Of course it works. Why don't you ask the personal trainer? The personal trainer's hands-on teaching is certainly better than the average. First of all, personal trainers know more than ordinary trainers, which is convenient for fitness, such as diet, movements and so on. It is also effective to practice by yourself. Unless you know how to keep fit, the effect of practicing blindly by yourself is not obvious. See if you want to practice strength or bodybuilding.