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1.
Abstract

Alpha-actinin-3 (ACTN3) is absent in 18% of healthy Caucasian individuals owing to homozygosity for a premature stop codon (X) at amino acid 577 (rs1815739). Previous studies have shown a strong association between ACTN3 genotype and human athletic performance. In a study of 452 young Chinese male soldiers, we examined the distribution of ACTN3 genotypes and alleles and analysed the association between ACTN3 genotypes and athletic performance. We found that the frequencies of the ACTN3 R577X genotype (RR 39.8%, RX 43.4%, and XX 16.8%) and R577X allele (R 61.5%, X 38.5%) in young Chinese males were not significantly different from those in Caucasians. We only observed a significant association (P = 0.025) between ACTN3 R577X genotypes and grip strength. Participants with the XX genotype displayed significantly lower handgrip strength than individuals with the RR genotype (P = 0.021), but the difference between XX and RX means (P = 0.258) and that between RR and RX means (P = 0.42) was not significant. We did not observe a strong association between the ACTN3 R577X genotypes and sprint phenotypes or endurance phenotypes. In conclusion, our results indicate that the ACTN3 R577X polymorphism is most strongly associated with grip strength in young Chinese male soldiers.  相似文献   

2.
Alpha-actinin-3 (ACTN3) is absent in 18% of healthy Caucasian individuals owing to homozygosity for a premature stop codon (X) at amino acid 577 (rs1815739). Previous studies have shown a strong association between ACTN3 genotype and human athletic performance. In a study of 452 young Chinese male soldiers, we examined the distribution of ACTN3 genotypes and alleles and analysed the association between ACTN3 genotypes and athletic performance. We found that the frequencies of the ACTN3 R577X genotype (RR 39.8%, RX 43.4%, and XX 16.8%) and R577X allele (R 61.5%, X 38.5%) in young Chinese males were not significantly different from those in Caucasians. We only observed a significant association (P = 0.025) between ACTN3 R577X genotypes and grip strength. Participants with the XX genotype displayed significantly lower handgrip strength than individuals with the RR genotype (P = 0.021), but the difference between XX and RX means (P = 0.258) and that between RR and RX means (P = 0.42) was not significant. We did not observe a strong association between the ACTN3 R577X genotypes and sprint phenotypes or endurance phenotypes. In conclusion, our results indicate that the ACTN3 R577X polymorphism is most strongly associated with grip strength in young Chinese male soldiers.  相似文献   

3.
Aim: Recent meta-analyses of the literature confirmed the association between the RR+RX genotype of the ACTN3 R577X polymorphism and elite sprint/power athletic status in Europeans but not in Asians and Africans, while the association between the R577X genotype and elite endurance athlete status is less convincing. The aim of the present study was to investigate the association between the ACTN3 R577X genotype and elite athlete status in a large Asian (Japanese) cohort of track and field athletes. Methods: One-thousand fifty-seven Japanese track and field athletes (627 sprint/power athletes and 430 endurance athletes) and 810 Japanese controls were genotyped for the ACTN3 R577X polymorphism (rs1815739) by using the TaqMan® SNP Genotyping Assay. Results: Elite sprint/power athletes had a higher frequency of the RR+RX genotype than the controls (OR: 1.59, 95% CI: 1.16–2.18; P?=?.003). A significant linear correlation was found between the RR?+?RX genotype and athlete status (i.e. regional?P?=?.001 for trend) and long-distance runners (regional: 65%, national: 72%, international: 82%; P?=?.030 for trend). Conclusions: The data obtained for this large Asian (Japanese) cohort of track and field athletes served to confirm the association between the RR?+?RX genotype of the ACTN3 R577X polymorphism and elite sprint/power athlete status and also the association between the ACTN3 RR?+?RX genotype and long-distance running athletic status.  相似文献   

