Validity of “Generalized” Equations for Body Composition Analysis in Women Athletes

Abstract

Equations by Jackson, Pollock, and Ward (1980) and by Durnin and Womersly (1974) for estimating body density (BD) from skinfolds (SF) purportedly overcome the criticism of “population specificity” by taking into account age and the curvilinear relationship between SFs and BD. Selected equations were validated on 79 women athletes against %fat and fat(kg) measured by underwater weighing. Equations by Sloan, Burt, and Blyth (1962), Wilmore and Behnke (1970), and Katch and McArdle (1973) were also evaluated to compare the newer equations to older ones. The mean estimate of %fat by one equation by Jackson et al. utilizing the sum of triceps, abdomen, suprailiac and thigh SF was the same as the true value (20.1%) and correlated .795 (SEE ± 3.27 total error 3.23). Regression analysis showed it to have acceptable accuracy over the range of sample values (10.3–34.0%). The Durnin-Womersly equations overestimated %fat by 3.9 to 4.4% and were not acceptable. For the older equations, the mean Sloan et al. estimate (20.8 %Fat) was not significantly different from the true value and correlated .779 (SEE ± 3.37 total error 3.47). Regression analysis showed it to overestimate fat in leaner subjects and to underestimate it in fatter ones, making it unacceptable. The Wilmore-Behnke equation overestimated %fat by 4.3%. Equations by Jackson et al., using the sum of triceps, suprailiac and thigh skinfolds, and by Katch and McArdle were shown to be acceptable if the ordinate values were adjusted (1.0994921 to 1.1074921 and 1.08347 to 1.09147 respectively) to account for the higher density of women athletes.     

Development and validation of Coaches’ Interpersonal Style Questionnaire

Purpose: The objectives were to develop and validate the Coaches’ Interpersonal Style Questionnaire. The Coaches’ Interpersonal Style Questionnaire analyzes the interpersonal style adopted by coaches when implementing their strategy of supporting or thwarting athletes’ basic psychological needs. Method: In Study 1, an exploratory factor analysis was performed with 265 Spanish male athletes, between 11- and 17-years-old, to confirm the internal structure of the questionnaire. Study 2 was conducted with 430 athletes, also between 11- and 17-years-old. Both confirmatory factor analysis and exploratory structural equation modeling were used to test a set of alternative models to find the best measurement model. Results: The hierarchical exploratory structural equation modeling model showed the best fit to the data and acceptable standardized factor loadings. Concurrent validity was revealed through correlational analysis of the basic psychological need satisfaction and frustration. Conclusion: This study provides a multi-dimensional questionnaire to assess coaches’ interpersonal style perceived by athletes.     

Analysis of the Feasibility of Dancing Course in College Girls＇ Physical Education

采用问卷调查法、文献资料法、访谈法等研究方法,对在高校女生体育课中引入舞蹈课程的可行性进行较全面的分析。结果显示：舞蹈以其独特的特性和可见的练习效果深受广大学生,尤其是女大学生的喜爱与欢迎,因此,高校针对女大学生开设舞蹈课是符合现代高校体育教学发展的需求,是很有必要的。     

The Reporting and Analysis of Research Findings for Within–Subject Designs: Methodological Issues for Meta–Analysis

Abstract

The results of studying the older athlete provide inference to the possible physiological limits found at various ages and the effect of physical activity on the aging process. As a result of the increase in development of atherosclerosis with age and the high intensity effort involved in track competition, the importance of a maximal stress test prior to entering into competition was discussed. The results presented showed 40- to 75-yr-old champion track competitors to have excellent performance, cardiopulmonary function, and body composition characteristics when compared to sedentary and moderately trained subjects of similar ages. Although maximal performance and oxygen intake decreased with age, a dramatic reduction did not occur until after age 65. Body composition measures, maximal pulmonary ventilation, resting heart rate and blood pressure, and serum lipids were similar for subjects up to age 65, but showed a significant decrement thereafter. The causes of the decrement in performance and physiological function with age could not be determined, but were thought to result from a combination of factors, e.g., aging, quantity and quality of conditioning, and number of years in continuous training.     

