Using such methods as literature review and exper-imental research, this paper carried out an investigation on 30 adolescent students (15 boys and 15 girls) from the 2014 swim-ming training class of Yiyang Olympic Natatorium. A 12-week swimming training was carried out, and an experimental research was then made to compare their body composition and cardio-vascular function before and after the training. The indexes of body composition (BMI coefficient, and body fat percentage) and cardiovascular function (blood pressure, heart rate, and stroke volume) were measured. The result shows that: ado...