Fit is great for running. Amount of warmth is perfect level for days in the 30s and layered for lower. All made even better because washing is so easy. Machine wash inside out, hang dry. So easy. This is my second Ambition top because my first was the perfect blend of great looks, great fit, high visibility, warmth, easy care. I even bought one for my running buddy as her Xmas gift. She loves it too.