4.
目的：探讨ACTN3 R577X多态性与青少年运动员爆发力素质及其表型指标的关联性，并检验ACTN3 R577X作为分子标记在青少年运动员科学选材中应用的可行性。方法：选取上海地区青少年业余体校青少年运动员96名，其中男运动员58名，女运动员38名，根据项目特点分为爆发力组和耐力组；利用SNaPshot SNP分型技术对采集的DNA样本进行基因分型。爆发力组运动员进行立定跳远、原地纵跳指标的测试。结果：青少年爆发力组运动员ACTN3 R577X基因型分布与青少年耐力组运动员(x2=7.289，P<0.05)和对照组人群(x2=6.831，P<0.05)均存在显著性差异；青少年爆发力组运动员的ACTN3 R577X等位基因频率与青少年耐力组运动员(x2=7.498，P<0.01)和对照组人群(x2=7.923，P<0.01)均存在显著性差异。在青少年爆发力组男、女运动员中，RR、RX基因型运动员的立定跳远和原地纵跳成绩都要显著性高于XX基因型的运动员（P<0.05，P<0.01）。结论 ACTN3基因 R577X多态性与上海地区青少年运动员爆发力素质存在关联，ACTN3基因 R577X多态性与立定跳远、原地纵跳等爆发力素质表型指标存在关联，ACTN3 基因R577X多态性可以作为青少年速度力量型运动员选材的分子标记。  相似文献   

5.
Ankle sprains are one of the most severe musculoskeletal soft tissue injuries during physical activity. Although many risk factors have been offered, it is unclear why some individuals develop noncontact ankle sprains when participating in comparable levels of physical exertion under identical environmental conditions and others do not. The ACTN3 gene that encodes the α-actinin-3 protein, which is, only expressed in the Z line of fast glycolytic muscle fibres was found to associate with power/strength performance. The aim of this study was therefore to investigate whether the ACTN3 gene polymorphism is associated with noncontact acute ankle sprains. One hundred and forty-two participants with clinically diagnosed noncontact acute ankle sprains as well as 280 physically active controls participants without any history of ankle sprains were included in this case–control genetic association study. The RR genotype (odds ratio (OR) = 0.56; 95% confidence interval (CI), 0.32–0.65, P = 0.011) and R allele (OR = 0.64; 95% CI, 0.37–0.68, P = 0.002) of the ACTN3 were significantly low-represented in the acute ankle sprains group compared with the control group. The ACTN3 R577X is associated with acute ankle sprains in Chinese participants in this study. This is the first study to suggest that an individual with a RR genotype is at a decreased risk of acute ankle sprains.  相似文献   

6.
Abstract

Incidence of vitamin D deficiency is increasing worldwide. The purpose of this study was to determine if supplementation with vitamin D2 from Portobello mushroom powder would enhance skeletal muscle function and attenuate exercise-induced muscle damage in low vitamin D status high school athletes. Participants were randomised to Portobello mushroom powder (600 IU/d vitamin D2) or placebo for 6 weeks. Participants then completed a 1.5-h exercise session designed to induce skeletal muscle damage. Blood samples and measures of skeletal muscle function were taken pre-supplementation, post-supplementation/pre-exercise and post-exercise. Six weeks supplementation with vitamin D2 increased serum 25(OH)D2 by 9.9-fold and decreased serum 25(OH)D3 by 28%. Changes in skeletal muscle function and circulating markers of skeletal muscle damage did not differ between groups. In conclusion, 600 IU/d vitamin D2 increased 25(OH)D2 with a concomitant decrease in 25(OD)D3, with no effect on muscular function or exercise-induced muscle damage in high school athletes.  相似文献   

7.
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8.
Abstract

The mechanisms of action of physical agents commonly used to treat skeletal muscle lesions are not well understood. In this study, we examined whether the modulation of oxidative stress is involved in the beneficial effects of cold and heat on gastrocnemius muscle strain injury. Adult male Wistar rats were submitted to a strain injury and treated with therapeutic agents in an isolated or combined form. Strain damage caused an increase in muscle and blood oxidative damage. We suggest that this oxidative damage might be related to the impairment of the muscle cell structure, since we observed a significant positive correlation between increased plasma creatine kinase activity and both oxidized dichlorofluoresceine and lipid peroxidation levels in muscle and blood. The intensity of the inflammatory response appears also to be an important factor in the genesis of oxidative damage immediately following a muscle strain injury. Therapeutic cold seems to be more effective in preventing the damage induced by a strain injury, possibly due to its capacity to control the impairment of muscle cell structure and to modulate the intensity of the inflammatory response that follows a muscle strain injury.  相似文献   

