Russian Twist

How to do it

Sit with your knees bent and heels lightly on the floor. Hold the bell at your chest and lean back to a tall, supported position — chest up, back long. Rotate from your ribs (not your arms), tapping the bell beside one hip, then the other.

Why it's good for runners

Trains your core to rotate against resistance while keeping your spine stable — the same rotational stability your trunk uses every time your arm and opposite leg swing through.

Common mistakes

Don't round your lower back to reach further. If you feel it in your lower back, sit taller and slow down. The rotation should come from your ribs, not from collapsing your spine.