Was Pontarii Fighting the Origin of the Gladiator-Type Retiarius? An Analysis of the Evidence

Abstract

The origin of the retiarius has always been a mystery for experts, since there seems to be no source that gives reliable information about that question. Some experts have proposed that its origin might be found in the Siege of Tyre (332 BC), when the defenders of that city used tridents and nets to repel the attackers. Yet those same experts also warn that that episode might have more to do with the invention of pontarii fighting (a modality of fighting where the retiarius took part) than with the invention of the retiarius itself, which, according to them, would have been invented before pontarii fighting. Here, I propose the idea that an attempt to re-enact the siege of Tyre around the 30s–20s BC in order to offer a new gladiatorial entertainment might have been the origin of pontarii fighting, and of the retiarius too, since in such a re-enactment, a gladiator would have been given a trident and net to play the role of the defenders of Tyre. Thus, pontarii fighting and the retiarius would have been invented at the same time (30s–20s BC), the latter as a consequence of the former.     

Analysis of Shenzhen Canoe Athletes＇ Body Function through Action Test

运用实验法对深圳市皮划艇运动员进行身体功能动作测试,对测试结果进行分析,认为整体灵活性和稳定性较好,但部分队员肩部和髋部柔韧性较差,对柔韧性训练和纠正动作提出了建议。     

Kinetic Analysis of Second Fly of Men's Long Horse Handspring Tucked Salto with 720°

本文通过对我国部分优秀男子体操运动员跳马“前手翻团身前空翻     

Quantification of the physiological loading of one week of “pre-season” and one week of “in-season” training in professional soccer players

Abstract

The aim of this study was to quantify the physiological loads of programmed “pre-season” and “in-season” training in professional soccer players. Data for players during each period were included for analysis (pre-season, n = 12; in-season, n = 10). We monitored physiological loading of training by measuring heart rate and rating of perceived exertion (RPE). Training loads were calculated by multiplying RPE score by the duration of training sessions. Each session was sub-categorized as physical, technical/tactical, physical and technical/tactical training. Average physiological loads in pre-season (heart rate 124 ± 7 beats · min^?1; training load 4343 ± 329 Borg scale · min) were higher compared with in-season (heart rate 112 ± 7 beats · min^?1; training load 1703 ± 173 Borg scale · min) (P < 0.05) and there was a greater proportion of time spent in 80–100% maximum heart rate zones (18 ± 2 vs. 5 ± 2%; P < 0.05). Such differences appear attributable to the higher intensities in technical/tactical sessions during pre-season (pre-season: heart rate 137 ± 8 beats · min^?1; training load 321 ± 23 Borg scale · min; in-season: heart rate 114 ± 9 beats · min^?1; training load 174 ± 27 Borg scale · min; P < 0.05). These findings demonstrate that pre-season training is more intense than in-season training. Such data indicate that these adjustments in load are a direct attempt to deliver training to promote specific training adaptations.     

Herculean “Myth” Aspects of Athletics

This paper argues that recent treatments of ethics in sport have accorded too much importance to the promotion and portrayal of a sport’s excellences, and too little to the consent of participants First, I consider and reject a fundamental challenge to the idea that consent should play a central role in determining the morality of action in sport – namely, Sean McAleer’s argument to the effect that consent is incapable of rendering normally impermissible actions permissible in sport. I then offer a preliminary examination of the proper relation in the moral evaluation of action in sport between considerations of consent and ‘internalist’ considerations regarding the nature and purpose of sport. Taking as my starting point J.S. Russell’s treatment of this topic, I argue that consent is the more weighty, and in many cases the more fundamental, value and that when it conflicts with internalist considerations, it is consent that takes moral priority.     

