When it comes to butterfly, the greatest demand for body core power isn’t at the entry or recovery — it’s in the second quadrant of the stroke, as the arms drive into the power phase and flick past the hips. This is the moment where swimmers must harness dynamic trunk control to maintain speed and create a seamless transition into a light, relaxed recovery over the top of the water. Without that deep core integration, the hips sink, velocity leaks, and rhythm breaks down — all costly mistakes in the latter half of a race. Advanced protractive strength drills like the tuck planche directly target this demand, training swimmers to manage hypermobile trunk and shoulder positions with precision. By practicing this balance of protraction and retraction, athletes learn to stabilize the serratus anterior and keep the stroke trajectory clean, even under fatigue. Over time, this translates to greater strength endurance, reduced leakage, and the ability to sustain rhythm and velocity when it ma...