Swimming can strengthen the body, but playing games for a long time is harmful to physical and mental health.
Swimming can be divided into competitive swimming and practical swimming. Competitive swimming is the second largest event in the Olympic Games, including butterfly, backstroke, breaststroke, agility and synchronized swimming. Practical swimming includes military swimming, water rescue and snorkeling. Early swimming activities are often regarded as an important part of the education of aristocratic children and the training of soldiers. The ancient Romans built huge baths, and swimming became a social activity in the upper class. At the end of 18, the opportunities for workers to swim increased, and swimming began to become a universal sport.