Analysis of the Mentality of China Women＇s Volleyball Team in Previous World Series Game

通过比较分析中国女排参加的历届世界大赛,在不同的比赛阶段、面对不同的对手,所抱有的比赛心态,总结中国女排参加世界大赛的经验得失,帮助现阶段中国女排重新树立自信心,以期待能为伦敦奥运会的备战提供参考。     

“Macro-structure” of developmental participation histories and “micro-structure” of practice of German female world-class and national-class football players

The study examined the “micro-structure” of football practice and the “macro-structure” of participation history of female professional football players. Participants were 29 German 1st league (Bundesliga) players, 14 of whom played on the senior national team (Olympic Champion in 2016). A questionnaire recorded the players’ positions, proportions of physical conditioning, drill-type skill exercises and playing forms within coach-led football practice, and the volume of coach-led practice and peer-led play, in both football and other sports, from childhood to adulthood. Analyses revealed that most athletes played various attacker and defender positions during development. National team players differed from their Bundesliga peers by less physical conditioning and greater proportions of playing forms within football practice. National team players also accumulated less total football practice until age 18 years, but more peer-led football and coach-led practice in other sports compared to their Bundesliga counterparts. Based on these variables, a binary logistic regression classified 93% of the national team and Bundesliga players correctly. Conclusion: A combination of long-term coach-led football practice involving a relatively large proportion of playing forms with considerable childhood/adolescent peer-led football play and coach-led practice in other sports may have facilitated adult performance among German female world-class football players.     

Analysis of Women＇s Gymnastics Movements in the Finale of the 11th National Games

对第11届全运会女子体操平衡木决赛成套的动作内容、难度价值及动作使用频率等进行统计,研究结果表明：规则的导向作用巨大,D组以上动作是成套可记入难度的主体,技巧动作以及舞蹈动作中高难的跳步动作是中国的优势;但是成套动作类型相对单一、多样化不够,个性不突出。建议提高教练员和运动员的艺术修养,编排中突出运动员风格,力争在转体动作和动作连接上有所创新突破。     

Does size of one’s community affect likelihood of being drafted into the NHL? Analysis of 25 years of data

Abstract

The consistency of community size effects in North American contexts but not elsewhere, reinforces the notion that the effect is driven by socio-cultural factors specific to the country under examination. In order to identify and understand the various forces driving the community size effect, it is important to determine whether the effect has changed over time. Stability or instability over time would assist researchers in identifying the specific socio-cultural mechanisms driving these effects. This study compared the influence of community size on the likelihood of being drafted into the National Hockey League (NHL) among Canadian ice hockey players drafted to play in the NHL between 1985 and 2009. Although there was some variability over the timespan examined, most notably in communities with between 250,000 and 499,999 inhabitants and over 1,000,000 inhabitants, trends were generally stable over time, suggesting that the socio-cultural mechanisms may have also been relatively stable, although further work is necessary to confirm this assumption.     

Historical Analysis of Participation in 161 km Ultramarathons in North America

Participation trends in 100 m (161 km) ultramarathon running competitions in North America were examined from race results from 1977 through 2008. A total of 32, 352 finishes accounted for by 9815 unique individuals were identified. The annual number of races and number of finishes increased exponentially over the study period. This growth in number of finishes occurred through a combination of (1) an increase in participation among runners ≥40 years of age from less than 40% of the finishes prior to the mid-1980s to 65–70% of the finishes since 1996, (2) a growth (p < 0.0001) in participation among women from virtually none in the late 1970s to nearly 20% since 2004, and (3) an increase in the average annual number of races completed by each individual to 1.3. While there has been considerable growth in participation, the 161 km ultramarathon continues to attract a relatively small number of participants compared with running races of shorter distances.     

Analysis and modification of verbal coaching behaviour: The usefulness of a data‐driven intervention strategy

This study tested a computer‐aided coaching analysis instrument (CAI) as part of an intervention strategy designed to modify verbal coaching behaviour. Four coaches were observed and analysed over 12 practice sessions. Coaches A, B and C received intervention feedback through CAI data, where selected behaviours were highlighted for discussion, and videotape images were used to illustrate discussion points. Coach D was provided with videotapes of his own performance and told to formulate and implement any of his own recommendations. The CAI data are primarily quantitative, so target values were created for the different dimensions of verbal behaviour. This benefited the coaches in interpreting their effectiveness and provided a reference to evaluate the magnitude of change. Written journals and audiotape recordings were also used to promote insight into the complexity of verbal behaviour and the ‘human factors’ (e.g. relationship with players, attitude to researcher) that affect behaviour modification.

