A personal trainer is someone who helps people meet their fitness goals, including but not limited to weight loss, strength training, toning, or overall health management. Unlike an athletic trainer, a personal trainer does not need a bachelor's degree to work with clients, although the majority of gyms and fitness centres require their trainers to hold general PT certifications.

Clients can range wildly in their physical fitness levels, so a trainer may be introducing one client to basic exercises, helping a second one with a weight loss program, and assisting a third in advanced training goals.