9.
BackgroundDuring human locomotion, a sufficiently stiff foot allows the ankle plantar flexors to generate large propulsive powers. Increasing foot stiffness (e.g., via a carbon plate) increases the ankle's external moment arm in relation to the internal moment arm (i.e., increasing gear ratio), reduces plantar flexor muscles’ shortening velocity, and enhances muscle force production. In contrast, when activation of the foot's intrinsic muscles is impaired, there is a reduction in foot and ankle work and metatarsophalangeal joint stiffness. We speculated that the reduced capacity to actively control metatarsophalangeal joint stiffness may impair the gearing function of the foot at the ankle.MethodsWe used a tibial nerve block to examine the direct effects of the intrinsic foot muscles on ankle joint kinetics, in vivo medial gastrocnemius’ musculotendinous dynamics, and ankle gear ratio on 14 participants during maximal vertical jumping.ResultsUnder the nerve block, the internal ankle plantar flexion moment decreased (p = 0.004) alongside a reduction in external moment arm length (p = 0.021) and ankle joint gear ratio (p = 0.049) when compared to the non-blocked condition. Although medial gastrocnemius muscle–tendon unit and fascicle velocity were not different between conditions, the Achilles tendon was shorter during propulsion in the nerve block condition (p < 0.001).ConclusionIn addition to their known role of regulating the energetic function of the foot, our data indicate that the intrinsic foot muscles also act to optimize ankle joint torque production and leverage during the propulsion phase of vertical jumping.  相似文献   

10.
The purpose of this study was to verify the association between ACTN3 polymorphism and physiological parameters related to endurance performance. A total of 150 healthy male volunteers performed a maximal incremental running test to determine the speeds corresponding to ventilatory threshold (VT) and respiratory compensation point (RCP). Participants were genotyped and divided into terciles based on the analysed variables. Genotype frequencies were compared through χ2 test between lower and higher terciles, with the lowest or highest values of each analysed variable. ACTN3 XX genotype was over-represented in higher tercile for VT and RCP. Odds ratio also showed significantly higher chances of XX individuals to be in higher tercile compared to RR (7.3) and RR + RX (3.5) for VT and compared to RR genotype (8.1) and RR + RX (3.4) for RCP. Thus, XX individuals could attain the VT and RCP at higher speeds, suggesting that they are able to sustain higher running speeds in lower exercise intensity domains. It could result in higher lipid acids oxidation, saving muscle glycogen and delaying the fatigue during prolonged exercises, which could be the advantage mechanism of this genotype to endurance performance.  相似文献   

11.
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12.
BackgroundFemales are typically less fatigable than males during sustained isometric contractions at lower isometric contraction intensities. This sex difference in fatigability becomes more variable during higher intensity isometric and dynamic contractions. While less fatiguing than isometric or concentric contractions, eccentric contractions induce greater and longer lasting impairments in force production. However, it is not clear how muscle weakness influences fatigability in males and females during sustained isometric contractions.MethodsWe investigated the effects of eccentric exercise-induced muscle weakness on time to task failure (TTF) during a sustained submaximal isometric contraction in young (18–30 years) healthy males (n = 9) and females (n = 10). Participants performed a sustained isometric contraction of the dorsiflexors at 35° plantar flexion by matching a 30% maximal voluntary contraction (MVC) torque target until task failure (i.e., falling below 5% of their target torque for ≥2 s). The same sustained isometric contraction was repeated 30 min after 150 maximal eccentric contractions. Agonist and antagonist activation were assessed using surface electromyography over the tibialis anterior and soleus muscles, respectively.ResultsMales were ∼41% stronger than females. Following eccentric exercise both males and females experienced an ∼20% decline in maximal voluntary contraction torque. TTF was ∼34% longer in females than males prior to eccentric exercise-induced muscle weakness. However, following eccentric exercise-induced muscle weakness, this sex-related difference was abolished, with both groups having an ∼45% shorter TTF. Notably, there was ∼100% greater antagonist activation in the female group during the sustained isometric contraction following exercise-induced weakness as compared to the males.ConclusionThis increase in antagonist activation disadvantaged females by decreasing their TTF, resulting in a blunting of their typical fatigability advantage over males.  相似文献   

