This study rigorously examines breast motion dynamics in running, jumping rope, and high knee skips to guide sports bra design. Through motion capture and MATLAB analysis, researchers identified unique displacement patterns. Running displayed an erratic horizontal figure-eight trajectory, jumping rope exhibited a vertical elongated path, and high knee skipping resembled a butterfly shape. Without a bra, high knee skipping caused the most significant breast displacement, particularly in superior-inferior (68.54–74.89 mm) and medial-lateral (47.02–65.99 mm) movements. Jumping rope showed notable superior-inferior (47.88–63.69 mm) but minimal medial-lateral (9.08–14.05 mm) displacement. Running had minimal superior-inferior motion (9.73–36.61 mm) but more significant medial-lateral movement (15.72–49.17 mm). Exercise intensity directly impacted breast motion, with high knee skipping generating the highest accelerations (medial-lateral: 1.52g; superior-inferior: 4.18g). Sports bras should provide tailored support: medial-lateral for running, superior-inferior for jumping rope, and multidirectional for high knee skipping, with customizable features.