A Certified Personal Trainer is a fitness professional who has completed a certification program to gain knowledge in exercise science, nutrition, and client assessment. They help individuals achieve their fitness goals by creating personalized workout plans and providing guidance on proper exercise techniques. These trainers often hold certifications from recognized organizations, such as the American Council on Exercise or National Academy of Sports Medicine. They work in various settings, including gyms, private studios, and clients' homes, and may specialize in areas like weight loss, strength training, or rehabilitation.