13.
Abstract

Poor neuromuscular control and fatigue have been proposed as a risk factor for non-contact injuries especially around peak height velocity (PHV). This study explored the effects of competitive soccer match-play on neuromuscular performance and muscle damage in male youth soccer players. 24 youth players aged 13-16y were split into a PHV group (?0.5 to 0.5y) and post PHV group (1.0–2.5y) based on maturity off-set. Leg stiffness, reactive strength index (RSI), muscle activation, creatine kinase (CK), and muscle soreness were determined pre and post a competitive soccer match. Paired t-tests were used to explore differences pre and post competitive match play and independent sample t-tests for between groups differences for all outcome measures. There was no significant fatigue-related change in absolute and relative leg stiffness or muscle activation in both groups, except for the gastrocnemius in the post PHV group. RSI, CK and perceived muscle soreness were significantly different after soccer match-play in both groups with small to large effects observed (ES:0.41–2.82). There were no significant differences between the groups pre match-play except for absolute and relative leg stiffness (P?<?0.001; ES?=?1.16 and 0.63 respectively). No significant differences were observed in the fatigue related responses to competitive match play between groups except for perceived muscle soreness. The influence of competitive match-play on neuromuscular function and muscle damage is similar in male youth around the time of PHV and those post-PHV indicating that other factors must contribute to the heightened injury risk around PHV.  相似文献   

14.
Abstract

This study investigated symptoms of exercise-induced muscle damage following a simulated rugby league game. Ten male participants were assessed before, immediately after (0 h), and 24 and 48 h after the simulated game. Perceived muscle soreness was higher at all time points (P=0.001) and creatine kinase values were increased at 24 h following the simulated game (P=0.001). Peak knee extensor torque at 60 deg · s?1 was reduced up to 48 h (P =0.04) but was unchanged at 240 deg · s?1. Similarly, peak knee flexor torque at 60 deg · s?1 was lower than baseline up to 24 h, while at 240 deg · s?1 it was reduced at 24 h only (P=0.045). Correlations between changes in strength loss of the knee extensors and fat mass to fat-free mass ratio reveleaved no significant relationship between variables (P >0.05). In addition, countermovement jump performance was reduced at 0 and 24 h following the simulated game (P=0.008). Our results suggest that symptoms of exercise-induced muscle damage occur up to 48 h following a simulated rugby league match. Coaches should be cognisant of the large increases in muscle soreness and reductions in slow velocity force generation, and should adapt training accordingly in the 48 h period following a game.  相似文献   

15.
Abstract

Interleukin-6 (IL-6) is a multifunctional cytokine that exerts its modulatory effects on cells that express membrane bound IL-6 receptors; however, IL-6 in a complex with soluble IL-6R can bind to any cell that express glycoprotein 130 (gp130). Thus, all cell types may respond to the pro- as well as anti-inflammatory properties of IL-6. Since the first report of acute exercise-induced increase in plasma IL-6 in the early 1990s, scientists have tried to elucidate the factors that influence the magnitude of change of plasma IL-6, as well as the possible biological roles of this cytokine. Evidence suggests that exercise intensity and duration as well as the form of contraction (e.g. eccentric or concentric) and muscle damage all influence IL-6 response to acute exercise. However, data on training status and performance on plasma IL-6 concentration changes during exercise are more inconclusive, as discussed in this review. In the last decade, most of the studies have focused on IL-6 as an ‘energy sensor’ possibly secreted by skeletal muscle that activates glycogenolysis in the liver and lipolysis in fat tissue in order to provide muscle with the growing energy demands during exercise.  相似文献   

