Dead Bug

The lean starts when your trunk stops holding its shape. Late in a long effort, the deep core fatigues, the hip flexors win the tug-of-war, and you fold forward without ever deciding to. The dead bug is the antidote, because it trains the one thing running actually asks of your core: stay stable while everything around you moves.

This is an anti-extension drill. Your job is to keep your low back quietly pinned to the floor while your arms and legs try to pull it into an arch. Master that on the ground and you've built the reflex that keeps you upright at mile 80.

How to do it

Lie on your back, knees stacked over hips at 90 degrees, arms reaching straight at the ceiling. Gently flatten your low back into the floor and brace your abs — like you're about to take a light punch. Slowly lower your right arm overhead and straighten your left leg toward the floor at the same time. Go only as far as you can without your back peeling up. Return, then switch sides. That's one rep per side.

Cues that matter

• Exhale as you extend the limbs — the breath helps the brace.

• Keep your ribs down; don't let them flare toward the ceiling.

• The moment your low back lifts off the floor, you've gone too far. Shorten the range.

• Move slowly. This is control, not cardio.

Video Example: Hinge Health demonstrates Dead Bug

Dose it

2–3 sets of 6–8 slow reps per side. Friendly to do daily, even as a warm-up before a run.

Make it easier / harder

Easier: keep the moving leg bent, or just move the arms while the legs stay put. Harder: hold a light weight in each hand, slow the tempo to a 4-count, or add a band pull-overhead for more anti-extension load.