The purpose of this study was to find which percentage of 1RM for squat to improve the result of squat jump most effectively after plyometric training with different percentage of 1RM for squat. 24 men in their twenties were measured 1RM for squat and separated in 4 groups by 6 participants. Group A, B, C, and D used 0, 15, 30, and 45% of 1RM, respectively in the plyometric training. All groups had 1 hour training 3 days per week for 8 weeks(24 sessions). This study designed to increase the number of sets of exercises gradually. In week 1 and 2, participants trained 1 set of plyometrics with no load. The number of sets increased 2 to 4 in the week 3-4 to 7-8. The jump height(cm) and vertical impulse(%BW) of squat jump before and after plyometric training were measured by 3D motion capture system and force plate. All 4 groups showed the improvement of squat jump height and vertical impulse, but specially group B was most improved(p<0.5).
The human foot is only part that directly contact between the body and the external environment, and is ideally positioned to provide sensory information to the Central Nervous System (CNS) during static and dynamic tasks. Through cutaneous mechanoreceptors located in the dermis, the foot is able to recognize touch pressure and vibration stimuli, which provide important feedback information used for the fine coordination of movements. The purpose of this study is to quantitatively examine the effect of changing the foot cutaneous sensory by temperature stimulus on maximal performance and muscle activation using wavelet technique. Sixteen healthy subjects volunteered to participate in this study (Male: Age 21.4±2.4years; Height 174.7±5.3츠; Weight 70.6±5.2kg; Female: Age 20.5±0.6years; Height 163.2±3.1cm; Weight 55.6±4.8kg). Sensory pressure thresholds were determined for the plantar surface of the foot using monofilament. Kinematic, kinetic and EMG data which relative to maximal performance were collected while squat jumping in each temperature condition(cool 12-15℃ normal 28-30℃ hot 45-48℃). Maximal jump height was significant higher in normal condition. Vertical GRF in normal condition showed higher peak value the other conditions. And then EMG signal were significant different between temperature conditions during maximal performance. By changed sensory feedback on temperature, one can alter maximal performance and muscle activation pattern. Cutaneous feedback is important in performance and neuromuscular control, and temperature changes significantly influence on lower extremity during maximal squat jump performance of healthy subjects.
Purpose This study was conducted to analyze the differences of physical characteristics focused on the physique, strength, and power for cycling national athletes (Sprint cyclists and Road race cyclists). Methods We measured various factors (e.g., height, weight, body fat ratio, thigh circumference, waist circumference, anaerobic power, isokinetic muscular strength, muscle power, squat jump by 1RM intensity, and so on) for a total 11 male cycling national athletes (5 Sprint cyclists and 6 Road race cyclists). Results First, the body composition showed the significant differences only in weight (p=0.31) and BMI (p=.001) for Sprint cyclists. Second, the values of the anaerobic power for the Sprint cyclists were significantly higher than those for the Road race cyclists only at peak power (p=0.28), whereas there was no significant difference in average power, isokinetic muscular strength, and muscle power between the two groups. Third, the isokinetic trunk flexion muscle (p = .016) for the Sprint cyclists were significantly higher than those for the Road race cyclists. Fourth, the significant difference in Time to Peak Torque was not found between two groups. Fifth, the values for the Sprint cyclists showed the significant difference in all 5 intensity groups (0%, 30%, 50%, 60%, and 80%) (p=.001) of the squat jump. Also, there was a statistically significant difference only in 0% velocity between the two groups, except for exercise intensity. Conclusions From the various measures between two groups, the Sprint cyclists relatively showed the high weight, BMI (muscle mass), and maximum power. Additionally, the isokinetic trunk flexion muscle and the squat jump were higher in the Sprint cyclists than the Road race cyclists. These data may be used as basic data to improve the physical fitness factors related to the athletic performance of the athletes by reflecting them in the effective training plan and evaluation of the athletes.
