TETSU45° Side Bend vs Assisted Sit-Up
The 45° Side Bend and the Assisted Sit-Up both train the abs as their primary muscle. The 45° Side Bend is bodyweight-only while the Assisted Sit-Up is an assisted movement. Here is how they compare and when to pick each.
Side-by-side comparison
| 45° Side Bend | Assisted Sit-Up | |
|---|---|---|
| Primary muscle | abs | abs |
| Body part | waist | waist |
| Supporting muscles | obliques | hip flexors |
| Equipment | bodyweight | assisted |
| Steps in our guide | 5 | 6 |
How each one starts
45° Side Bend — first steps
- Stand with your feet shoulder-width apart and your arms extended straight down by your sides.
- Keeping your back straight and your core engaged, slowly bend your torso to one side, lowering your hand towards your knee.
Assisted Sit-Up — first steps
- Sit on the edge of a bench or have someone hold your feet down.
- Lie flat on your back with your knees bent and feet flat on the ground.
Full step-by-step guides are linked below.
Which should you choose?
The 45° Side Bend needs no equipment and scales through leverage, tempo and reps. The Assisted Sit-Up reduces the load so you can own the movement before going unassisted. 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 45° Side Bend better than the Assisted Sit-Up?
Neither is universally better — both train the abs as the primary mover. The 45° Side Bend needs no equipment and scales through leverage, tempo and reps, while the Assisted Sit-Up reduces the load so you can own the movement before going unassisted. Choose based on your equipment and which movement you can progress consistently.
Can I do both the 45° Side Bend and the Assisted Sit-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 45° Side Bend and the Assisted Sit-Up work the same muscles?
The primary muscle is the same: the abs. Supporting muscles differ slightly — obliques for the 45° Side Bend versus hip flexors for the Assisted Sit-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.