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There are no studies that have simultaneously examined muscle strength of high- and low-level athletes in each of the two competitive styles in wrestling. The purpose of this study was to clarify the characteristics of muscle strength by style and level of competition in lightweight athletes specializing in freestyle (FS) and Greco-Roman style (GS) in wrestling. Thirty-seven male collegiate lightweight wrestlers (age, 20.3±1.2 years; height, 165.3±3.7 cm; weight, 63.6±2.9 kg; competition career, 12.7±3.7 years) participated in this study. Participants were divided into 4 groups as follows: high-level GS (HGS, n＝9), low-level GS (LGS, n＝8), high-level FS (HFS, n＝8), and low-level FS (LFS, n＝12) . Isometric and isokinetic muscle extension and flexion torque of elbow, knee, and trunk as muscle strength were measured by biodex system 4. The main results of this study showed that isometric and isokinetic (60, 180, and 300 deg/sec) elbow extension strength were higher in high-level athletes than in low-level athletes, regardless of competitive style (all P<0.05), and that HGS was higher than HFS and LGS in isometric knee flexion muscle strength (P＝0.001, P＝0.023, respectively), and that GS was higher than FS in isometric knee and trunk extension muscle strength (P＝0.029, P＝0.014, respectively) . The results of this study suggest the importance of upper extremity extensor strength in wrestling competitions and the need for strength improvement programs based on competition style. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the relationship between the the physical ability of female collegiate badminton players and their shot skills. The subjects were female collegiate badminton players with similar athletic careers (around 10 years)．First, to clarify the athletic ability of the athletes, a round robin tournament was held to rank the participants (ranking points were given) and the relationship between the results and their shot skills that are frequently used in competitions, was analized. Then next, we investigated the relationship between shot skills and their physical abilities (muscular functional strength, anaerobic and aerobic capacity) which included their abilities to move on the court. The results are as follows: 1. There were positive correlation between ranking points and shot skill points (for clears and smashes)． 2. There were high correlation between ranking points and 6-direction footwork agility test, 30 times repeated shuttle, and total work of isokinetic knee joint extensor muscular strength. 3. There were high correlation between shot skill points especially in smash and mean anaerobic power output, 6-direction footwork agility test, 30 times repeated shuttle, and total work of isokinetic knee joint extensor muscular strength. The above results suggests that improving both the clear and the smash shot skills, improving aerobic capacity on the on-court by doing a 30 times repeated shuttle, improving lower limbs extensor strength and maintaining anaerobic power output may lead to a high level of smash shot skills that can be the key to deciding matches. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effects of low bone mineral density (BMD) risk factors and vitamin D receptor (VDR) and estrogen receptor alpha (ERα) gene polymorphisms on annual changes in BMD in collegiate female athletes. Participants were 239 female athletes belonging to a physical education university and were monitored about menstruation and injury for one year. A total of 173 participants (72.4％) were included in the statistical analysis because they completed all data. Total body, lumbar spine, and femoral neck BMD was measured by dual-energy X-ray absorptiometry at start of the experiment and one year later. VDR gene ApaI (rs7975232), TaqI (rs731236), and FokI (rs2228570) and ERα gene PvuII (rs2234693) and XbaI (rs9340799) polymorphisms were analyzed by TaqMan probe method. Multiple regression analysis performed for independent variables as BMI, menstrual cycle, stress fracture, sports type, and gene polymorphism and dependent variables as annual changes in each BMD site. Multiple regression analysis revealed that menstrual cycle and sports type were robust independent variables for lumbar spine and femoral neck BMD, respectively (β=- 0.161, P=0.034; β=- 0.184, P=0.016, respectively). These indicated that participants with amenorrhea were significant reduced lumbar spine BMD ( - 1.9％), and participation in endurance, aquatic, and esthetic type sports were significant reduced femoral neck BMD ( - 1.8％). In contrast, there were no significant differences in annual changes in BMD between any gene polymorphism and there were no interactions between low BMD risk factors and any gene polymorphisms. It suggests that annual changes in BMD in college female athletes may be reduced by amenorrhea and participating in endurance, aquatic and esthetic type sports, and may be unaffected by VDR gene ApaI, TaqI, and FokI and also ERα gene PvuII and XbaI polymorphisms in collegiate female athletes. [ABSTRACT FROM AUTHOR]