Differences In Muscular Strength Research Articles

Analysis of the comparison between concentric and eccentric muscle strength in the bilateral knee joint of elite female volleyball players

<p>目的：本研究目的為探討優秀女子排球選手在雙側膝關節伸展與屈曲動作肌力與肌力平衡特徵之差異。方法：以等速肌力測量儀檢測參與者雙側膝關節之力矩，研究參與者為 16 名大專公開一級女子排球選手。統計分析以成對樣本t-tset比較女子排球選手在雙側膝關節伸屈肌力矩之差異及傳統式腿後肌與四頭肌比值 (hamstring to quadriceps strength ratio, H/Q 比值) 與功能性 H/Q 比值的差異，顯著水準訂為α ＝ .05。結果：排球選手在雙側膝關節的伸屈肌向心最大力矩中，只有在 60 °/s 時的伸肌未達顯著差異，其餘向心最大力矩皆有達顯著差異，且慣用側大於非慣用側；在雙側膝關節肌力之伸屈肌離心最大力矩與傳統式 H/Q 比值皆未達顯著差異，傳統式 H/Q 比值雖未達顯著差異，但都低於理想的安全值；在功能性比值方面，60 °/s 時伸、屈動作皆未達顯著差異，而 180 °/s 時伸展與屈曲動作則皆達到顯著差異，且非慣用側大於慣用側。結論：參與者應加強雙側的腿後肌群向心力矩，以提高傳統式 H/Q 比值，降低受傷的風險。功能性比值在伸展與屈曲動作的爆發力矩皆出現差異，這與排球攻擊動作落地時以非慣用側著地緩衝的特性有關。因此，應重視非慣用側的肌力訓練，以降低受傷的風險，更進一步提升選手攻擊的能力。</p> <p> </p><p>Purpose: The purpose of this study was to investigate the differences in muscular strength and muscle balance characteristics in bilateral knee joint flexion-extension movements of elite female volleyball players. Methods: The study utilized the isokinetic dynamometer to measure the torque of the knee joint in 16 collegiate division Ⅰ female volleyball players. Statistical analysis was us-ing paired sample t-tests to compare the differences in knee joint flexion-extension torque, tradi-tional H/Q ratio(hamstring to quadriceps strength ratio, H/Q ratio) and functional H/Q ratio be-tween the dominant and non-dominant sides, with a significance level set at α = .05. Results: The study found that in the concentric maximum torque of knee joint flexion-extension muscles, sig-nificant differences were observed at all angular velocities except for the extension muscle at 60°/s. The dominant side exhibited greater torque than the non-dominant side. However, there were no significant differences in eccentric maximum torque and traditional H/Q ratio of knee joint muscles. Although the traditional H/Q ratio did not show significant differences, it remained below the ideal safety value. Regarding functional H/Q ratio, there were no significant differences in both flexion and extension movements at 60°/s, while at 180°/s, significant differences were observed in both flexion and extension movements, with the non-dominant side exhibiting greater values than the dominant side. Conclusion: Participants should enhance the concentric force of the traditional H/Q ratio to reduce the risk of injury. Discrepancies in functional ratios are evident in the torque generated during extension and flexion movements, attributed to the characteristic landing pattern, which involves buffering on the non-dominant side during volleyball attacking actions. Therefore, prioritizing strength training on the non-dominant side is crucial to mitigate injury risks and further enhance athletes’ attacking capabilities.</p> <p> </p>

بعض اشكال القوة وعلاقتها بانجاز فعالية ركض(110) متر حواجز لدى اللاعبين الشباب

The development of sports achievements was discussed, and muscle strength is one of the most important factors that affect sports performance, as it helps runners to enable them to perform the necessary movements and improve the speed of movement. Therefore, muscular strength has a major role in enhancing the athletic performance of athletes, as the issue of runners possessing types of muscular strength gains importance and specificity in the training process. The researchers noticed that there is a difference between one runner and another in completing the 110-meter hurdles, and this is clearly evident through the results he obtains. This result fluctuates from one race to another, between positive and negative, and it may be one of the most important reasons for the difference in muscular strength. The research sample represents youth team players, and special measurements were used, not extracting results. The researchers concluded that there is a relationship between some types of strength with the completion of the 110-meter hurdles for young runners, and they recommended paying attention to the results that they showed. Study of each type of strength in achievement 110 meter hurdles for young runners.