16.
BackgroundAngiogenesis constitutes a major mechanism responsible for exercise-induced beneficial effects. Our previous study identified a cluster of differentially expressed extracellular vesicle microRNAs (miRNAs) after exercise and found that some of them act as exerkines. However, whether these extracellular vesicle miRNAs mediate the exercise-induced angiogenesis remains unknown.MethodsA 9-day treadmill training was used as an exercise model in C57BL/6 mice. Liver-specific adeno-associated virus 8 was used to knock down microRNA-122-5p (miR-122-5p). Human umbilical vein endothelial cells were used in vitro.ResultsAmong these differentially expressed extracellular vesicle miRNAs, miR-122-5p was identified as a potent pro-angiogenic factor that activated vascular endothelial growth factor signaling and promoted angiogenesis both in vivo and in vitro. Exercise increased circulating levels of miR-122-5p, which was produced mainly by the liver and shuttled by extracellular vesicles in mice. Inhibition of circulating miR-122-5p or liver-specific knockdown of miR-122-5p significantly abolished the exercise-induced pro-angiogenic effect in skeletal muscles, and exercise-improved muscle performance in mice. Mechanistically, miR-122-5p promoted angiogenesis through shifting substrate preference to fatty acids in endothelial cells, and miR-122-5p upregulated endothelial cell fatty-acid utilization by targeting 1-acyl-sn-glycerol-3-phosphate acyltransferase (AGPAT1). In addition, miR-122-5p increased capillary density in perilesional skin tissues and accelerated wound healing in mice.ConclusionThese findings demonstrated that exercise promotes angiogenesis through upregulation of liver-derived extracellular vesicle miR-122-5p, which enhances fatty acid utilization by targeting AGPAT1 in endothelial cells, highlighting the therapeutic potential of miR-122-5p in tissue repair.  相似文献   

17.
Abstract

Research concerned with predictors of talent in football has highlighted a number of potentially important and partially inherited measures such as body size, anaerobic power, aerobic capacity, agility, psychological profile, game intelligence and susceptibility to injuries. Genotyping for performance-associated DNA polymorphisms at an early age could be useful in predicting later success in football. The aim of the study was to investigate individually and in combination the association of common gene polymorphisms with football player’s status. A total of 246 Russian football players and 872 controls were genotyped for 8 gene polymorphisms, which were previously reported to be associated with athlete status. Four alleles (ACE D, ACTN3 Arg577, PPARA rs4253778 C and UCP2 55Val) were first identified, showing discrete associations with football player’s status. Next, we determined the total genotype score (TGS, from the accumulated combination of the 4 polymorphisms, with a maximum value of 100 for the theoretically optimal polygenic score) in athletes and controls. The mean TGS was significantly higher in football players (52.0 (17.6) vs. 41.3 (15.5); P < 0.0001) than in controls. These data suggest that the likelihood of becoming a football player depends on the carriage of a high number of “favourable” gene variants.  相似文献   

18.
BackgroundExercise-associated menstrual dysfunction (EAMD) is a common health problem in female athletes as a part of female athlete triad (FAT), a condition related to low energy availability. In this study, we explored the possibility that carbohydrate supplements can improve the status of EAMD and prevent exercise-induced ovarian injury in a FAT rat model. This research aimed to provide experimental evidence with regard to the relationship of energy intervention and EAMD.MethodsForty-five female Sprague–Dawley rats (2 months old) were randomly divided into five experimental groups: control group (C), 9-week exercise as model for EAMD (E), post-EAMD recovery group (R), oligosaccharide intervention group (O), and glucose intervention group (G). All rats were sacrificed at the end of 9 weeks. Serum samples were collected for measuring gonadotropin releasing hormone, follicle stimulating hormone, luteinizing hormone, 17β-estradiol and progesterone levels. The ovaries were taken for investigation of exercise- and carbohydrate-induced follicular subcellular structure changes.ResultsExercise induced irregular menstrual cycles and ovary subcellular structural damages, such as swollenness of mitochondria in rats from groups E and R. Both glucose and oligosaccharide supplements restored well-differentiated mitochondria in the ovarian follicular cells, and a significant improvement of endoplasmic reticulum and Golgi in swollenness in theca cells in groups O and G compared to groups C, E, and R. There was no difference in mitochondria subcellular structural changes between groups O and G. Group E showed attenuation of serum levels of 17β-estradiol and progesterone compared to C. There were no differences of 17β-estradiol serum levels among groups O, G, and R, while group G showed a lower level of progesterone than C.ConclusionFemale adult rats with 9-week continuous exercise can cause menstrual dysregulation as a model for EAMD. Post-EAMD intervention with glucose and oligosaccharide intake can normalize the menstrual cycle, restore the follicular subcellular structure, and reverse the exercise-induced reduction of ovary sex hormones. It suggests a positive feedback of hypothalamus–pituitary–ovary axis might be involved in the molecular mechanisms of energy intake in treating EAMD.  相似文献   

