Russian Twist.
The Russian twist trains the obliques and rotational core through repeated trunk rotation from a seated, reclined position. The V-shape between torso and thighs keeps the hip flexors loaded and the abdominals working isometrically to hold position while the rotation is happening.
Step by step.
Sit on the floor with your knees bent and feet flat in front of you. Anchor the feet down or have a partner hold them while you learn the movement.
Lean back until your torso is at about 45 degrees from the floor. Far enough that your abs have to fight to hold the position, but not so far that you are nearly lying down.
Hold a plate or medicine ball with both hands and extend your arms out in front of your chest. Brace your trunk so the spine stays steady.
Lead with your ribcage and rotate to one side until your hands pass over your hip and your arms point parallel to the floor. The rotation comes from the trunk, not from swinging the arms alone.
Rotate back through the center and continue to the other side under control. Keep the torso angle the same on both ends.
Move slowly rather than fast. Once the rotation stays clean, you can lift your feet off the floor to hold them up against gravity and make it harder.
The angle of the torso lean is what separates a real Russian twist from a hip flexor exercise with arms waving side to side. Lean back until you're at about 45 degrees from the floor, far enough that the abs have to work to hold the position, not so far that you're basically lying down. Many people sit too upright, which eliminates the anti-gravity demand on the core and turns the rotation into pure shoulder movement. Others go too far back, at which point the hip flexors are screaming and the obliques are doing very little.
The rotation needs to come from the ribcage, not the arms. Arms extended out front, hands clasped or holding a plate. Rotate until the hands are parallel to the floor on one side. That's full oblique involvement. If you're just swinging your arms left and right while your torso stays fairly fixed, you're doing a different exercise. Think: lead with the sternum, not the hands.
With weight (a 10-25 lb plate is plenty for most people), the focus should be control, not speed. Fast rotations with a heavy plate turn into ballistic shoulder work and strain the lumbar rotators if the spine position isn't locked down. Slow, deliberate rotation to full range on each side is more effective and less likely to bother the lower back.
Feet anchored or feet raised are two distinct exercises. Feet on the floor or held by a partner stabilizes the hips and lets you focus on rotation. Feet raised (legs bent, off the floor entirely) adds an anti-flexion hold and challenges the hip flexors more. Start anchored. Progress to raised once the rotation quality is consistent.
Rotation is all this trains, so it can't carry your whole core. Bolt it onto a flexion movement like the hanging leg raise so the midsection gets trained through bending as well as twisting. For loaded rotation, the cable woodchop adds a standing diagonal pattern, the medicine ball russian twist and plate twist let you scale the weight, and the bicycle crunch mixes flexion in with the rotation.
Common questions.
Primarily the external and internal obliques through rotational trunk movement. The rectus abdominis works isometrically to hold the reclined position. The hip flexors contribute to maintaining the V-angle. The exercise is commonly categorized as an oblique exercise, which is accurate. The rotation against the lean is a genuine oblique-dominant pattern. Where people expect too much: the Russian twist doesn't produce meaningful ab hypertrophy from the isometric hold alone. Pair it with exercises that load spinal flexion directly (hanging leg raises, weighted crunches) for a complete approach.
Yes, when you can maintain form without it. A medicine ball, weight plate, or dumbbell held with both hands increases the rotational resistance and the demand on the obliques. Start with bodyweight until the full rotation range is consistent (arms parallel to the floor on each side, torso angle stable throughout). Then add 5-10 lbs and rebuild quality at that load. The common mistake is going to 25+ lbs immediately, which causes the torso angle to collapse and turns the exercise into something between a hip flexor strain and a shoulder flail.
Rotational exercises under spinal flexion load are one of the higher-risk patterns for people with existing disc issues. The Russian twist combines a slightly flexed spine with rotation, which is the movement pattern most associated with disc shear in research on spinal biomechanics. For people with a healthy spine, the exercise is fine with good form. For anyone with disc herniation, lower back pain, or a history of lumbar injury, rotational exercises on a stable spine (like Pallof presses or cable woodchops from standing) are a safer starting point. Get clearance from a physio if you're unsure.
The Russian twist rotates the torso in a seated position at a fixed angle from the floor. It's a closed-chain oblique exercise with no resistance except what you're holding. The cable woodchop pulls against external resistance through a standing or half-kneeling rotation, training the obliques and hips against a consistent load through the full range. The woodchop is generally considered superior for training anti-rotation strength and has more carry-over to sport and functional movement. Russian twists are a reasonable bodyweight option when cables aren't available, but they're not a replacement.
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