Analysis of health-related, skill-related physical strength, and physique by blood pressure levels of Korean seniors.

In Korea, the prevalence rate of hypertension among people aged over 30 is on an upward trend, which increased from 26.2% in 2008 to 28.3% in 2018. This hovers above the global morbidity rate of hypertension. As hypertension is the cause of cerebrovascular or cardiovascular diseases, early treatment and management are critical. Also, while there has been numerous research conducted on exercise intervention, the number of studies done on hypertension and physical fitness falls far below. To identify the relationship between health and physical fitness depending on the blood pressure levels of Korean seniors, the physical fitness test results of the National Fitness Award 100 conducted in 2017 were used, and blood pressure level, physique, and physical fitness data of 17,110 elderly population aged above 65 were analyzed. IBM Statistics SPSS 25.0 was used to process the collected data. Due to the gender difference in blood pressure levels, physique, and physical strength, the analysis was conducted by each gender, and the analysis of variance (ANOVA) was performed to identify the differences in physique and physical strength depending on the blood pressure level. Also, Tukey's HDS test was conducted if such differences were found. All analyzes were tested at the significance level (α) of 0.05. As a result of comparing the physique factors by blood pressure level, only males showed a significant difference between groups in terms of height(p = .019), and higher blood pressure implied greater height. Also, for both genders, those with high blood pressure appeared to have greater body weight(p < .001), body fat percentage(p < .001), BMI(p < .001), waist circumference(p < .001), and waist-to-height ratio(p < .001),. In addition, as the result of comparing health-related physical strength and skill-related physical strength by blood pressure level, males showed a significant difference only in muscular strength(p = .026) and flexibility(p < .001), while females showed a significant difference between groups in terms of cardiovascular endurance(p < .001), muscular strength(p = .025), muscular endurance(p < .001), balance, and motor coordination except for flexibility. Holistically, males only showed a significant difference in muscular strength and flexibility while females appeared to have a significant difference between groups in all categories except flexibility, which can be considered that physical fitness factors influence the blood pressure of females more than males.

Coordinative Dance Programs: A Viable Option For Improving Physical Fitness Among Older Adults

PURPOSE: The use of LaBlast, low impact coordinative dance, has previously been used as an alternative exercise to increase strength and stamina in older adults. However, it is unknown if structured exercise yields superior results in comparison to unstructured exercise (i.e., aerobic or strength training). The purpose was to determine if there is a difference in muscular strength and endurance between older adults who practiced LaBlast and unstructured exercise. METHODS: Older adults, 50+ y/o, were recruited from a senior-serving fitness center. Prior to the study, each participant self-selected to join either a structured or unstructured exercise (i.e., dance vs non-dance) group. Physical function was assessed cross-sectionally through the chair stand, arm curl, back scratch, chair sit & reach, tandem leg stand, 8 foot up-and-go, foot-tapping and 2-min step tests. A one-way between subjects MANOVA was conducted to compare the effect of exercise on physical function. RESULTS: Participants (n = 29) were 69.78 ± 9.55 (range 51-92) years of age, who were 93.15% non-Hispanic white, and 97% female. The LaBlast (n = 13) and Non-dance (n = 16) groups were homogenous in demographic variables (p = 0.019). There was no significant difference in the demographic variables between groups (p = 0.19). A One-way MANOVA showed a statistically significant difference in muscular strength and endurance between exercise groups [Wilks’s λ = 0.28, F(12,16) = 3.37, p = 0.01, partial η2 = 0.71]. The LaBlast exercise group demonstrated significantly greater physical function for chair stand (15.38 ± 4.05), arm curl (21.38 ± 5.36), and 2-min step test (107.69 ± 19.57) (p < 0.001) than non-dancers. Participants who chose an unstructured exercise had statistically greater strength for the 8 foot-up-and-go assessment, 7.90 ± 3.04; p = 0.01. CONCLUSIONS: Findings suggest the use of LaBlast, which is a coordinative dance program, to be an effective exercise program for older adults. The study contributes novel evidence on structured and unstructured physical activities and their health benefits. These findings help advance the literature by informing physical activity recommendations for older adult populations. Further research is needed to determine the minimum duration for participating in a structured exercise to achieve health benefits.

