Horizontal refers to horizontal line, horizontal plane, quantity, intensity, level and grade.

Level 1: fitness rookie. This kind of person, mostly on a whim, may just come to the gym for a moment of freshness and blood.

Level 2: Beginners are on the road. They will have a certain sense of protection, and will prepare sportswear, comfortable sports shoes and even a little sports protective equipment in advance before fitness.

Level 3: Fitness expert. People at this stage have probably accumulated for a long time. He must have more than one set of sports equipment. For example, for daily running, they will choose professional running shoes and quick-drying sportswear, and girls will wear sports bras. May be paired with sports bracelets, Bluetooth headsets and knee pads.