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1.
Environmental and genetic factors influence muscle function, resulting in large variations in phenotype between individuals. Multiple genetic variants (polygenic in nature) are thought to influence exercise-related phenotypes, yet how the relevant polymorphisms combine to influence muscular strength in individuals and populations is unclear. In this analysis, 22 genetic polymorphisms were identified in the literature that have been associated with muscular strength and power phenotypes. Using typical genotype frequencies, the probability of any given individual possessing an "optimal" polygenic profile was calculated as 0.0003% for the world population. Future identification of additional polymorphisms associated with muscular strength phenotypes would most likely reduce that probability even further. To examine the genetic potential for muscular strength within a human population, a "total genotype score" was generated for each individual within a hypothetical population of one million. The population expressed high similarity in polygenic profile with no individual differing by more than seven genotypes from a typical profile. Therefore, skeletal muscle strength potential within humans appears to be limited by polygenic profile similarity. Future research should aim to replicate more genotype-phenotype associations for muscular strength, because only five common genetic polymorphisms identified to date have positive replicated findings.  相似文献   

2.
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   

3.
Abstract

High-level physical performance in rhythmic gymnastics is influenced by numerous skills and anthropometric factors. In order to understand if genetic predisposition could play a role to define the elite rhythmic gymnast phenotype, we analysed the frequency of common polymorphisms linked to genes correlated with body mass (ADRB2 and FTO), explosive strength (ACTN3 and ACE), and joint mobility (COL5A1), in 42 gymnasts involved in National and International events, and in 42 control girls. Our results demonstrated that high-level rhythmic gymnasts constituted a genetically selected population showing higher frequency of: (a) ADRB2 and FTO alleles linked to low body mass index and low fat mass; (b) COL5A1 CT genotype linked to high joint mobility and to the occurrence of genu recurvatum, but also to a higher incidence of injuries. ACTN3 and ACE polymorphisms did not appear to be connected with the phenotype of high-level rhythmic gymnast. Based on these data, it can be assumed that these polymorphisms could positively affect the phenotype and performance of gymnasts.  相似文献   

4.
Muscle weakness is considered a risk factor for ankle injury. Balance training and barefoot running have been used in an attempt to strengthen the muscles crossing the ankle. It is expected that training tasks that successfully strengthen the ankle would elicit increased muscular activity. However, it is unknown how an individual's ankle strength will influence the muscle activity used during a given task. Twenty-six participants performed dynamic (shod, barefoot running) and static tasks (squat on ground, squat on ®Bosu Ball) believed to strengthen the muscles surrounding the ankle. Electromyographic signals of the tibialis anterior, peroneus longus, gastrocnemius lateralis (GL) and gastrocnemius medialis (GM) were recorded and analysed using a non-linearly scaled wavelet analysis. Participants were divided into a strong group and a weak group according to their isometric plantar-flexion torque. The weak group required more relative GL and GM muscle activity during each training task compared to the strong group. No difference was observed between shod and barefoot running. There was a significant effect of training task on muscle activation level for the weak group. Differences in ankle strength had a significant impact on muscle activation.  相似文献   

5.
目的:回顾目前在理解运动员能力遗传决定论方面的进展,并描述一些新的、重要的、可能成为精英运动员的差异标记的基础的DNA多态性。方法:通过文献综述和归纳分析法对过去几十年运动基因组学的研究进展作了简单的回顾。结果:运用全基因组关联研究(GWAS),在过去几年确定了41种标志物,这表明GWASs是一种有前景、富有成效的研究运动相关表型的方法。结论:未来的研究,包括多中心GWAS和大群运动员的全基因组测序的验证和复制研究,将有助于发现大量能部分解释运动能力和相关表型的遗传力的遗传变异(突变和DNA多态性)。  相似文献   

6.
The purposes of this study were to analyse (a) if “angle-specific” (AS) flexor and extensor torques were different between ACL-reconstructed and uninvolved limbs, (b) the difference in peak torque occurrence angles for concentric and eccentric knee flexor and extensor torques between involved and uninvolved limbs and (c) if AS concentric and eccentric knee flexor and extensor torques are determinants of performance in the “single-leg hop test” (SLHT) and “vertical jump and reach test” (VJRT) in ACL-reconstructed legs. Twenty-seven male ACL-reconstructed volunteers were included in the study. Isokinetic knee muscle strength, SLHT and VJRT were performed 6 months after ACL reconstruction. No difference was found in extremity and knee joint angle interaction for concentric and eccentric flexor and extensor torques (p > 0.05). Peak torque occurrence angles were not different between involved and uninvolved limbs (p > 0.05). In involved extremities, concentric knee extensor strength at 90° was a determinant of SLHT performance (R2 = 0.403, p < 0.05), and concentric knee extensor strength at 60° was a determinant of VJRT (R2 = 0.224, p < 0.05). Assessment of AS concentric knee extensor strength at 60° and 90° might be important, because these were determinants of functional test performance.  相似文献   