Musculoskeletal Differences Between Healthy Postpartum Runners And Nulliparous Controls

PURPOSE: Running has become a popular form of exercise for women during and after pregnancy. A host of changes occur during pregnancy and childbirth that can affect running mechanics. Currently due to a lack of research in this area, peer reviewed clinical recommendations on how to safely return to running are non-existent. This could be the reason up to 84% of postpartum runners report pain when running. Due to the lack of research on pregnancy and childbirth related changes on the musculoskeletal system, the purpose of this study was to examine strength and range of motion differences between healthy postpartum female runners and nulliparous controls. METHODS: Participants were grouped into either a postpartum runner (PPR) or a control group. Manual muscle testing was performed at the hip, knee, and ankle using handhold dynamometry for both participant groups. Lower extremity flexibility and range of motion testing and hypermobility screens were performed. Data was averaged over three trials and then normalized to bodyweight (NBW). Independent sample t-tests were conducted using α = 0.05. RESULTS: 33 PPR’s (BMI 24.31 ± 4.33; < 36 months postpartum) and 30 BMI matched nulliparous women (BMI 23.10 N ± 3.80) participated. PPR’s had 10.9% greater strength on left ankle inversion than controls (PPR 0.10 N ± 0.04; control 0.08 N ± 0.03; p 0.04). PPR’s had less right hip internal rotation strength than their controls (PPR 0.11 N ± 3.80; control 0.08 N ± 0.04; p 0.03). CONCLUSION: These findings suggest there might be potential differences in muscular strength between PPR and their control. PPR should be evaluated individually for specific impairments in muscular strength, flexibility, and range of motion to adequately return to running. Future studies should combine musculoskeletal measures with data on kinematics and kinetics to further understand running after childbirth.

Sex differences in perceived discomfort during seated static posture holding

This study investigated how sex modifies postural discomfort perception during a sagittally-symmetric, seated static posture holding (SPH) task. Ten male and 10 female participants performed SPH and conducted subjective discomfort ratings in a total of 108 task conditions. A regression analysis found that the impacts of the body joint reactive moments on perceived discomfort were larger for the female group than the male whereas that of the shoulder joint angle was more pronounced for the male than the female. Also, some of the 108 task conditions were found to be more uncomfortable for the male group, while some others, for the female. The observed sex impacts are thought to be due to the sex differences in physical work capacities (muscular strength and joint flexibility). The results suggest that new posture analysis tools allowing sex-specific analyses are needed as they would improve the accuracy and precision of ergonomics posture analyses. Practitioner summary: This study empirically investigated how sex modifies postural discomfort perception during a seated posture holding (SPH) task. Sex was found to modify the impacts of joint reactive moments and the shoulder joint angle. The study results seem to reflect the sex differences in muscular strength and joint flexibility.

Effects of age and sex on association between toe muscular strength and vertical jump performance in adolescent populations.

Toe muscular strength plays an important role in enhancing athletic performance because the forefoot is the only part of the body touching the ground. In general, muscular strength increases with age throughout adolescence, and sex-related difference in muscular strength becomes evident during childhood and adolescence. However, toe muscular strength is known to be levelled off after late adolescence in both sexes. For adolescent populations, therefore, the association of toe muscular strength with physical performance might differ with age and/or sex. This study aimed to investigate differences in relationships between toe muscular strength and vertical jump performance across sex and age in adolescent populations. The maximum isometric strength of the toe muscles and vertical jump height (VJ) were assessed in 479 junior high school students (JH) aged 12-14 years (243 boys and 236 girls) and 465 high school students (HS) aged 15-18 years (265 boys and 200 girls). Two types of measurements were performed to evaluate the toe muscular strength: toe gripping strength (TGS) with the metatarsophalangeal joint in the plantar flexed position and toe push strength (TPS) with the metatarsophalangeal joint in the dorsiflexed position. TGS and TPS were normalized to body weight. Two-way ANOVA showed that TGS had significant main effects of sex (boys > girls) and age (HS > JH) while TPS only had a significant main effect of sex (boys > girls). When the effects of sex and age were separately analyzed, VJ was significantly correlated with TGS in JH girls, HS girls, and JH boys (r = 0.253-0.269, p < 0.05), but not in HS boys (r = 0.062, p = 0.3351). These results suggest that toe muscular strength is relatively weakly associated with vertical jump performance in adolescent boys and girls, but the association would not be established in high school boys.

