Hold a forearm plank with perfect form — body in a straight line, core braced, hips level. Slowly reach one arm forward, hold 2 seconds, return. Alternate arms. If your hips rotate or drop, reduce the reach distance.
Why it matters
This is whole-chain stability — it trains your shoulders, core, and hips to work together under load. That coordination is exactly what your nervous system needs to produce a consistent, powerful, injury-free swing.