Russian Twist

Move · Resistance Training · Movement, Typed Supps

Most of the work is holding the lean, not making the turn — the side muscles are fighting gravity long before the weight moves sideways.

Stage by stage

Set-up (Lean angle sets the torque): How far back you sit determines the gravitational load on the trunk, before any weight or rotation is added.
During the set (Isometric hold plus rotation): The obliques hold the trunk against extension throughout, with the side-to-side movement layered on top.
Where the turn happens (Thoracic spine and hips rotate): The lumbar spine permits little axial rotation; most visible turn comes from the upper back and pelvis.
Weeks later (Control, then strength): Balance and rotational timing improve first; oblique strength that transfers to carries and bracing follows over months.

Muscles trained

Primary: obliques
Secondary: abs, hip flexors

Intensity

3.8 METs (Calisthenics (e.g., push ups, sit ups, pull-ups, lunges), moderate effort).

Time to effect

Weeks: Rotational control and balance in the seated position improve first, often before any real strength change shows up.
Months: Oblique strength increases, which shows up as better resistance to unwanted trunk rotation elsewhere — carrying an uneven load, or bracing through a heavy squat.

Common myth

"Russian twists burn belly fat off your sides." In reality: No exercise burns fat specifically from the area it trains — this is spot reduction, and it does not hold up under research. Russian twists strengthen and can add size to the obliques underneath, but whether that muscle becomes visible depends on overall body fat, which is set by total energy balance, not by which muscle worked hardest that day.