. Rotational and anti-rotation work such as Russian twists and cable woodchops develops the obliques and the ability to resist twisting forces. Bracing and isometric holds like the plank and its variations train the deep stabilisers that give you a strong, protected midsection during heavy lifts and everyday movement.
Because the core is involved in stabilising almost every compound lift, it already gets significant indirect work from squats, deadlifts, and overhead presses. Direct ab training a few times per week, with a mix of weighted flexion work in the 8 to 15 range and longer isometric holds, is enough for most people to build a strong, defined midsection. Adding resistance to ab exercises over time is just as important as it is for any other muscle.
The most important thing to understand about abs is that visibility is primarily a function of body-fat level, not the number of crunches you do. You can build thick, strong abdominal muscles, but they will only show when body fat is low enough, which is achieved through nutrition and overall training rather than spot reduction. There is no exercise that burns fat from the stomach specifically. Focus ab training on building and strengthening the muscles, and rely on a sensible diet and full-body activity to reveal them.
A strong core improves posture, protects the lower back, transfers force between the upper and lower body, and underpins performance in virtually every sport and lift. Train it deliberately using the popular core exercises below.