The trainer in the gym is a service specialist on a par with a hairdresser, chef or maid. If we dream of high-quality hair coloring, we go to a professional in a beauty salon. If there is no desire to clean the apartment, we order cleaning. It's the same with fitness: in order to get a beautiful figure without harm to health, we turn to a trainer. If you just sweat on the treadmill and pull incomprehensible glands in the gym, you will not achieve the desired effect. For example, the basic squat exercise is one of the most difficult in technique. If done incorrectly, it is easy to injure knee joints or get herniated discs.
The trainer conducts group and personal trainings. On personal, it takes the student under complete control in terms of exercise, motivation, and even nutrition. It all depends on the client's desire - to lose weight, gain weight or become healthier in general. In programs, this sounds more weighty: "to reduce fat mass, gain muscle mass and rehabilitate after injury or childbirth."
For each individual client, the trainer develops a training plan, which takes into account all diseases, injuries and the level of physical fitness. For example, one of my clients has varicose veins. The load on the legs is contraindicated for him, you can not do a single exercise while standing. He performs all tasks while sitting or lying down. Squats and all types of deadlifts are also contraindicated for him, for example, you cannot lift a barbell from the floor. For a healthy person, these exercises are basic, but we have selected others for him.