Butt-Ups
Butt-ups start from a straight-arm plank and ask you to drive your hips up and back into a pike shape, then lower back down under control. It's a bodyweight ab exercise with no equipment needed, and it suits anyone who's comfortable holding a plank and wants a movement, rather than a static hold, to build core strength.
Why it works
Your abs' main job is pulling your ribs and pelvis toward each other, and lifting your hips up out of a plank does exactly that against your own body weight. Keeping your arms and legs straight while your hips travel means your abs have to do the lifting instead of your shoulders or hip flexors taking over, which is different from a floor crunch where gravity only resists a small range near the top of the movement.
Set up
- Get into a straight-arm plank with your hands and toes on the floor.
- Set your hips level with your shoulders so your body forms a straight line.
- Keep your arms locked and your feet a comfortable width apart.
How to do it
- Drive your hips up and back, keeping your legs straight, until your body forms an inverted V.
- Pause briefly at the top of the movement.
- Lower your hips back down under control until you're back in a straight plank line.
- Repeat without letting your hips sag below shoulder height at the bottom.
Form cues
- Keep your arms straight the whole time, the lift comes from your hips, not your shoulders.
- Drive the movement from your abs pulling your hips up.
- Lower slowly instead of dropping back to the plank.
- Keep your neck relaxed and your gaze down.
Breathing: Exhale as your hips rise into the pike, and inhale as you lower back down to the plank position.
Common mistakes
Bending the elbows to help push the hips up.
Fix: Keep your arms locked out. If you need to bend them to finish the rep, the load is too much for now, so try the bent-knee version instead.
Dropping quickly back to the plank after each rep.
Fix: Lower over two or three seconds so your abs stay under tension the whole way down instead of just at the top.
Letting your hips sag toward the floor at the bottom of each rep.
Fix: Reset to a straight plank line every time. A sagging lower back means the rep has already ended.
How to program it
- This is a bodyweight ab movement with a fairly light fatigue cost, so it fits well two or three times a week as part of a core circuit.
- Ten to fifteen reps is a reasonable working range. If you're grinding out fewer than eight with good form, the bent-knee regression is the better fit for now.
Safety notes
- Stop if your wrists ache and try making fists or resting on a folded mat instead of flat palms.
- Keep your neck neutral rather than craning it up to look forward.
- Skip this one for now if you have an existing wrist or shoulder injury, since it loads both under body weight.
Exercise profile
- Force
- Pull
- Mechanics
- Compound
- Category
- Strength
Frequently asked questions
How many reps of butt-ups should I do?
Ten to fifteen clean reps is a good target. If your form breaks down earlier than that, fewer reps with good control beats more with a sagging plank.
Do I need any equipment for butt-ups?
No. All you need is enough floor space for a plank position.
What's the difference between butt-ups and a regular plank?
A plank is a static hold in one position. Butt-ups move continuously, lifting your hips into a pike and lowering back down, which asks your abs to control motion rather than just resist it.
Why do I feel this more in my lower back than my abs?
That usually means your hips are sagging at the bottom of the rep instead of staying in a straight plank line. Reset your hips level with your shoulders before each rep and keep the range shorter if needed.