Men's soccer sports bras: Why are they wearing those GPS harnesses?

The Nike Alpha Menace 3 Shark has an aggressive rubber sole designed to grip the ground while flexing with your foot so you can unleash your speed during practice or play. It updates the previous version with overlays at the midfoot to give you secure support when you juke, spin and cut your way down the field. The 3rd edition adds another layer of containment and support with wings on the sides that integrate with the laces for a secure fit.