首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The purpose of this study was to compare changes in aerobic condition, strength, and muscular endurance following 8 weeks of endurance rowing alone or in combination with weight-training. Twenty-two elite rowers were assigned to (1) rowing (n = 10, 250-270 km · week?1) or (2) rowing (n = 12, 190-210 km · week?1) plus four weight-training sessions each week. Pre and post mean and standardized effect-size (ES) differences in aerobic condition (watts at 4 mmol · L?1) and strength (isometric pull, N), prone bench-pull (6-repetition maximum, 6-RM), 5- and 30-repetition leg-press and 60-repetition seated-arm-pull (J, performed on a dynamometer) normalized by body mass and log-transformed were analysed, after adjusting for gender. The standardized differences between groups were trivial for aerobic condition (ES [±90% CI] = 0.15; ±0.28, P = 0.37) and prone bench-pull (ES = 0.27; ±0.33, P = 0.18), although a moderate positive benefit in favour of rowing only was observed for the seated-arm-pull (ES = 0.42; ±0.4, P = 0.08). Only the weight-training group improved isometric pull (12.4 ± 8.9%, P < 0.01), 5-repetition (4.0 ± 5.7%, P < 0.01) and 30-repetition (2.4 ± 5.4%, P < 0.01) leg-press. In conclusion, while gains in aerobic condition and upper-body strength were comparable to extensive endurance rowing, weight-training led to moderately greater lower-body muscular-endurance and strength gains.  相似文献   

2.
Abstract

The aims of this study were to examine training characteristics, body composition, muscular strength, and endurance in sport climbers, and to demonstrate the relationship among these components by means of structural equation modelling. Altogether, 205 sport climbers (136 males, 69 females), with a performance RP (red point) of grade 4 to 11 on the Union Internationale des Association d'Alpinisme (UIAA) scale, took part in the study. The proposed structural model, with latent variable hand–arm strength and endurance (developed from reference values for simple tests), indicated by three manifest variables (grip strength, bent-arm hang, and finger hang) and three exogenous variables (body fat, volume of climbing, and climbing experience), explained 97% of the variance in climbing performance. The relationship between body fat and climbing experience/volume with climbing performance was not direct, but was better explained using the mediator hand–arm strength and endurance. We conclude that these simple tests, together with percent body fat, volume of climbing, and climbing experience, can satisfactorily predict climbing performance.  相似文献   

3.
The hypothesis that endurance training impairs sprinting ability was examined. Eight male subjects undertook a 30‐s sprint test on a cycle ergometer before and after 6 weeks of cycling training for endurance. Maximum oxygen uptake (VO2 max) and submaximum endurance were determined to evaluate the influence of the training regimen on endurance performance. Endurance was defined as the time to exhaustion at a relative exercise intensity of 85% VO2 max. Maximum oxygen uptake was increased by 18% post‐training (3.29 ± 0.291 min–1 versus 3.89±0.491 min–1; P <0.01), but endurance at the same absolute work rate as pre‐training was increased by more than 200% (32.2 ±11.4 min versus 97.8 + 27.3 min; P <0.01). These improvements were accompanied by changes in the cardiovascular and metabolic responses to standard, submaximum exercise. Despite the improvements in endurance, neither performance during the cycle sprint test nor the increase in blood lactate concentration during the sprint was influenced by endurance training. For short‐term cycling training, these findings reinforce the concept of training specificity whilst demonstrating that decrements in sprint performance are not a necessary consequence of improved endurance.  相似文献   

4.
Abstract

Six games players (GP) and six endurance‐trained runners (ET) completed a standardized multiple sprint test on a non‐motorized treadmill consisting often 6‐s all‐out sprints with 30‐s recovery periods. Running speed, power output and oxygen uptake were determined during the test and blood samples were taken for the determination of blood lactate and pH. Games players tended to produce a higher peak power output (GP vs ET: 839 ± 114 vs 777 ± 89 W, N.S.) and higher peak speed (GP vs ET: 7.03 ± 0.3 vs 6.71 ± 0.3 m s‐1, N.S.), but had a greater decrement in mean power output than endurance‐trained runners (GP vs ET: 29.3 ± 8.1% vs 14.2 ± 11.1%, P < 0.05). Blood lactate after the test was higher for the games players (GP vs ET: 15.2 ± 1.9 vs 12.4 ± 1.7 mM, P < 0.05), but the decrease in pH was similar for both groups (GP vs ET: 0.31 ± 0.08 vs 0.28 ± 0.08, N.S.). Strong correlations were found between peak blood lactate and peak speed (r = 0.90, P < 0.01) and between peak blood lactate and peak power fatigue (r = 0.92, P<0.01). The average increase in oxygen uptake above pre‐exercise levels during the sprint test was greater for endurance‐trained athletes than for the games players (ET vs GP: 35.0 ± 2.2 vs 29.6 ± 3.0 ml kg‐1 min‐1 , P < 0.05), corresponding to an average oxygen uptake per sprint (6‐s sprint and 24 s of subsequent recovery) of 67.5 ± 2.9% and 63.0 ± 4.5% VO 2 max respectively (N.S.). A modest relationship existed between the average increase in oxygen uptake above pre‐exercise values during the sprint test and mean speed fatigue (r = ‐0.68, P < 0.05). Thus, the greater decrement in performance for the games players may be related to higher glycolytic rates as reflected by higher lactate concentrations and to their lower oxygen uptake during the course of the 10 sprints.  相似文献   