Instructional effectiveness was assessed by time‐series analysis. There was evidence from each behaviour dimension that change can occur and be maintained as a result of exposure to the CAI intervention strategy. However, this is clearly contingent upon the coach understanding what is asked of him or her, and remains focused and committed to changing these particular behaviours. The analysis of Coach D's behavioural change suggests there are limitations to the sensitivity of discretionary viewing, as only two dimensions of behaviour were identified for, and resulted in, positive change. The results of this study provide support for Locke's (1984) contention that behaviour modification can occur by using data as direct feedback, as reinforcement and as information in the form of recommendations. However, the study also illuminates several factors that can negate the modification and maintenance of verbal coaching behaviour.     

Determinants of “optimal” cadence during cycling

Abstract

Cadence is one of the only variables cyclists can adjust to manage their performance and fatigue during an event. Not surprisingly, cadence has received a great deal of attention from the scientific community in an effort to identify the cadence that optimizes power output while minimizing the fatigue that is incurred. The literature appears to present conflicting results with little consensus as regards the optimal pedalling cadence. This is in large part due to the inconsistent definition of the term “optimal” cadence, which has been used to describe energetic cost, muscular stress, and perception of effort. The issue is further confounded by the workload-dependent nature of the “optimal” cadence – that is, at higher power outputs, the optimized cadence is different from that at lower power outputs. Although the optimal cadence is different for energetic, muscular, and perceptual definitions, the curves that describe the effect of changes in cadence on these variables consistently exhibit a J-shaped response. This suggests that there is an underlying principle that is common to each of the definitions. Indeed, it would appear that the response of both the cardio-respiratory system (energetic cost) and the muscular system (muscular stress) is determined by the types of muscle motor units that are recruited during the exercise. Furthermore, although part of the response may be due to the inherent differences in the characteristics between the different motor units, the absolute contraction velocity relative to fibre type optimum may be of greater significance. Even when the power output is increased, the shape of the response curves to changes in cadence remains constant, although the nadir of the curve does shift to the right for increasing power outputs. We propose that the point at which the energetic vs. power and the muscular stress vs. power curves intercept is defined by the cadence at which the perceived effort is minimized (i.e. the preferred cadence). However, cadence fluctuations occur under field conditions that are unrelated to physiological factors and, therefore, the ability to identify an “optimal” cadence is limited to the laboratory environment and specific field conditions.     

An Analysis of Conceptual Metaphors in Jack Ma’s English Public Speech

马云是中国一名成功的企业家。他被世界经济论坛评选为“年轻的全球领袖”,被中央电视台评选为“年度十大商业领袖”。马云在国内外做过多场成功而富有影响的演讲。本文将从概念隐喻的角度对马云在国外的三篇英文演讲进行分析。     

On the Effect of Concept of Physical Education on Modern College Students＇ Life Style——with the Field Survival Training as an Example

通过文献资料阐述了现代生活方式的概念及其涵义,分析了现代社会由于经济的全球化,文化的多元化,使现代大学生的生活方式发生了一些嬗变,严重影响了他们的健康成长;并以野外生存生活训练为例剖析了其中所蕴含的体育理念,论证了在大学校园里这些体育理念的渗透能科学地引领大学生的生活方式,使其成为未来社会的一个正常的、快乐的、智力的、有实力的人。     

Specificity of Individual Differences of Relationship between Forearm “Strengths” and Speed of Forearm Flexion

Abstract

Forearm flexion strength of 65 college men was measured at two distances from the elbow at each of three angles of the forearm. The speed of forearm flexion movement was measured through an arc of 85°. Ebel intraclass reliabilities for strength and speed were high, i.e., .95 to .99. The extremely low correlations between limb strength and speed of movement, which ranged from —.06 to .14, are in agreement with the majority of the low correlations reported in earlier studies. The findings of this study support the theory of specificity in that individual differences in the speed of a limb involving a single joint are predominantly independent of strength measures associated with that limb and joint.