7.
Shoulders of elite field hockey players are loaded continuously during play. However, shoulder girdle muscle performance in this population has never been examined yet. This study aimed to compare isokinetic shoulder girdle performance in elite male field hockey players to matched controls, with respect to strength, endurance and muscle balance. The complete male national field hockey team of Belgium (n = 25) was included and matched to a gender- and age-matched control group of healthy participants (n = 25). A Biodex system-4 dynamometer was used to measure glenohumeral and scapular muscle strength at 2 velocities in a concentric/concentric mode. With the main outcome measures being isokinetic strength values, peak force (protraction-retraction), peak torque (rotations), fatigue index and agonist/antagonist ratio’s. Measurement results showed that elite male field hockey players were stronger than their matched controls, for both the rotational and the protraction-retraction movement. Concerning rotational strength, symmetrical findings were established, contrary to scapular strength, where side differences were noted. At low velocity, retraction peak force was higher on the dominant side. Protraction peak force was higher on the non-dominant side when measured at high velocity. In conclusion, elite field hockey players have a symmetrical rotational strength profile, in contrast to their scapular strength profile.  相似文献   

8.
Abstract

Masculinity and femininity ratings were studied in relation to motor performance scores of college women. Arm strength, muscular explosive power, pure speed, and the Humiston Test of motor ability showed a significant positive relationship to andric ratings and a significant negative relationship to gynic ratings. Subjects were classified as being “above”, “at”, or “below” the established mean of the andric and gynic factors. Comparison of mean scores revealed those above the andric mean to be superior on tests of speed, arm strength, and motor ability. Those below the mean of the gynic factor were found to be superior on these same tests and on explosive power. The extent to which the physical expression of masculinity exceeded that of femininity was more highly related to performance scores than were either masculinity or femininity ratings alone.  相似文献   

9.
The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad x s(-1) (3.14 rad x s(-1)) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P < 0.05-0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r < 0.26, N.S.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r = 0.38-0.64, P < 0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength-CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.  相似文献   

10.
Abstract

The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad·s?1 (3.14 rad·s?1) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P<0.05–0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r<0.26, n.s.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r=0.38–0.64, P<0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength—CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.  相似文献   

11.
The aim of the study was to assess the relationship between performance-based and laboratory tests for muscular strength and power assessment in older women. Thirty-two women aged 68.8 +/- 2.8 years were recruited. All participants were asessed for: (a) two performance-based tests--the box-stepping test (mean 296 +/- 51 J) and two-revolution maximum test (mean 7.1 +/- 2 kg) performed while pedalling on a cycle ergometer; and (b) muscular function tests--maximal instantaneous peak power jumping on a force platform (mean 1528 +/- 279 W); maximal voluntary contraction (MVC) during knee extension (mean 601 +/- 571 N) and leg press (mean 626 +/- 126 N), and leg press power (mean 483 +/- 98 W) on a dynamometer. Using univariate analysis, performance-based tests were compared with laboratory muscle strength and power measurements. Muscle power correlated most strongly with the performance-based tests for both jumping and leg press power (r-values between 0.67 and 0.75; P < 0.01). The correlation with muscle strength measures ranged between 0.48 and 0.61 (P < 0.01). The proposed tests may have particular relevance in geriatric and rehabilitation environments as they represent an easy, practical, and inexpensive alternative for the assessment of muscular strength and power.  相似文献   

