The purpose of the present study was to develop a scale to measure individual differences in health-related life skills in adolescents, and to examine the relationship between evaluation of health-related life skills and sport experience. The scale was based on a framework of health defined by WHO (1994), which includes 3 aspects: physical, psychological, and social. In study 1, we analyzed 1755 adolescents (846 junior high school students, 557 high school students, and 352 university students). A factor analysis for each of the 3 scales was conducted to find the factor component. Consequently, 6 factors were extracted: physical skills (physical activities skills and health maintenance skills), psychological skills (goal pursuing skills and coping skills), and social skills (collective bahavior skills and interpersonal skills). The results also showed that the scale was moderately reliable and valid for measuring health-related life skills in adolescents. In study 2, another survey was carried out on 304 high school students who had experience in athletic activities and 215 students who had not experienced athletic activities. From the results, it was clarified that students who had experienced athletic activities acquired more health-related life skills than students who had not experienced athletic activities. These results suggested that sport experience influences health-related life skills.

　The purpose of this research study was to determine whether or not visual function of baseball players would be improved by specific training. A total Forty-four male baseball players (age: 20.7±1.4, athletic career: 11.0±2.5 years) voluntarily participated in this study. The sample subjects were divided into three groups : Experimental group I, Experimental group II, and Control group. Sample subjects in the experimental group I were assigned to be trained with using the Speesion (computer software program for improving and measuring visual function), while the subjects of the experimental group II practiced watching high speed pitched baseballs and identifying the color of stickers on a ball. All the subjects underwent a usual baseball practice six days a week. Both experimental groups conducted a training session three times a week for eight straight weeks on top of the usual practice. The following items were measured by ordinary device for all sample subjects, static visual acuity (SVA), dynamic visual acuity (DVA), and Kinetic Visual Acuity (KVA). In addition, the following items were examined by the Speesion, DVA, eye movement, visual field, and moment perception. The measurements were conducted three times: at the prior to, after the 4th weeks, and at the end of the training sessions. No significant change in DVA and KVA was found in either experimental group when the ordinary testing devices were employed. However, by using the Speesion tests, significant improvements in some visual functions were found in both experimental groups. Therefore, the training methods utilized in this project improved the visual functions of the college male baseball players.

　Information about seasonality in the measurement of diet-induced thermogenesis (DIT) is important for understanding the intra-individual variability of DIT and the contribution of DIT on weight regulation. In this study, the seasonal change of DIT in autumn and winter were investigated for young women (N = 14, 18 – 24 yrs). The DITs of subjects were measured in autumn and winter. The DIT, body weight, body mass index (BMI) and percent body fat of each subject were measured on four or more occasions in each season for precision, and the mean value was used as the individual's value for a given season. The mean outdoor temperatures at starting measurement in the morning were 22°C in autumn, and 11°C in winter. The means of body weight, BMI and percent body fat did not change between seasons. DIT (%) significantly declined from autumn to winter (p < 0.05, Paired t-test). For DIT curve (the increase of postprandial energy expenditure during 300 min after meal), significant main effect of season was observed (ANOVA, p < 0.05, autumn > winter).

　In conclusion, there is the seasonal effect on DIT measurement; it declines from autumn to winter. The seasonality would be needed to be considered in any future study of DIT.

　The purposes of this study were to determine dynamic characteristics of muscle in preadolescent boys from relationship of isometric, concentric and eccentric torque, and effects of growth and development in dynamic characteristics of muscle. Thirteen healthy boys performed maximal efforts of elbow flexion to obtain maximal torque during isometric, concentric and eccentric action. Electromyographic activities of biceps brachii and brachioradialis were also recorded to measure motor unit activation (MUA) during maximal efforts. To determine the dynamic characteristics of muscle in preadolescent boys, maximal isometric (P₀), concentric (P_CON) and eccentric torque (P_ECC) were analyzed by Hill equation and repeated one-way ANOVA. As a result, relative eccentric torque (P_ECC /P₀), which showed 1.19±0.23, was obviously lower than that of adults, and it appeared to stem from the fact that the boys showed less than 1.0 P_ECC/P₀. To determine the individuality of P_ECC/P₀, subjects were divided into two groups by P_ECC/P₀ above 1.0 (high group) or under 1.0 (low group) and then MUA of both groups were compared by repeated two-way ANOVA (group × region of muscle). Consequently the activation level in both regions of muscles of the low group was significantly lower than the high group, and there was no significant interaction. Therefore, it is suggested that the dynamic characteristics of muscle in preadolescent boys are similar to those of adults during isometric and concentric action, and there are effects of growth and development on characteristics of muscle in boys during eccentric action.