PURPOSE This study investigated the impact of underweight and hand grip strength (HGS) levels on the risk of all-cause mortality in older adults. METHODS Data from the 2006 baseline and 2020 follow-up assessments of the Korean Longitudinal Study of Aging (KLoSA), involving 3,009 older Koreans (≥65 years) were used in the study. Participants were categorized based on body mass index (BMI) as underweight, normal, overweight, or obese and grouped according to the Asian Working Group Sarcopenia criteria into high or low HGS. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of all-cause mortality according to BMI and HGS categories. RESULTS During the 11.3±4.0 years follow-up period, 1,334 deaths from all causes occurred. The risk of death by BMI and HGS level was analyzed. The results showed that the risk of death in the overweight and high HGS group (HR=0.773, p=.016) was significantly lower than that in the normal weight & high HGS group (HR=1). In comparison, the risk of death in the underweight & low HGS group (HR=1.930, p<.001) and the normal weight & high HGS group (HR=1.225, p=.014) were significantly higher than normal weight & high HGS. However, the risk of death in the underweight and high HGS group showed no significant difference compared to the normal weight and high HGS group. CONCLUSIONS The current findings suggest that improving muscle strength through regular exercise may be important in preventing the risk of all-cause mortality due to being underweight.
The purpose of this study was to explore and confirm Kumi-kata related factors of muscle strength by performance level in Korea elite female judoists. In order to achieve this purpose, 14 elite female judoists participated to this study. The subjects were divided to two groups (World Class Group and Non-World Class Group) according to their world ranking level(by ranked 30th). The analysis factors were repeated grip strength, Kumi-kata specific pulling strength and isokinetic strength of trunk joint. The results were as follows: Firstly, World Class Group had significantly higher repeated grip strength as compared to non-world class group (p<.001). Secondly, World Class Group had significantly higher specific Kumi-kata pulling strength as compare to non-world class group (p<.05). Finally, The differences between the two groups for isokinetic strength of trunk joint were non-significant. The results of this study indicates that a strong relationship exist between Kumi-kata related specific muscle strength and performance level in korea elite female judoists.
Purpose The purpose of this study is to compare the maximal strength, isokinetic muscle function and anaerobic capacity according to the position of college and professional rugby players. Methods Subjects for this study were 54 athletes and randomly divided into 4 groups: the forwards group in college rugby players (FCRP, n = 10), backs group in college rugby players (BCRP, n = 16), forwards group in professional rugby players (FPRP, n = 16), and backs group in professional rugby players (BPRP, n = 12). Physical fitness was consisted of squat, bench press, bilateral grip strength. Isokinetic knee and trunk muscle functions were measured by Humac Norm device, and anaerobic pedaling power was analyzed by Wingate test. Significant differences between groups were determined with one-way repeated ANOVA. Results As the result of this study, there was no statistically significant difference between the absolute and relative values of the squat and bilateral grip strengths, but bench press was significantly higher in FPRP and BPRP compared to other groups. Isokinetic knee and trunk extensor and flexor muscle strength showed stronger in FPRP and BPRP than those in FCRP and BCRP. In addition, the anaerobic pedaling power was also the highest in FPRP and BPRP. Conclusions Our findings suggest important information that the college rugby players and forwards in professional rugby team should be given scientific training to improve their maximum strength, isokinetic strength and anaerobic power.