12.
The purpose of this study was to examine the psychosocial correlates of cardiorespiratory fitness (VO2peak) and muscle strength in overweight and obese sedentary post-menopausal women. The study population consisted of 137 non-diabetic, sedentary overweight and obese post-menopausal women (mean age 57.7 years, s = 4.8; body mass index 32.4 kg.m(-2), s = 4.6). At baseline we measured: (1) body composition using dual-energy X-ray absorptiometry; (2) visceral fat using computed tomography; (3) insulin sensitivity using the hyperinsulinaemic-euglycaemic clamp; (4) cardiorespiratory fitness; (5) muscle strength using the leg press exercise; and (6) psychosocial profile (quality of life, perceived stress, self-esteem, body-esteem, and perceived risk for developing chronic diseases) using validated questionnaires. Both VO2peak and muscle strength were significantly correlated with quality of life (r = 0.29, P < 0.01 and r = 0.30, P < 0.01, respectively), and quality of life subscales for: physical functioning (r = 0.28, P < 0.01 and r = 0.22, P < 0.05, respectively), pain (r = 0.18, P < 0.05 and r = 0.23, P < 0.05, respectively), role functioning (r = 0.20, P < 0.05 and r = 0.24, P < 0.05, respectively), and perceived risks (r = -0.24, P < 0.01 and r = -0.30, P < 0.01, respectively). In addition, VO2peak was significantly associated with positive health perceptions, greater body esteem, and less time watching television/video. Stepwise regression analysis showed that quality of life for health perceptions and for role functioning were independent predictors of VO2peak and muscle strength, respectively. In conclusion, higher VO2peak and muscle strength are associated with a favourable psychosocial profile, and the psychosocial correlates of VO2peak were different from those of muscle strength. Furthermore, psychosocial factors could be predictors of VO2peak and muscle strength in our cohort of overweight and obese sedentary post-menopausal women.  相似文献   

13.
Abstract

Introduction: Previous studies have attempted to link the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene with the variability in muscle strength responses to resistance training (RT); however, the literature is inconclusive. The purpose of the present study was to investigate the association between the ACE I/D genotype and muscle strength response to a RT program in young men.

Methods: 124 men (22±2.6 years; 174.8±6.5cm; 71.5±13.8 kg) without resistance training experience were tested before and after 11 weeks of five whole-body RT exercises (bench press, seated row, knee extension, knee flexion and sit ups). The bench press 1RM test was used to assess upper-body muscle strength and the isokinetic knee extensor peak torque (PT) was used as a measure of lower-body strength.

Results: At baseline, there were no differences among ACE genotype for 1RM load (54±11.7 kg for II, 58.5±8.9 kg for ID and 52.3±12.2 kg for DD) or knee extensor peak torque (PT) (220.1±36.8 N·m for II, 209.4 ±44.4 N·m for ID and 199.7±32.4 N·m for DD). Moreover, ACE genotype was not associated with lower-body (7.1±10.5%, 15.7±10.4% and 14.1±22.7% for II, ID and DD, respectively) or upper-body strength gains (16.2±8.9%, 14.5±11.3% and 21.9±17.1% for II, ID and DD, respectively) in response to RT.

Conclusion: The ACE I/D genotype was not associated with the muscle strength responses to RT.  相似文献   

14.
The purpose of this study was to compare the content and quantity of competitive and organizational stressors in elite athletes. Ten international performers were interviewed about sources of stress. Content analysis of the data involved categorizing the demands associated primarily and directly with competitive performance (#CS = 21) under the post hoc dimension “performance issues”, and the demands associated primarily and directly with the sport organization (#OS = 72) under one of the following four post hoc dimensions: “environmental issues”, “personal issues”, “leadership issues” and “team issues”. Frequency analysis revealed that the participants mentioned the competitive stressors (Σ = 95) less than the organizational stressors (Σ = 215). Further analysis within these categories showed that the mean number of participants citing individual competitive stressors (M = 4.52) was greater than the mean number of participants citing individual organizational stressors (M = 2.99). The findings indicate that elite athletes experience and recall more demands associated primarily and directly with the sport organization than with competitive performance. Furthermore, this population appears more likely to mention similar competitive stressors but varied organizational stressors, probably because the former are inherent and endemic to elite sport, whereas the latter are essentially extraneous and widely distributed.  相似文献   

