TETSUBottoms-Up vs Kettlebell Windmill
The Bottoms-Up and the Kettlebell Windmill both train the abs as their primary muscle. The Bottoms-Up is bodyweight-only while the Kettlebell Windmill uses a kettlebell. Here is how they compare and when to pick each.
Side-by-side comparison
| Bottoms-Up | Kettlebell Windmill | |
|---|---|---|
| Primary muscle | abs | abs |
| Body part | waist | waist |
| Supporting muscles | obliques and hip flexors | obliques and shoulders |
| Equipment | bodyweight | kettlebell |
| Steps in our guide | 5 | 6 |
How each one starts
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.
Kettlebell Windmill — first steps
- Stand with your feet shoulder-width apart, holding a kettlebell in your right hand overhead.
- Rotate your left foot outwards about 45 degrees and keep your right foot pointing forward.
Full step-by-step guides are linked below.
Which should you choose?
The Bottoms-Up needs no equipment and scales through leverage, tempo and reps. The Kettlebell Windmill shifts the load off-center, adding grip and stabilizer demand. 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 Bottoms-Up better than the Kettlebell Windmill?
Neither is universally better — both train the abs as the primary mover. The Bottoms-Up needs no equipment and scales through leverage, tempo and reps, while the Kettlebell Windmill shifts the load off-center, adding grip and stabilizer demand. Choose based on your equipment and which movement you can progress consistently.
Can I do both the Bottoms-Up and the Kettlebell Windmill 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 Bottoms-Up and the Kettlebell Windmill work the same muscles?
The primary muscle is the same: the abs. Supporting muscles differ slightly — obliques and hip flexors for the Bottoms-Up versus obliques and shoulders for the Kettlebell Windmill.
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.