A personal trainer is a fitness professional who develops and implements an individualized approach to physical fitness, generally working one-on-one with a client. A trainer may also help an individual assess their level of physical fitness and help them work toward a personal fitness goal through proper exercise instruction and personal motivation.

Athletic personal trainers help prevent and treat injuries for people of all ages. Their clients include everyone from professional athletes to industrial workers. Recognized by the American Medical Association as allied health professionals, athletic trainers specialize in the prevention, assessment, treatment, and rehabilitation of musculoskeletal injuries. Athletic personal trainers often are one of the first heath care providers on the scene when injuries occur, and therefore they must be able to recognize, evaluate, and assess injuries and provide immediate care when needed. They also are heavily involved in the rehabilitation and reconditioning of injuries. Athletic trainers should not be confused with fitness trainers or personal trainers, who are not health care workers, but rather train people to become physically fit.