Dead Bug
Core training that teaches the spine to stay still while the limbs move — the real job of your abs.
Setup
- On your back: arms straight up, knees over hips at 90°.
- Press your lower back gently into the floor — keep that contact all set.
How To Do It
- Lower ONE arm overhead and the OPPOSITE leg toward the floor.
- Stop the instant your low back starts to peel up.
- Return and switch sides.
Breathing
Exhale slowly as the limbs lower.
Common Mistakes
- Both legs at once — that's a back-archer; opposite pairs only.
- Rushing — 3 seconds out, 3 back.
Programming It
Two to three sets of 8-12 per side, slowly.
Why This Exercise Works
It looks like nothing and it is one of the best trunk exercises there is. Lowering opposite limbs while the lower back stays flat on the floor trains the abs to hold the spine still while the limbs move — which is what the trunk actually does all day, as opposed to crunching.
Where You Should Feel It
Almost nothing, if done properly — a quiet, constant effort in the deep abs to keep the lower back flat. The moment you feel your lower back, the limb has gone further than you can control.
Where It Fits in a Program
Core training that teaches the spine to stay still while the limbs move — the real job of your abs. Everything else in the session should be arranged around this one.
Progressing and Regressing It
To progress the dead bug: extend the limbs fully, or hold a light weight in the hands. To regress it: move one limb at a time, and keep the knee bent.
Who It's For
Anyone with back trouble, and anyone who needs to learn bracing before loading it. It is the least impressive-looking exercise on the site and one of the most useful.
Equipment and Substitutions
This needs no kit at all, which makes it the one that survives travel, busy gyms and bad weeks.
Related Exercises
- Bicycle Crunch — Abs, Obliques
- Side-Lying Leg Raise — Glute Medius, Hips
- Reverse Crunch — Abs, Hip Flexors
- Bird Dog — Core, Low Back, Glutes
- Side Plank — Obliques, Core
- Mountain Climbers — Core, Conditioning
- Plank — Core, Shoulders
- Hollow Body Hold — Abs, Deep Core
Common Questions
What muscles does the dead bug work?
The dead bug primarily trains the deep core.
How many sets and reps should I do?
Two to three sets of 8-12 per side, slowly.
What are the most common dead bug mistakes?
Most often: both legs at once; rushing.
Can I do this without any equipment?
Yes — this version needs no equipment at all. It trains the deep core using bodyweight alone, which is why it travels well and works as a warm-up, a substitute, or a full session on its own.
Is this safe if I have an existing injury?
The dead bug loads the knee, hip and lower back together, which means a problem in any one of them can surface here. If a rep reproduces the pain you already have, stop the set and get it looked at. Not medical advice.