Purpose The purpose of this study were to assess physiological and biochemical characteristics in elderly women with osteosarcopenic obesity (OSO), and to analyze relationships among irisin, adipokines and bone metabolism markers. Methods 126 elderly women were selected and among them 10 women were classified into OSO group (76.9±5.2 yrs) and 14 women were classified as a NOSO group (72.9±5.6 yrs). Physique, body composition and bone mineral density were measured. Senior fitness tests were 30-s chair stand, 30-s arm curl, chair sit-and-reach, back scratch, 8-foot up-and-go, grip strength, and 2-min step test. Isokinetic muscle strength was measured by isokinetic dynamometer (Cybex 770, USA). Nutrition intake and physical activity were administered. Biochemical parameters including irisin, FNDC-5, leptin, adiponectin, CTx, 25(OH)D, osteocalcin, and PTH were measured. All data were analyzed by SAS 9.4. Independent t-test was applied to compare between OSO and NOSO groups. Multiple regression analysis was used. The level of significance was set at .05. Results The results of the study showed that there were significantly high for waist circumference, hip circumference, WHR, and BMI in OSO group compared to those of NOSO group. Higher results were also obtained for fat tissue and percent body fat but significantly low for lumbar bone mineral density. OSO group showed significant lower results for grip strength and 2-min step test compared to NOSO group. Peak torque, and relative peak torque at 60° were significantly lower for left and right knee flexion in OSO group. Protein intake was significantly low in OSO group, but no difference was obtained in level of physical activity between two groups. Irisin was significantly related to adiponectin, FNDC-5 and osteocalcin in explaining 35.2%, 81.5% and 92.1% of the variance, respectively. Conclusions This study shows that elderly women with OSO have higher results for physique and body composition parameters except body height. However, lower values were obtained for functional fitness, and isokinetic muscle strength. OSO may have more risks for metabolic syndrome, bone fractures, fall, lack of daily physical activity and limit of locomotion due to the imbalance of quadriceps and biceps femoris in non dominant leg. This study suggests that criteria and mechanism of OSO should be clarified by follow-up study.
Purpose The purpose of this study was to examine the relationship between the track records and physical abilities in elite cyclists(keirin). Methods Twenty three elite cyclists were measured height, weight, lower body circumference(thigh, calf, and ankle), basal physical abilities(grip/back muscle strength, 25m sprint, Sargent jump test, Burpee test, shuttle run test), one-repetition maximum(1RM) strength(back squat, bench press, leg curl, power clean, dead-lift, leg press), aerobic capacity(V̇O2max, METs, HRmax), and track records(200m and 500m). Stepwise multiple regression analyses were performed to investigate which physical abilities related to track records. Results A statistically significant relationship was found between 200m track records and 2 variables which were the thigh circumference and 1RM leg press(p<.05). Also, the thigh circumference and 1RM leg press were significantly related to 500m track records(p<.05). Conclusions The results showed that the thigh circumference and maximal strength were associated with the track records in elite cyclists(keirin).
Purpose The purpose of this study was to examine the relationship between performance factors and physical fitness in secondary school female biathlon athletes. Participants in this study were 14 female biathlon athletes. Methods All factors such as aerobic capacity(VO2max, %AT), wingate test(peak power, average power, fatigue index), isokinetic test(trunk, knee, hip, ankle), 1RM test(leg press, chest press, lat pull down), physical fitness(grip, knee and back muscle strength, sit & reach, power, agility) were tested. In order to analyze collected data, pearson product moment and multiple regression analysis were utilized. The results were summarized as follows : First, there was a significant correlation between aerobic. Results The results were summarized as follows : First, there was a significant correlation between aerobic capacity and three factors(standing broad jump, isokinetic test 60° right knee extension)(p<.01). There was a significant correlation between wingate test and four factors(isokinetic test 30° left ankle ever, 30° right ankle ever, 120° left ankle inver, leg press)(p<.10). Conclusion These results suggested new evidence that ankle strength is necessary for performance in female biathlon athletes.
Purpose The purpose of this study was to find out the physical characteristics of Wushu athletes by comparing the differences on the results of physical fitness between the male athletes of the Wushu national team Taolu and the Sanda group. Methods Measurement of basic and professional fitness based on muscle function, targeting 37 men Wushu national team players (24 taolu, 13 Sanda) in the selection and evaluation contests twice in 2018 and 2019. Body composition, isometric muscle strength, flexibility and equilibrium, anaerobic power, and isokinetic muscle strength. The fitness factors were divided into two groups, Taolu and Sanda. Results First, body fat rate of the Sanda athlete group was significantly lower than that of the taolu athlete group (p<.01). Second, in the isometric muscle strength category(back muscle strength, grip strength), the Sanda athlete group had higher muscle strength than Taolu athlete group, but there was a statistically significant difference only in the left grip strength (p<.01). Third, in terms of flexibility and equilibrium, the taolu players were significantly higher in all items(p<.001). Fourth, in the anaerobic power, the taolu athlete group had higher both the peak power and the mean power, and there were a significant differences(peak power: p<.01, mean power: p<.001). Fifth, isokinetic muscle strength was significantly higher in the right knee flexion of the taolu athlete group (p<.01), and lumbar extensor muscle was significantly higher in the Sanda athlete group (p<.05). Sixth, in the isokinetic strength ratio, the knee flexion ratio of the Sanda athlete group were significantly higher on the left and right knee flexion and extensor ratios (p<.05). In addition, in the lumbar flexor and extensor ratios, the group of Sanda athlete group were significantly higher on the lumbar extensor(p<.05). Seventh, there was no significant difference between two groups in isokinetic muscle power. Conclusions The results of this study can be used as basic data to improve the efficiency of technical and physical training through the analysis of the characteristics of Taolu and Sanda. The effectiveness of this training will help to improve the performance.