Exercise Training in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis.

ObjectiveTo evaluate the effects and safety of exercise training, and to determine the most effective exercise intervention for people with Duchenne muscular dystrophy. Exercise training was compared with no training, placebo or alternative exercise training. Primary outcomes were functioning and health-related quality of life. Secondary outcomes were muscular strength, endurance and lung function.Data sourcesA systematic literature search was conducted in Medline, EMBASE, CINAHL, Cochrane Central, PEDro and Scopus.Study selection and data extractionScreening, data extraction, risk of bias and quality assessment were carried out. Risk of bias was assessed using the Cochrane Collaborations risk of bias tools. The certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation.Data synthesisTwelve studies with 282 participants were included. A narrative synthesis showed limited or no improvements in functioning compared with controls. Health-related quality of life was assessed in only one study. A meta-analysis showed a significant difference in muscular strength and endurance in favour of exercise training compared with no training and placebo. However, the certainty of evidence was very low.ConclusionExercise training may be beneficial in Duchenne muscular dystrophy, but the evidence remains uncertain. Further research is needed on exercise training to promote functioning and health-related quality of life in Duchenne muscular dystrophy.LAY ABSTRACTThe aim of this study was to examine the effects of all types of exercise training compared with no training, placebo or alternative exercise training programmes in people with Duchenne muscular dystrophy. The primary outcomes were functioning and health-related quality of life. Secondary outcomes were muscular strength and endurance. A further aim was to evaluate safety and, if possible, to find the most effective exercise training intervention. This review investigates existing research on this topic. The results have been systematically gathered and analysed, to give a broader view of what effect exercise training may have for people with Duchenne muscular dystrophy. The results suggest that exercise training preserves functioning, and benefits muscular strength and endurance. The study was not able to identify the best type of exercise training and prescriptions to use in Duchenne muscular dystrophy. The validity of the results was reduced by the low number of studies included, the low quality of the studies, and diversity in both the interventions and outcome measures used. The results should therefore be interpreted with caution.

Improvements in physical functionality in elderly patients with spinal deformity after corrective fusion surgery: a gait analysis.

Extensive corrective fusion surgery was performed on elderly patients with adult spinal deformity (ASD) to improve abnormal posture. Varying improvements in postoperative walking function were expected owing to differences in muscular strength and bone quality between patients in their 40s and those over 75 years of age. The purpose of this study was to compare preoperative and postoperative gait posture and physical functionality in elderly patients with ASD who underwent extensive corrective fusion to the thoracic spine. A prospectively maintained surgical database was reviewed for patients with ASD who underwent corrective fusion surgery (thoracic spine to pelvis) between 2011 and 2016. The cohort was divided into three age groups: nonelderly (40-64 years), young-old (65-74 years), and old-old (> 75 years). Patients underwent a 4-m walk test preoperatively and 2 years postoperatively to measure gait-trunk tilt angle and walking speed (meters per minute). Among 291 patients with ASD who underwent corrective fusion surgery, 56 patients (14 men and 42 women; mean age 68.8 years) were included. Mean preoperative gait-trunk tilt angle (12.9° vs 5.2°, p < 0.01) and walking speed (41.2 m/min vs 45.7 m/min, p < 0.01) significantly improved postoperatively. Intergroup analysis revealed that the mean preoperative gait-trunk tilt angles in the nonelderly (n = 13), young-old (n = 28), and old-old (n = 15) groups were 11.9°, 10.0°, and 19.3°, respectively; postoperatively, these improved to 4.5°, 4.5°, and 7.2°, respectively. Mean preoperative walking speeds of 47.9, 40.0, and 37.7 m/min improved to 52.4, 44.8, and 41.5 m/min postoperatively in the nonelderly, young-old, and old-old groups, respectively. There were no statistically significant differences in degree of improvement in gait-trunk tilt angle and walking speed among groups. Extensive corrective fusion surgery improved the postoperative walking posture of patients with ASD. Statistical analysis of gait measurements demonstrated intergroup equivalence, indicating comparable improvement in physical functionality in elderly and middle-aged patients after corrective fusion surgery.