15.
BackgroundThe majority of injuries reported in female basketball players are ankle sprains and mechanisms leading to injury have been debated. Investigations into muscular imbalances in barefoot versus shod conditions and their relationship with injury severity have not been performed. The purpose of this study was to investigate the effects of wearing athletic shoes on muscular strength and its relationship to lower extremity injuries, specifically female basketball players due to the high incidence of ankle injuries in this population.MethodsDuring pre-season, 11 female collegiate basketball players underwent inversion and eversion muscle strength testing using an isokinetic dynamometer in both a barefoot and shod conditions. The difference between conditions was calculated for inversion and eversion peak torque, time to peak torque as well as eversion-to-inversion peak torque percent strength ratio for both conditions. Lower extremity injuries were documented and ranked in severity. The ranked difference between barefoot and shod conditions for peak torque and time to peak torque as well as percent strength ratio was correlated with injury ranking using a Spearman rho correlation (ρ) with an α level of 0.05.ResultsThe ranked differences in barefoot and shod for peak eversion and inversion torque at 120°/s were correlated with their injury ranking. Ranking of the athletes based on the severity of injuries that were sustained during the season was found to have a strong, positive relationship with the difference in peak eversion torque between barefoot and shod (ρ = 0.78; p = 0.02).ConclusionIt is possible that a large discrepancy between strength in barefoot and shod conditions can predispose an athlete to injury. Narrowing the difference in peak eversion torque between barefoot and shod could decrease propensity to injury. Future work should investigate the effect of restoration of muscular strength during barefoot and shod exercise on injury rates.  相似文献   

16.
The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.  相似文献   

17.
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   

18.
目的:通过胰岛素样生长因子结合蛋白3(IGFBP3)基因多态性与低氧训练-高住高练低训(HiHiLo)后左心室功能训练效果的关联性分析,为预测低氧训练效果,制定个性化低氧训练方案提供分子标记.方法:68名男子大学生运动员接受为期4周HiHiLo训练,使用Doppler超声心动仪测试其训练前、后安静状态和递增负荷运动下的心功能指标.采用PCR-RFLP方法解析受试者IGFBP3基因A-202C、Pro158His位点的多态性,并与训练前、后心功能指标进行关联分析.结果:A-202C位点多态性与50 W/SV和CO、100 W/SV和CO初始值关联,均为AA基因型高于AC基因型;与150 W/HR、CI的训练效果关联,表现为AA基因型变化显著;Pro158His位点多态性与50W/EF、CO和CI,100W/CO初始值关联,均为AA基因型高于AC基因型,与安静状态/HR、50W/SI、100W/SI的训练效果关联,表现为AC基因型变化显著.结论:IGFBP3基因A-202C位点从基因型和Pro158His位点AC基因型对于4周HiHiLo训练在左心室功能方面表现出较好的敏感性,可作为预测低氧训练效果的分子标记.  相似文献   

19.
Abstract

The aim of the study was to assess the relationship between performance-based and laboratory tests for muscular strength and power assessment in older women. Thirty-two women aged 68.8 ± 2.8 years were recruited. All participants were asessed for: (a) two performance-based tests – the box-stepping test (mean 296 ± 51 J) and two-revolution maximum test (mean 7.1 ± 2 kg) performed while pedalling on a cycle ergometer; and (b) muscular function tests – maximal instantaneous peak power jumping on a force platform (mean 1528 ± 279 W); maximal voluntary contraction (MVC) during knee extension (mean 601 ± 571 N) and leg press (mean 626 ± 126 N), and leg press power (mean 483 ± 98 W) on a dynamometer. Using univariate analysis, performance-based tests were compared with laboratory muscle strength and power measurements. Muscle power correlated most strongly with the performance-based tests for both jumping and leg press power (r-values between 0.67 and 0.75; P < 0.01). The correlation with muscle strength measures ranged between 0.48 and 0.61 (P < 0.01). The proposed tests may have particular relevance in geriatric and rehabilitation environments as they represent an easy, practical, and inexpensive alternative for the assessment of muscular strength and power.  相似文献   

20.
Football is central to the lives of countless individuals around the globe. While most of the attention of those passionate about the sport is focused on the players, football referees are often just as important in shaping the outcome of the games. Therefore, research is increasingly examining the role of referees. Even so, our understanding of the factors that create an excellent football referee is still scarce.

Based on our analysis of the opinions of 24 football experts, we demonstrate the multidimensionality of excellence in the performance of football referees. From a Categorical Principal Components Analysis (CatPCA), we were able to pinpoint that football referee excellence is shaped by three distinct dimensions: individual preparation, game preparation and game management. Additionally, we were able to see if these perceptions were different from individuals “within” the game versus those “outside” the game. Namely, we used CatPCA to graphically display the main correlations between the latent dimensions of football refereeing performance and the “inside” and “outside” perspective of the game. The findings of our work contribute towards the knowledge of the factors that shape football referee excellence, while also highlighting areas in need of additional research attention.  相似文献   


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