PURPOSE This study investigated the effect of non-linear periodization strength training on basic and professional fitness of national cross-country skiers. METHODS The body composition (height, weight, BMI, body fat %), basic physical strength (grip strength, lung capacity), anaerobic power (peak power, average power), graded exercise test (maximum heart rate, running time, VO2max, lactic acid), isokinetic strength (trunk strength), and 1RM (bench press, dead-lift, squat, shoulder press, leg curl, bicep curl, cable triceps extension) of nine national cross-country skiers (male: 5, female: 4) were measured. All analyses were performed using SPSS 25.0, Kruskal-Wallis H tests were applied to observe the changes by training methods. Mann-Whitney U tests were used as Post Hoc. RESULTS The results indicated that running time and VO2max post-test improved compared to that for the pre-test for graded exercise test. The lumbar extension strength of the post-test was higher than that for pre-test. There was no significant difference in other variables. CONCLUSIONS It is suggested that nonlinear periodization strength training can be expected to improve running time, VO2max, and trunk strength for cross-country athletes; however, it does not affect the overall changes.
PURPOSE The purpose of this study was to investigate whether foam roller, preexhaustion, and static stretching had any effect on isometric muscular endurance of the finger flexors and climbing performance in sport climbers. METHODS Nine sport climbers who were able to perform at a climbing difficulty of 5.11d, were included in this study. Warm-up exercise consisted of myofascial release, pre-exhaustion exercises, and static stretching. Grip and back strengths were measured for muscular strength, and isometric muscular endurance of the finger flexors was measured as the time spent hanging on each hold according to the angle of the elbow joint. Repeated measures of ANOVA were performed to confirm the difference in treatment, and a significant difference between groups was confirmed by contrast test. RESULTS Myofascial release, pre-exhaustion, and static stretching before climbing did not affect muscle strength. However, the static stretching exercise significantly decreased isometric muscle endurance of the finger flexor at 90° open hold, and the pre-exhaustion exercise significantly decreased the hanging time at 180° crimp and slope grips. There was no effect on climbing performance according to the type of warm-up exercise. CONCLUSIONS Our findings suggested that various warm-up exercises did not directly affect muscle strength, muscular endurance, and climbing performance in sport climbers. Thus, we suggest that future research on complex warm-up exercises considering climbing postures should be conducted.
Purpose This study examines the regional differences in fall-related physical fitness and fall experience characteristics between Korean and Japanese elderly people. Methods The study includes 176 elderly residents of Gifu(35 male, 73.5yrs; 141 female, 72.4yrs) and 147 residents of Ulsan(46 male, 75.6yrs; 101 female, 75.6yrs). One-legged stance, hand grip strength, knee extension strength, 10 m gait, timed up and go test, 30-s chair stand, sit and reach, and reaction time were measured to examine the fall-related physical fitness. A questionnaire survey was also conducted to investigate the characteristics of the fall experiences. Results The elderly in Ulsan experienced a lot of falls compared to those in Gifu. Many of the fallers in Ulsan have fallen forward due to tripping, and they have often fallen backwards by losing balance. In addition, 14% of them suffered a bone fractured. The one-legged stance, hand grip strength, 10m gait, timed up and go, 30-s chair stand, and reaction time of the elderly in Gifu were superior to those in Ulsan. Conclusion In order to reduce the fall rate through improvements to fall related physical fitness and the awareness of fall prevention, various professional fall prevention programs and policies should be proposed, and they should be implemented systematically for community living elderly people.
