The book continues the “Smart Fitness” series. Unlike the three previous ones - “Smart Fitness. Leader's Book", "Smart Fitness. Trainer's book" and "Sensible fitness. Competitive Wars" - this publication is intended for clients of fitness clubs. There are no training methods here, but issues that are not usually covered in the literature are discussed in great detail. These are the problems of choosing a club and a coach, criteria for the quality of classes, features of interaction between the client and the club and some important legal features of this interaction. Particular attention is paid to those who want to study in the club on their own. The book gives basic concepts about choosing a load, the features of certain types of training. Separately, issues of maintaining and promoting health, preventing specific “fitness injuries” and diseases are considered. The publication will also be useful to those who work in the fitness business - trainers, specialists and managers. The book is written in lively language, and this, along with a large number of examples from practice, is a kind of calling card of the author.