Body Composition In Japanese Middle-aged And Elderly Female Swimmers

Abstract

PURPOSE The purpose of this investigation was to examine body composition in middle-aged and elderly female swimmers using the cross-sectional design. METHODS A total of 62 Japanese women aged 39–75 yr who were either sedentary or swimming trained were studied. Systemic and regional body compositions were measured by dual-energy x-ray absorptiometry (DEXA). Maximal aerobic capacity (VO2max) was determined by using a graded exercise test on a treadmill. Leg extension power was measured by Anaero Press 3500. Metabolic risk factors, such as total-cholesterol, HDL-cholesterol, triglycerides, glucose and HbA1c, were analyzed. A personal questionnaire was used to record the frequency of swimming, age at menopause, and other personal medical data. The data are presented as the mean ± SD. Statistical analysis was performed using unpaired t-test. Statistical significance was defined as p<0.05. RESULTS There were no significant differences in age, height, weight, and metabolic risk factors between the two groups (sedentary: n = 20, Age 60.3 ± 8.4yr., Ht 155.4 ± 4.8cm, BW 58.5 ± 10.0kg, swimming: n = 20, 59.4 ± 7.5yr., 154.6 ± 4.9cm, 54.3 ± 7.4kg). VO2max was significantly higher in swimming group compared with sedentary group (swimming vs sedentary: 33.9 ± 5.1 vs 28.3 ± 4.8 ml/kgBW/min, p<0.001). However, there was no significant difference in leg extension power between two groups. Whole body %fat in swimming group (28.2 ± 4.8%) was significantly lower than their sedentary peers (31.1 ± 5.0%). Furthermore, trunk, arms, and legs %fat in swimming group were significantly lower than those of sedentary women (trunk 26.2 ± 6.7 vs 31.2 ± 7.6, p<0.05, arms 31.6 ± 5.4 vs 37.9 ± 5.2, p<0.001, legs 28.2 ± 3.1 vs 31.1 ± 3.8, p<0.05). However there were no significant differences in fat free mass of whole body, arms, and legs between the two groups (swimming vs sedentary: whole body 38.8 ± 4.4 vs 40.0 ± 5.0kg, arms 3.6 ± 0.6 vs 3.5 ± 0.5kg, legs 12.9 ± 1.6 vs 12.9 ± 1.5kg). CONCLUSIONS The present investigation provided the evidence for suggesting the possibility that long term regularly performed swimming reduces fat mass and enhances aerobic capacity in middle-aged and elderly women. However, this study suggests that regular swimming exercise is not sufficient to increase fat free mass, especially appendicular muscle mass.