PERSONALITY AND SELF-EFFICACY FACTORS IN WEIGHT MAINTENANCE AFTER WEIGHT REDUCTION PROGRAM / 体力科学

The aim of this study was to examine a weight reduction program and residual effects, through confirming the relationship between changes in the morphological and psychological indices including personality and self-efficacy (SE) of the participants. Twenty-five middle-aged women were divided into two groups based on type of weight reduction program intervention. Thirteen women participated in a 3-month diet-only weight reduction program (DO group, 53.3±7.4 yr), and 12 women took part in a 3-month diet and aerobic exercise program (DE group, 48.3±9.6 yr). After the programs, the compatibility score of personality in the DO group was negatively correlated to SE that is indicated as confidence in ability to maintain decreased body weight at 2, 3, and 4 years after the program (r=-0.69, -0.58, and -0.60). It can be seen that personality has an effect on the results of the DO group weight reduction program. Additionally, despite a significant decrease in body-weight and %fat in both groups, only the change of %fat significantly correlated with SE. On the basis of these correlations, the changes of %fat that related to the movability perception of body movements has a greater effect on SE after the program than the information only of weight loss. The results of this study suggest that personality and SE accounted for weight maintenance, and were associated with the results of the weight reduction program.

EFFECTS OF AEROBIC TRAINING ON VISCERAL FAT AND GLUCOSE METABOLISM IN OLDER ADULTS / 体力科学

Excess accumulation of visceral fat is reported to promote insulin resistance. However, it is not known whether or not insulin resistance improves without reducing visceral fat. Recent studies have reported, however, that exercise can improve insulin resistance. The aim of this study was to examine the effects of low-intensity exercise training on insulin resistance and visceral fat. Participants were 26 older adults, aged 63.9 ± 3.9 years, who were divided into two groups based on visceral fat area (VFA, cm²) measured by X-ray computed tomography. Eight men (153.4 ± 49.4 cm²) and 5 women (151.9 ± 45.5 cm²) were classified as having a VFA of 100 cm² or more (VFO group), and 6 men and 6 women as having less than 100 cm² (C group). After a 14-week exercise training program, VFA in women of the VFO group was significantly reduced (126.3 ± 40.0 cm²) ; though it did not reach 100 cm². However, homeostasis model assessment (HOMA-IR), an index of insulin resistance, significantly improved from 4.6 ± 1.9 to 2.2 ± 1.1 among women in the VFO group. These data suggest that improvements in insulin resistance for women with relatively high VFA are weakly associated with exercise-induced reductions in VFA. Based on these results, the activation of skeletal muscle with physical activity has the possibility of being independently associated with an improvement in insulin resistance without a significant decrease of VFA.