Dead bug
The single best fit for you — it trains your back to resist the exact movement that hurts it.
Lower back pressed flat to the floor the whole time. If it lifts, the rep is over.
- Lie on your back, arms pointing at the ceiling, knees bent up over your hips.
- Flatten your lower back into the floor. Keep it there.
- Slowly lower one arm overhead and the opposite leg out straight.
- Stop the moment your back starts to lift. Come back. Swap sides.
Test yourself: slide a hand under your lower back. If you can feel a gap opening as you extend, you've gone too far — shorten the range.
3 sets · 8 reps each side · slow, ~4s per rep