Research shows that every time a woman runs 1 mile, her chest shakes 135 meters (equivalent to 85 meters per 1 kilometer)! Imagine that after running a marathon, your chest is basically disabled, not to mention all kinds of strangulation and abrasions caused by the shoulder straps around your chest ... If your chest is relatively large, the maximum jumping amplitude of this pair of chest devices can reach 14cm during intense exercise (even in the 34A/75A chest test, their vibration amplitude can reach 4cm). There is no muscle in the breast, only ligaments and skin play the main supporting role. Once injured, it is almost irreversible. If you wear a sports bra, things will be very different. Can effectively reduce 78% of chest tremors! So buy a sports bra quickly.