TETSU3/4 Sit-Up vs Weighted Russian Twist (Legs Up)
The 3/4 Sit-Up and the Weighted Russian Twist (Legs Up) both train the abs as their primary muscle. The 3/4 Sit-Up is bodyweight-only while the Weighted Russian Twist (Legs Up) adds external weight to a bodyweight pattern. Here is how they compare and when to pick each.
Side-by-side comparison
| 3/4 Sit-Up | Weighted Russian Twist (Legs Up) | |
|---|---|---|
| Primary muscle | abs | abs |
| Body part | waist | waist |
| Supporting muscles | hip flexors and lower back | obliques and hip flexors |
| Equipment | bodyweight | added weight |
| Steps in our guide | 5 | 6 |
How each one starts
3/4 Sit-Up — first steps
- Lie flat on your back with your knees bent and feet flat on the ground.
- Place your hands behind your head with your elbows pointing outwards.
Weighted Russian Twist (Legs Up) — first steps
- Sit on the ground with your knees bent and feet lifted off the ground, keeping your legs together.
- Hold the weight with both hands in front of your chest, keeping your elbows slightly bent.
Full step-by-step guides are linked below.
Which should you choose?
The 3/4 Sit-Up needs no equipment and scales through leverage, tempo and reps. The Weighted Russian Twist (Legs Up) adds external load to a bodyweight pattern for direct overload. 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 3/4 Sit-Up better than the Weighted Russian Twist (Legs Up)?
Neither is universally better — both train the abs as the primary mover. The 3/4 Sit-Up needs no equipment and scales through leverage, tempo and reps, while the Weighted Russian Twist (Legs Up) adds external load to a bodyweight pattern for direct overload. Choose based on your equipment and which movement you can progress consistently.
Can I do both the 3/4 Sit-Up and the Weighted Russian Twist (Legs 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 3/4 Sit-Up and the Weighted Russian Twist (Legs Up) work the same muscles?
The primary muscle is the same: the abs. Supporting muscles differ slightly — hip flexors and lower back for the 3/4 Sit-Up versus obliques and hip flexors for the Weighted Russian Twist (Legs 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.