AT meaning in Sports ?

Athletic training has been recognized by the American Medical Association (AMA) as an allied health care profession since June 1991.

Athletic trainers (ATs) are health care professionals who render service or treatment, under the direction of or in collaboration with a physician, in accordance with their education, training and the state's statutes, rules and regulations. The practice of athletic training encompasses health promotion and wellness and examination, diagnosis, immediate care, and rehabilitation of clients/patients with emergent, acute, and chronic health conditions.

There are five domains of athletic training listed in the 7th edition (2015) of the Athletic Training Practice Analysis:

An athletic trainer functions as an integral member of the health care team in clinics, secondary schools, colleges and universities, professional sports programs, and other athletic health care settings.