Effect Of Longterm Resistance Training On Bone Mineral Density, Muscular Strength, And Balance In Cerebral Palsy

Cerebral Palsy (CP) is a non-progressive neurological disorder caused by lesions in the brain leading to musculoskeletal dysfunction and immobility. Physical deconditioning in individuals with CP appears to accelerate muscle atrophy and osteoporosis; thus, adults with CP are more prone to fall and fracture. Balance is also related to the higher risk of fall in the general public, and resistance training is known to improve bone mineral density (BMD), muscular strength, followed by balance. However, equivocal results were reported whether resistance training has a positive effect on BMD, muscular function and balance in CP population. PURPOSE: To determine the influence of long-term resistance training to BMD, muscular strength, and balance in adults with CP who have muscle atrophy and/or osteoporosis. METHODS: 26 adults with and without CP were tested before and after resistance training twice a week for one year. Dual-energy X-ray absorptiometry was used to measure local BMD at the lumbar spine, proximal femur, and radial/ulnar regions. Muscular strength (torque, work, and power) from the lower extremity was assessed at 90, 150, and 210 ⁰/sec using the Humac Norm Isokinetic Dynamometer. The handgrip dynamometer was used for maximal isometric contraction. Balance was measured from the Berg Balance Test, and limits of stability test using the Biodex Balance System. RESULTS: After one year of resistance training, the CP group showed a significant improvement in BMD compared to before training [BMD at femoral neck (0.63±0.08 pre vs. 0.88±0.04 post, g/cm2)]; however, they did not show statistical differences in muscular strength [extensor peak torque (27±9 pre vs. 32±10 post, ft-lbs), flexor peak torque (13±4 pre vs. 12±5 post, ft-lbs)], or balance on limit of stability test [e.g. overall score (32±7 pre vs. 31±6 post)]. However, after training, CP participants who exhibited greater BMD appeared to develop greater muscular strength followed by improved balance. CONCLUSION: These findings suggest that long- term resistance training significantly improved BMD in CP adults without a dramatic improvement in muscular strength or balance. In addition, BMD appeared to play a role in enhanced muscular strength and balance in adults with CP, specifically only those who significantly gained BMD after resistance training.

Effect of Resistance Training on Muscular Function and Functional Mobility in Adults with Cerebral Palsy

Cerebral Palsy (CP) is a non-progressive neurological disorder due to damage in the brain leading to musculoskeletal dysfunction and immobility. Physical deconditioning of individuals with CP appears to accelerate muscle atrophy and osteoporosis; thus, adults with CP are more prone to fall and fracture. The lower state of balance and functional mobility is also related to the higher risk of fall in the general public, and resistance training is known to improve overall muscular strength and functional mobility. However, equivocal results were reported whether resistance training has a positive effect on muscular function and balance in CP population. PURPOSE: To determine the influence of resistance training to muscular strength and balance in adults with CP who already developed muscle atrophy and osteoporosis. METHODS: Twenty adults with and without CP were recruited. Seven CP participants completed post-exercise experiments after performing resistance training twice a week for three months. Muscular strength (torque, work, and power) at 90, 150, and 210 0/sec were assessed in the leg using the Humac Norm Isokinetic Dynamometer. Functional mobility was assessed from the Berg Balance Test, and limits of stability test using the Biodex balance system. RESULTS: CP group had significantly lower knee extensor peak torque (e.g., 11.8±2.3 CP vs. 68±12.5 control, ft-lbs, P<0.05), and lower knee flexor peak torque (e.g., 6.3±1.6 CP vs. 43.8±7.9 control, ft-lbs, P<0.05) compared to control. After 3 months of training, CP group did not show statistical differences in muscular strength [e.g., extensor peak torque (27.5±17.0 pre vs. 31.5±24.2 post, ft-lbs, P>0.05), and flexor peak torque (9.3±5.6 pre, vs. 15.0±10.9 post, ft-lbs, P>0.05], or balance [e.g. overall score (25.2±16.1 pre vs. 24.3±11.4 post p>0.05) on limit of stability test, total score (18.0±19.5 pre vs. 24.4±21.6 p>0.05) on Berg Balance test. However, individuals who improved peak torque in knee flexors and extensors also improved postural stability via the Berg balance test. CONCLUSIONS: These preliminary findings suggest that muscular strength influences functional mobility in adults with CP only after exercise training.

