Training and Detraining Effects of Low Intensity Resistance on Functional Fitness in Postmenopausal Women

Abstract

PURPOSE: To investigate the changes in the body composition and functional fitness after one year of low intensity resistance training, and 24 weeks of detraining in postmenopausal women. METHODS: Sixteen healthy volunteers matched for strength were assigned to a control (n=7, age: 55.26±3.09 yrs, BMI: 23.89±5.02 kg/m2) or exercise group (n=9, age: 55.67±4.74 yrs, BMI: 23.51±5.79 kg/m2). The exercise group was instructed to a supervised progressive high repetition/ low resistance training 1 hour, 2 days per week for one year by using the elastic bands or body weight for resistance. Duel-energy X-ray absorptiometry (DXA) was used to measure subjects' body composition. The body fat, lean body mass, and senior functional fitness including flexibility, muscle strength, muscle endurance, aerobic endurance, and body agility/dynamic balance were assessed at baseline, after training and detraining. The Mann-Whitney U test was used for data analysis. RESULTS: After one year training, the exercise group demonstrated significant improvements in aerobic endurance (69%; 2-minute stepping), muscle endurance (112%; 60-second abdominal crunch), and agility/dynamic balance (11%; 8-foot up-and-go). The fat mass of trunk and the percentage of total body were significantly greater in exercise group than the control groups (p<.05). In addition, the aerobic endurance of the functional fitness, and fat mass of the leg in the exercise group were still greater than the baseline after 24 weeks of detraining, but muscle endurance, agility/dynamic balance, and flexibility declined significantly after detraining in the exercise group. CONCLUSIONS: Low intensity resistance training using elastic band can reduce body fat and improves functional physical fitness in postmenopausal women. However, the interrupting exercise has negative effects on several physical parameters of functional fitness and body composition.