TETSUBarbell Side Bent vs Flag
The Barbell Side Bent and the Flag both train the abs as their primary muscle. The Barbell Side Bent uses a barbell while the Flag is bodyweight-only. Here is how they compare and when to pick each.
Side-by-side comparison
| Barbell Side Bent | Flag | |
|---|---|---|
| Primary muscle | abs | abs |
| Body part | waist | waist |
| Supporting muscles | obliques and lower back | obliques and shoulders |
| Equipment | barbell | bodyweight |
| Steps in our guide | 6 | 6 |
How each one starts
Barbell Side Bent — first steps
- Stand with your feet shoulder-width apart and hold a barbell with both hands, palms facing down.
- Keep your back straight and core engaged throughout the exercise.
Flag — first steps
- Start by gripping a vertical pole with both hands, palms facing each other, and arms fully extended.
- Engage your core and lift your legs off the ground, keeping them straight.
Full step-by-step guides are linked below.
Which should you choose?
The Barbell Side Bent lets you load the heaviest weights and progress in small, steady jumps. The Flag 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 Barbell Side Bent better than the Flag?
Neither is universally better — both train the abs as the primary mover. The Barbell Side Bent lets you load the heaviest weights and progress in small, steady jumps, while the Flag 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 Barbell Side Bent and the Flag 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 Barbell Side Bent and the Flag work the same muscles?
The primary muscle is the same: the abs. Supporting muscles differ slightly — obliques and lower back for the Barbell Side Bent versus obliques and shoulders for the Flag.
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.