A Growing Social Divide in Body Mass Index, Strength, and Fitness of Swedish Male Conscripts

PurposeThe aim of the study was to monitor trends in socioeconomic inequalities in body mass index (BMI), cardiorespiratory fitness (CRF), and muscular strength over several decades in a population of Swedish males aged 18–19 years. MethodsThe cohort consists of 1.5 million young men attending military conscript examinations from late 1968 to 2005. Parental education was used as a marker for socioeconomic conditions in the conscripts' families of origin. Changing gradient in BMI, CRF, and muscular strength in sons of parents with higher and lower educational attainment was evaluated during four periods covering 36 years. ResultsOver the course of the obesity epidemic, BMI remained higher in conscripts with lesser (vs. higher) parental education. Moreover, the absolute difference in obesity prevalence between groups showed a continuous increase, from .6% to 3.9%, indicating growing inequalities. Regarding fitness, lower CRF was consistently associated with less parental education, but with no clear secular trend in the magnitude of the difference. Finally, social differences in muscular strength changed in direction, from lower strength among conscripts with higher parental education in the initial observation period to lower strength associated with lower parental education in the final decade studied. ConclusionsAmong Swedish conscripts entering adulthood, social gradients in BMI and obesity widened continuously between 1968 and 2005. An apparent reversal of the earlier gradient in muscular strength in young men may be related to societal trends in occupational and leisure-time physical activity over the observation period. This cohort is being continually monitored through national registries for obesity-related comorbidities in later life.

Muscular strength and power are correlated with motor unit action potential amplitudes, but not myosin heavy chain isoforms in sedentary males and females

It remains unclear if the sizes of higher-threshold motor units (MU) are associated with muscular strength and power. Therefore, the purpose of this study was to examine sex-related differences in muscle cross-sectional area (mCSA), percent myosin heavy chain (%MHC) isoform expression, and the MU action potential amplitudes (MUAPAMPS)-recruitment threshold (RT) relationships of the vastus lateralis and isometric peak torque, isokinetic peak torque and mean power at 1.05 rad·s−1 of the leg extensors. Surface electromyographic decomposition techniques were used to quantify MUAPAMPS recorded during isometric muscle actions at 70% of maximal voluntary contractions and regressed against RTs with the slopes calculated. Ultrasound images were used to measure mCSA. Males had greater slopes from the MUAPAMP-RT relationship than the females (P < 0.05). The greater slopes likely reflected larger higher-threshold MUs for the males. The mCSAs and slopes from the relationships were strongly correlated with isometric and isokinetic peak torque and isokinetic mean power (r = 0.78–0.82), however, type I %MHC isoform was only moderately correlated with isometric peak torque (r = −0.54). The results indicated that sex-related differences in muscular strength and power were associated more so with the sizes of the higher-threshold MUs (slopes) and mCSA than MHC isoforms. The amount of cross-bridge activity within muscle fibers that comprise higher-threshold MUs may be the primary contributor to muscular strength and power rather than the contractile properties of the muscle.

The characteristic analysis of body composition and isokinetic leg strength in adult females

[Purpose] The purpose of this study was to provide the physiological characteristics of female adults in their 30s by comparing the body composition and the maximal strength of the knee extension and flexion and bilateral ratio and ipsilateral ratio(H/Q: Hamstring and Quadriceps ratio) depending on age. [Methods] Body composition was measured by Hv-ps 7681(GE medical systems Lunar, USA). Isokinetic lower limb muscular strength was measured by Isomed2000(D&amp;R Ferstl GMBH, Germany). 92 volunteers who were chosen by our selection criteria agreed to participate in our study. The participants were divided into three groups depending on age and classified as female adults in twenties(n=30), in thirties(n=34), in forties(n=28). To evaluate differences according to age, One-way ANOVA was used. [Results] The result in the test for female adults is as follows. In body composition, there were significant differences in lean mass, bone mineral density in the legs area among groups(p&lt;.05). In isokinetic test, there were significant differences in muscular strength among groups in extensor of knee(p&lt;.05). [Conclusion] The finding revealed that strength training based on the characteristics depending on age is required and ipsilateral ratio needs to be improved.

