Motion-Activated Support. Designed To Offer Lightweight Comfort While You Run, This Bras High-Impact Support Kicks In As Your Pace Quickens. Designed For Running. Intended For Running And High-Impact Training. Support Code Technology Maps A Unique Pattern Of High-Impact Support And Breathability Throughout The Bra, When Youre Not In Motion, It Feels Barely There. As Your Workout Intensifies, It Reduces Breast Movement Without Feeling Compressive, Built-In Moulded Cups Soften Bounce And Provide Shaping, Straps Are Padded For Comfort, Soft Foam Under Bust For Cushioning, Racerback Straps Stay Put, Keyhole In The Back For Airflow, Free-Cut Seams For A Sleek Look And Feel.