19.
BackgroundPhysical activity (PA) in the early years is associated with a range of positive health outcomes. Fundamental motor skill (FMS) competence is associated with PA and is theorized to be driven by PA in the early years and vice versa in mid to late childhood. However, to date, no studies have meta-analyzed the association between PA and FMS in the early years.MethodsSix electronic databases were searched for articles published up to April 2019. Cross-sectional and longitudinal studies were included if they targeted children (ages 3–6 year) as the population of the study and assessed the association between objectively measured PA and FMS. Total FMS, total physical activity (TPA), and moderate-to-vigorous physical activity (MVPA) data were meta-analyzed using a random effects model.ResultsWe identified 24,815 titles and abstracts. In total, 19 studies met the inclusion criteria, including 14 cross-sectional and 4 longitudinal studies, as well as 1 study with cross-sectional and longitudinal analysis. There was a significant but small positive association between FMS and MVPA (r = 0.20, 95% confidence interval (CI): 0.13–0.26) and TPA (r = 0.20, 95%CI: 0.12–0.28). Findings from longitudinal studies revealed that PA drives FMS in early childhood. Mediation was explored in 1 study, which found that perceived motor competence did not mediate the association between FMS and PA.ConclusionUsing a meta-analysis, this study is the first to show a positive association between FMS, MVPA, and TPA in the early years of childhood, suggesting that the association begins at an early age. Limited evidence from longitudinal studies supports the theory that PA drives FMS in the early years of childhood. More evidence is needed from large studies to track PA and FMS until mid to late childhood and to explore the mediators of this association.  相似文献   

20.
BackgroundThis study presents a kinematic analysis of an acute lateral ankle sprain incurred during a televised badminton match. The kinematics of this injury were compared to those of 19 previously reported cases in the published literature.MethodsFour camera views of an acute lateral ankle sprain incurred during a televised badminton match were synchronized and rendered in 3-dimensional animation software. A badminton court with known dimensions was built in a virtual environment, and a skeletal model scaled to the injured athlete's height was used for skeletal matching. The ankle joint angle and angular velocity profiles of this acute injury were compared to the summarized findings from 19 previously reported cases in the published literature.ResultsAt foot strike, the ankle joint was 2° everted, 33° plantarflexed, and 18° internally rotated. Maximum inversion of 114° and internal rotation of 69° was achieved at 0.24 s and 0.20 s after foot strike, respectively. After the foot strike, the ankle joint moved from an initial position of plantarflexion to dorsiflexion—from 33° plantarflexion to 53° dorsiflexion (range = 86°). Maximum inversion, dorsiflexion, and internal rotation angular velocity were 1262°/s, 961°/s, and 677°/s, respectively, at 0.12 s after foot strike.ConclusionA forefoot landing posture with a plantarflexed and internally rotated ankle joint configuration could incite an acute lateral ankle sprain injury in badminton. Prevention of lateral ankle sprains in badminton should focus on the control and stability of the ankle joint angle during forefoot landings, especially when the athletes perform a combined lateral and backward step.  相似文献   

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