Effect of high-dose ginsenoside complex (UG0712) supplementation on physical performance of healthy adults during a 12-week supervised exercise program: A randomized placebo-controlled clinical trial

BackgroundGinseng has been used as an ergogenic agent, although evidence for its effectiveness is weak. A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effect of a ginsenoside complex (UG0712) on changes in exercise performance. MethodsSedentary individuals (n=117) were randomly assigned into one of three groups: low-dose ginsenoside supplementation (100 mg/d, n=39), high-dose ginsenoside supplementation (500 mg/d, n=39), or a placebo group (500 mg/d, n=39). All participants underwent a supervised 12-wk aerobic and resistance exercise training course. To assess the effects of supplementation on physical performance, maximal oxygen consumption (VO2max), anaerobic threshold (AT), lactic acid, and muscle strength of the dominant knee were measured at baseline, every visit, and after the training program. ResultsBoth ginsenoside groups showed significant increases in VO2max and muscular strength during exercise training. There were no definite changes in AT and lactic acid levels over time. After exercise training, there were definite differences in the VO2max (28.64.9 to 33.7±4.9 ml/kg/min in high-dose group vs. 30.4±6.7 to 32.8±6.6 ml/kg/min in placebo, p=0.029) and AT (19.3±4.2 to 20.9±3.5 ml/kg/min in high-dose group vs. 20.0±5.1 to 20.0±4.9 ml/kg/min in placebo, p=0.038) between the high-dose ginsenoside and placebo groups. However, there was no difference in VO2max between the low-dose ginsenoside and placebo groups (p=0.254). There were no differences in muscular strength during exercise training among the three groups. ConclusionHigh-dose ginsenoside supplementation (UG0712) augmented the improvement of aerobic capacity by exercise training.

Effects of 12 Weeks Combined Exercise on Physical Fitness, Irisin and BNDF in White-Collar Woman Workers

PURPOSE The purpose of this study is to examine on the effects of 12 weeks combined exercised on physical fitness, Irisin and BNDF in white-collar women workers who are sedentary lifestyles. METHODS In this study, there were controlled groups and exercise group: one was composed of women who had no regular exercise program and sedentary lifestyle (n=20), the other was made of white-collar women who had combined exercise, no muscular skeletal disease, same lifestyle (n=19), totally 39 women were participated in this study. Combined exercises were composed of aerobic exercise, resistance exercise, flexibility, and balance exercise: Conducting mid-level exercise with 65% VO2max consumption, 3 times a week, and 80 minutes for 12 weeks. For certifying the purpose of this study, calculate the average and standard deviation of every variant using descriptive statistics and apply analysis of covariance measures ANCOVA for interaction between groups. RESULTS In LBM and Body fat percentage, there was no significant difference after exercise. In other words, there was significant difference in body fat (p<.001). Physical fitness has some significant difference in muscular strength, muscular endurance, power, balance and flexibility (p<.001; p<.001; p<.05; p<.05; p<.001). But there was no significant difference in VO2max. There was no significant difference in BDNF and Irisin for groups after exercise. CONCLUSIONS Consequently, it shows that 12 weeks combined exercise made a positive effect on body composition, physical fitness in white-collar woman workers. 색인어: 사무직 여성, 복합운동, ì²´ë ¥, Irisin, BDNF Keywords: White-collar woman workers, Combined exercise, Physical fitness, Irisin, BDNF

Association between grip strength and diabetes prevalence in black, South-Asian, and white European ethnic groups: a cross-sectional analysis of 418656 participants in the UK Biobank study.

To quantify the extent to which ethnic differences in muscular strength might account for the substantially higher prevalence of diabetes in black and South-Asian compared with white European adults. This cross-sectional study used baseline data from the UK Biobank study on 418656 white European, black and South-Asian participants, aged 40-69years, who had complete data on diabetes status and hand-grip strength. Associations between hand-grip strength and diabetes were assessed using logistic regression and were adjusted for potential confounding factors. Lower grip strength was associated with higher prevalence of diabetes, independent of confounding factors, across all ethnicities in both men and women. Diabetes prevalence was approximately three- to fourfold higher in South-Asian and two- to threefold higher in black participants compared with white European participants across all levels of grip strength, but grip strength in South-Asian men and women was ~5-6kg lower than in the other ethnic groups. Thus, the attributable risk for diabetes associated with low grip strength was substantially higher in South-Asian participants (3.9 and 4.2 cases per 100 men and women, respectively) than in white participants (2.0 and 0.6 cases per 100 men and women, respectively). Attributable risk associated with low grip strength was also high in black men (4.3 cases) but not in black women (0.4 cases). Low strength is associated with a disproportionately large number of diabetes cases in South-Asian men and women and in black men. Trials are needed to determine whether interventions to improve strength in these groups could help reduce ethnic inequalities in diabetes prevalence.

