TETSUAssisted Motion Russian Twist vs Bottoms-Up
The Assisted Motion Russian Twist and the Bottoms-Up both train the abs as their primary muscle. The Assisted Motion Russian Twist uses a medicine ball while the Bottoms-Up is bodyweight-only. Here is how they compare and when to pick each.
Side-by-side comparison
| Assisted Motion Russian Twist | Bottoms-Up | |
|---|---|---|
| Primary muscle | abs | abs |
| Body part | waist | waist |
| Supporting muscles | obliques and lower back | obliques and hip flexors |
| Equipment | medicine ball | bodyweight |
| Steps in our guide | 6 | 5 |
How each one starts
Assisted Motion Russian Twist — first steps
- Sit on the ground with your knees bent and feet flat on the floor.
- Hold the medicine ball with both hands in front of your chest.
Bottoms-Up — first steps
- Lie flat on your back with your legs extended and your arms by your sides.
- Bend your knees and bring them towards your chest, keeping your feet off the ground.
Full step-by-step guides are linked below.
Which should you choose?
The Assisted Motion Russian Twist suits explosive, power-focused reps. The Bottoms-Up needs no equipment and scales through leverage, tempo and reps. If your gym has both options, neither is a wrong choice: pick the one that feels strongest through a full range, and swap after 6 to 8 weeks to keep the abs adapting.
Full form guides
Common questions
Is the Assisted Motion Russian Twist better than the Bottoms-Up?
Neither is universally better — both train the abs as the primary mover. The Assisted Motion Russian Twist suits explosive, power-focused reps, while the Bottoms-Up needs no equipment and scales through leverage, tempo and reps. Choose based on your equipment and which movement you can progress consistently.
Can I do both the Assisted Motion Russian Twist and the Bottoms-Up in the same program?
Yes, but usually not in the same session — they overlap heavily on the abs. A common setup is one as your main movement and the other on a second training day, or alternating them block by block.
Do the Assisted Motion Russian Twist and the Bottoms-Up work the same muscles?
The primary muscle is the same: the abs. Supporting muscles differ slightly — obliques and lower back for the Assisted Motion Russian Twist versus obliques and hip flexors for the Bottoms-Up.
Track it in Tetsu
Tetsu tracks both movements separately, keeps your PRs per exercise, and tells you which one is actually progressing. Free to start.