Purpose The purpose of this study is to examine the differences in physique and physical fitness factors affecting exercise performance according to the vitamin D receptor (VDR) FokI gene polymorphism in athletic gifted children. Methods FokI VDR polymorphisms were genotyped in 82 boys (9.1±0.9 years) and 55 girls (9.3±0.9 years). Basic physical fitness (basketball throw, half-squat jump, standing long jump, 15m pacer, 50m run, handgrip strength, side-step, trunk forward flexion, sit-up) and physique were measured and analyzed using one-way ANOVA with bonferroni’s correction. Results No association was found between the VDR FokI genotypes and all the physical fitness variables as well as physique variables in boys and girl. However, Hardy-Weinberg equilibrium results for VDR polymorphism distribution showed significant differences (χ2= 6.516, df=2, p=.038). Conclusion Although there was no significant difference in the fitness variables according to the VDR Fok1 genotype, it was difficult to exclude the potential for predicting fitness in that the H-W equilibrium test showed a significant difference. Therefore, in order to confirm the true potential of the VDR Fok1 gene to predict physical fitness, it is considered that additional studies on general children should be conducted.
PURPOSE This study investigated the effects of 12 weeks of clubbell and stepbox training on physical fitness, badminton skills, and fatigue in male badminton, grade A (top grade) club members aged 20–30s, with over 5 years’ experience. METHODS Participants in a training group (TR: n=15) engaged in 12 weeks of clubbell and stepbox circuit training involving maximum 8–12 reps of clubbell exercises and stepbox exercises at over 77% of HRmax for 50–55 min/sessions three times a week. Participants in a control group (CON: n=15) maintained their normal lifestyle pattern during the same intervention period. Dependent variables were measured and compared using repeated measures two-way ANOVA. RESULTS The main results were as follows: 1) The groups showed no significant differences in body composition. 2) Regarding physical fitness, VO2max, relative peak power, relative average power, grip strength, push ups, repeated jump squats, SSPT (seated single-arm shot-put test), 10 m sprint, and hexagon agility increased significantly in the TR, while push ups decreased significantly in the CON. 3) As for badminton skills, forehand clear accuracy, badminton agility, badminton endurance, and smash speed increased significantly in the TR. Forehand clear accuracy decreased significantly in the CON, but badminton agility and smash speed increased significantly. 4) The groups showed no significant differences in fatigue. CONCLUSIONS In male badminton club members aged 20–30s, 12 weeks of clubbell and stepbox circuit training effectively improved physical fitness and badminton skills. However, lack of any improvement in body composition and fatigue warranted further research in these areas.
The purpose of this study was to investigate basal physical fitness and smash speed of elite national badminton players. To perform this study, total forty six korea national badminton player were participated : twenty two male players(age : 20.90±2.24years, height : 179.30±5.40cm, weight : 73.80±7.12kg, career : 11.27±1.88years) and twenty four female players(age : 19.45±1.95years, height : 167.83±4.36cm, weight : 61.39±3.60kg, career : 9.50±2.47years). Each subjects performed the 6 basal physical fitness trials : agility, muscular endurance, muscular strength, flexibility, balance and cardiorespiratory endurance. And the speed of badminton smash were analysis by using radar gun when players were standing smash success. To determine the difference between two groups, independent samples test was used. As a result, we found that there was a large difference male players and female players in basal physical fitness and smash speed. First, male players were significantly strong in agility(side step 10%), muscular endurance(repetitional jump 12%), muscular strength(left grasping power 3%, right grasping power 31%) and cardiorespiratory endurance(20m suttle run 31%). On the other hand, female players were relatively strong in flexibility(sit and reach 27%) and balance(standing on one leg with eyes closed 51%). Second, maximum smash speed show that male players were about 57km/h(24%) faster than female players(male : 247.72km/h, female : 190.37km/h). Based on the findings, we shall be applicable training program to improve flexibility, balance of male athletes and agility, muscular endurance, muscular strength, and cardiorespiratory endurance of female athletes. our results will be appliable to improve the athletic performances of national badminton players by the coaches in the future.