A study on the physical fitness of children with juvenile rheumatoid arthritis

[Purpose] This study was conducted to assess the physical fitness of children with juvenile rheumatoid arthritis (JRA). [Subjects and Methods] In total, 26 children with juvenile rheumatoid arthritis (JRA) and 25 healthy controls participated in this study. Using the physical fitness measurement instruments, the Inbody 720 and Quark b2, the elements of physical fitness that were assessed included muscular strength, muscular endurance, flexibility, lung capacity, and body composition. [Results] The results revealed significant differences in muscular strength, muscular endurance, lung capacity, body composition, functional ability, and health-related quality of life between the children with juvenile rheumatoid arthritis (JRA) and the control group. [Conclusion] These results suggested that children with juvenile rheumatoid arthritis (JRA) have inferior physical fitness when compared to healthy children. The present study was conducted to develop an accurate evaluation standard to assess the physical fitness of children with juvenile rheumatoid arthritis (JRA).

Isokinetic dynamometry on the internal rotator and adductor muscles of the swimmers’ shoulders: no differences between asymmetrical and symmetrical swimming strokes

OBJECTIVE: In this study, we compare muscular strength of the internal rotators and adductors of the shoulder between asymmetrical (backstroke and freestyle) and symmetrical (breaststroke and butterfly) swimming strokes. METHOD: We evaluated: shoulders of (a) asymmetrical swimmers (aged 21.8 ± 3.8 years), (b) symmetrical swimmers (aged 20.3 ± 4.5 years), (c) recreational swimmers (aged 24.5 ± 4.5 years), and (d) control individuals (aged 25.8 ± 3.5 years). All evaluations were performed on a Biodex® isokinetic dynamometer at velocities of 60° and 300°/second. Adduction and internal rotation movements were evaluated. The variables studied were peak torque corrected for body weight (PTQ/BW), total work (TW) and the agonist/antagonist relationship. RESULTS: There were no differences in adductor strength between the symmetrical and asymmetrical swimmers regarding PTQ/BW (symmetrical: 114.4 Newto-meter vs. asymmetrical: 109.4 Newton-meter) and TW (symmetrical: 642.9 Joules; asymmetrical: 641.5 Joules). There was no difference in the abduction/adduction relationship between the symmetrical (67.4%) and asymmetrical (68.3%) swimmers. There was no difference in the internal rotator musculature between the symmetrical and asymmetrical swimmers regarding the variables PTQ/BW (symmetrical = 66.4 Newton-meter and asymmetrical = 63.4 Newton-meterm) and TW (symmetrical = 517.4 J and asymmetrical 526.7 J). There was no difference in the ratio of external to internal rotation of the shoulder between the symmetrical (65.7%) and asymmetrical (61.5%) swimmers. CONCLUSIONS: There were no differences in muscular strength in the adductor and internal rotator muscles of the shoulder between symmetrical and asymmetrical swimming strokes.

Isokinetic muscle strength differences in patients with mucopolysaccharidosis I, II, and VI.

To determine muscular strength differences in patients with MPS-I, II, and VI versus age- and sex-matched healthy controls. Dominant leg isokinetic knee extension strength was measured at 90 and 120 degrees per second (d/s) using a dynamometer in 30 subjects with MPS and 42 controls (5-16 yrs). MPS-I was further divided into MPS-IA (attenuated) and MPS-IH (severe). Strength measures analyzed were peak torque (PkT), peak torque per unit body weight (PkT/BW) and per unit lean body mass (PkT/LBM), and average power (AP). Following adjusting strength measures for age, MPS-IH and MPS-II had significantly lower strength measures for all variables at both angular velocities. MPS-VI had significantly lower PkT, PkT/LBM, and AP compared to controls at 90 and 120d/s. In contrast, MPS-IA was not significantly different from controls for any strength variable at either angular velocity. The results of this study suggest that decrements in skeletal muscle strength depend on MPS diagnosis and severity of disease. Children with MPS-IH demonstrate the greatest difference in muscular strength compared to healthy controls.