A Study on Body Fat in Young Athletes

-The Changes in Obesity Level of Rugby Football Players During the Training Season-

Abstract

It is important to examine effects of exercise on body composition of athletes in understanding their desired fat weight and fat percentage. In this study, changes in the obesity level were investigated for 29 rugby football players (11 forward players and 18 backs players) and 31 non-athletes as the control, all of whom were students in the same university, before and after the football season in 1994. Major results were as follows. 1. There were three major observations in comparison of changes in obesity level between the player group and the control group. First, fat weight and fatpercentage of the player group significantly decreased during the season (by paired t-test), whereas those of the control group did not. Second, according to measurements by A-mode type ultrasonic device, subcutaneous fat thickness of the player group became significantly thinner on all measurement points during the season, whereas such decreases of the control group were observed only on legs and arms. Third, increase of lean body weight during the season occurred only in the player group. 2. Three methods, i.e. A-mode type ultrasonic device method, sulfur hexaf luoride (SF6) dilution method, and body mass index (BMI) method, were applied todetermination of the obesity level. Among them, A-mode type ultrasonic device method was demonstrated to be the most sensitive to changes in obesity level caused by training among the player group.