The purpose of the study was to determine the effect of 8 weeks pre-season training on body composition, physical fitness, anaerobic capacity, and isokinetic strength in collegiate taekwondo athletes. Thirty-four collegiate athletes (male: 22, female: 12) participated. Body composition, bone mineral density, physical fitness, anaerobic capacity, and isokinetic muscle strength were tested. After statistical analysis was performed the results indicated that there were significant decreases in body weight, percent body fat, and fat tissue after 8 weeks of pre-season training. Bone mineral density increased significantly only in males. There were significant improvements in the 50 m shuttle run and 20 m multistage endurance run in both males and females. The sit & reach test and standing long jump were not significantly changed after 8 weeks. Relative peak power and anaerobic capacity were significantly improved in males. Significant increases in angular velocity were observed for knee extension at both % BW 60°/sec and 180°/sec in both males and females. A significant increase in angular velocity was seen for right knee flexion at % BW 60°/sec for males, but it decreased at % BW 180°/sec for both males and females. In conclusion, this study suggests that 8 weeks of pre-season training has a positive effect on body composition, physical fitness, anaerobic capacity, isokinetic muscular strength, and endurance. Nevertheless, an exercise approach with the goal of increasing lean tissue, and improving power in knee flexors and flexibility of athletes, should be included in the training program.

The purpose of the study was to analyze changes in physique, body composition, physical fitness, and isokinetic strength in female collegiate taekwondo athletes. The study included 14 subjects, of whom 8 were followed up throughout the study. Anthropometric characteristics included body weight, height, sitting height, circumferences, and bone width. Physical fitness parameters included flexibility, agility, muscle strength, muscular endurance, power, speed, and cardiorespiratory endurance. Peak torque, mean power, and H/Q ratio were analyzed by using Cybex 770. All data were analyzed by using the SAS statistical program. Paired t test was performed, with 0.05 as the significance level. The results indicated significant changes in body weight, and upper arm and flexed upper arm circumferences during the experimental period. Test scores for plate tapping, and sit and reach significantly increased, but that for power decreased. In addition, the peak power of right flexion at 180°/sec was significantly increased, as well as the mean power of right and left flexion, and the H/Q ratio at 180°/sec.

The study aimed to determine the effects of bone-specific physical activity on body composition, bone mineral density (BMD), and health-related physical fitness in middle-aged women.[Methods] One hundred eighty-six middle-aged women aged 31-49 years participated in this study. The subjects were divided into tertile groups according to the level of physical activity (low-score group, n=62; middle-score group, n=62; high-score group, n=62). Bone-specific physical activity participation was assessed using the bone-specific physical activity questionnaire. Body composition and BMD were measured using dual-energy X-ray absorptiometry. Health-related physical fitness test included isometric muscle strength (grip strength), muscular endurance (sit-ups), flexibility (sit and reach), and cardiorespiratory fitness (maximal oxygen uptake [VO2max]).[Results] The high-score group had a significantly higher fat-free mass (p=.045, partial eta-squared value [ηp 2 ]=.033) than the middle-and low-score groups, whereas the high-score group had significantly lower percent body fat (p=.005, ηp 2 =.056) than the other two groups. Whole-body BMD (p=.034, ηp 2 =.036) and lumbar BMD (p=.003, ηp 2 =.060) were significantly higher in the high-score group than in the low-score group. The high-score group performed significantly better for grip strength (p=.0001, ηp 2 =.101), sit-ups (p=.0001, ηp 2 =.108), and VO2max (p=.0001, ηp 2 =.092) than the other two groups.[Conclusion] The present study suggests that bone-specific physical activity could be useful in improving body composition, BMD, and health-related physical fitness in middle-aged women, significantly enhancing their BMD and health conditions.

Background: To prevent adolescent obesity, recent research suggests that physical activity (PA), recreational screen-time, and sleep duration are codependent behaviours that being in a movement behaviour continuum in a 24-hour period. Yet, it is unknown about compliance with the 24-hour movement guidelines in Asian adolescents, and how these movement behaviours collectively affect overweight and obesity in adolescents. The purposes of this study were to compare compliance with the 24-movement guidelines in Asian adolescents, as well as to examine the association between meeting the 24-hour movement guidelines and body fat percentage. Methods: A sample of 12,590 adolescents aged 13.63 (± 1.01) years from eight Asian metropolitan cities including Bangkok (Thailand), Hong Kong SAR, Kuala Lumpur (Malaysia), Seoul (South Korea), Shanghai (China), Singapore, Taipei (Taiwan), and Tokyo (Japan) participated this study. The adolescents were asked to complete an interviewer-administered questionnaire to assess moderate-to-vigorous PA, recreational screen-time, sleep duration, and covariates. Adolescent’s body fat percentage was assessed using bioelectrical impedance analysis.Results: Findings show that a small proportion of Asian adolescents met the independent or combined guidelines of PA, recreational screen-time, and sleep duration. In addition, number of the guideline being met and combinations of the guidelines being met differed across the eight cities. Adjusting for covariates, we observed a negative association between number of the guidelines being met and body fat percent in Asian adolescents. In addition, meeting only the sleep duration guideline and both the physical activity and sleep duration guidelines had negative associations with body fat percentage compared with no guidelines being met.Conclusions: The current study was the first to evaluate compliance with the 24-hour movement guidelines in Asia-wide adolescents. Given only 1%-3% adolescents met all three movement guidelines, global strategies are needed to promote healthy lifestyles in adolescents. This study also provides primary evidence on the association between compliance with the 24-hour movement guidelines and adiposity in adolescents. Prospective follow-up studies are warranted to gain better insights into the compliance with 24-hour movement guidelines and the related health outcomes to contribute to the growth of evidence in this area.

This study examined the effects of high-impact weight-bearing exercise on bone mineral density (BMD) and bone metabolic markers in middle-aged premenopausal women. Forty middle-aged premenopausal women were initially enrolled, but thirty-one participants (40.34 ± 3.69 years) completed in the study. The subjects were randomly divided into two groups including the high-impact weight-bearing exercise group (HWE, n = 14) and control group (CON, n = 17). The HWE group participated in the exercise for 50 min a day, three days per week for four months, while the CON group maintained their regular lifestyle. The HWE program included 10 different high-impact weight-bearing exercises such as jumping and running. BMD was measured using DXA (Hologic, QDR 4500W, Marlborough, MA, USA). The bone metabolic markers including serum 25-(OH) D, intact parathyroid hormone (PTH), osteoprotegerin (OPG), osteopontin (OPN), receptor activator of nuclear factor κB ligand (RANKL), osteocalcin (OC), C-terminal telopeptide of type 1 collagen (CTX), and calcium were analyzed. The results showed that the BMDs of femur, lumbar, and forearm did not significantly change during the intervention period in both the HWE and CON groups. A significant decrease in bone formation markers such as OC (F = 10.514, p = 0.003, ηp2 = 0.266) and an increase in bone resorption marker including CTX (F = 8.768, p = 0.006, ηp2 = 0.232) were found only in the CON group, while these values did not change in the HWE group. There was a significant increase in serum 25-(OH) D (F = 4.451, p = 0.044, ηp2 = 0.133) in the HWE group. Our findings suggest that four months of HWE is not sufficient to improve BMD and bone metabolic markers, but this impact exercise program may prevent the age-associated changes in bone turnover markers in middle-aged premenopausal women.