5.
We have previously shown that single‐leg training results in improved endurance for exercise with the untrained leg (UTL) as well as for exercise with the trained leg (TL). The purpose of this study was to see whether the improved endurance of the untrained leg could be explained on the basis of changes in muscle metabolism. Exercise time to exhaustion at 80% of maximum oxygen uptake (VO2 max) was determined for each leg separately, pre‐ and post‐training. Muscle metabolite concentrations were measured pre‐ and post‐training in biopsy samples obtained immediately before this endurance test and at the pre‐training point of exhaustion (END1). After six weeks of single‐leg training endurance time was increased for both the UTL and the TL (UTL 34.0+16.4 min vs 97.9±26.3 min, P<0.01; TL 28.3 + 10.1 min vs 169.0 + 32.6 min, P < 0.01). No changes in muscle metabolite concentrations were found in resting muscle. Training increased muscle ATP (P <0.05) and glycogen (P <0.01) concentrations and decreased muscle lactate concentration (P<0.05) in the TL at END1. No significant changes in muscle metabolite concentrations were found for the UTL. The improved endurance of the contralateral limb after single‐leg training could not be explained on the basis of changes in muscle metabolism.  相似文献   

6.
The purpose of this study was to test the hypothesis that increased availability of blood‐borne glucose would improve endurance after carbohydrate loading. A single‐leg exercise model was employed, taking advantage of the fact that supercompensation of muscle glycogen occurs only in a previously exercised limb. Endurance time to exhaustion at 70% of maximal oxygen uptake (VO2max) was determined for 11 males and three females who were then allocated to a control group or a high‐carbohydrate (CHO) group. For 3 days following Test 1 the control group maintained a prescribed normal diet whilst the CHO group increased the proportion of energy derived from carbohydrate (62.1 ± 4.3% cf. 43.9 ± 2.0%, P < 0.01). The endurance test was then repeated using the leg that was inactive during Test 1. Endurance time was increased on Test 2 (123.7 ± 43.2 min cf. 98.5 ± 21.9 min, P <0.05 one‐tailed test) for the CHO group but not for the control group (101.8 ± 21.7 min cf. 107.5 ± 9.1 min, NS). There was no indication of enhanced carbohydrate metabolism during Test 2 for the CHO group but mean heart rate was lower during Test 2 than during Test 1 (145 ± 14 beat min ‐1 cf. 152 ± 12 beat min ‐1, P<0.05). These results suggest that the prior consumption of a high‐carbohydrate diet improves endurance during high‐intensity cycling with a limb with normal muscle glycogen concentration.  相似文献   

7.
Abstract

There are no studies available that portray insulin sensitivity and β-cell function in ageing sprint-trained athletes. We compared male young and master sprint-trained athletes to endurance-trained and untrained individuals. We hypothesised that ageing sprint-trained athletes would preserve insulin sensitivity and β-cell function at a level similar to that of endurance-trained peers and better than in untrained individuals. We showed the associations between age and parameters derived from the updated Homeostasis Model Assessment (HOMA2 model) in 52 sprint-trained track and field athletes (aged 20?90 years), 85 endurance runners (20?80 years) and 55 untrained individuals (20?70 years). Fasting glucose, fasting insulin, insulin sensitivity and β-cell function were not associated with age in sprint-trained athletes. These variables remained relatively stable across a wide range of age and comparable to those observed in endurance-trained athletes. In contrast, the untrained group showed considerable age-related increase in fasting insulin and β-cell activity and a strong decrease in insulin sensitivity compared to both athletic groups. HOMA2 parameters were significantly related to maximal oxygen in the combined group of participants. In summary, chronic training based on a “sprint model” of physical activity, that contains mixed exercise, seems to be effective in maintaining normal insulin sensitivity with ageing.  相似文献   

8.
  相似文献   

9.
Abstract

We examined the reliability and validity of the assistant referee intermittent endurance test (ARIET), a modified Yo-Yo IE2 test including shuttles of sideways running. The ARIET was carried out on 198 Italian (Serie A-B, Lega-Pro and National Level) and 47 Danish elite soccer assistant referees. Reproducibility was tested for 41 assistant referees on four occasions each separated by one week. The ARIET intraclass correlation coefficients and typical error of measurement ranged from 0.96 to 0.99 and 3.1 to 5.7%, respectively. ARIET performance for Serie A and B was 23 and 25% greater than in Lega-Pro (P < 0.001). The lowest cut-off value derived from receiving operator characteristic discriminating Serie A-B from Lega-Pro was 1300 m. The ARIET performance was significantly correlated with [Vdot]O2max (r = 0.78, P < 0.001), %HRmax after 4 min of ARIET (r = ? 0.81, P < 0.001) and Yo-Yo IR1 performance (r = 0.95, P < 0.001), but not sprint performance (r = ?0.15; P = 0.58). The results showed that ARIET is a reproducible and valid test that is able to discriminate between assistant referees of different competitive levels. The lack of correlation with sprinting ability and close correlations with aerobic power, intermittent shuttle running and sub-maximal ARIET heart rate loading provide evidence that ARIET is arelevant test for assessment of intermittent endurance capacity of soccer assistant referees.  相似文献   

10.
The aim of this study was to examine the effects of ingesting a carbohydrate‐electrolyte solution on endurance capacity during a prolonged intermittent, high‐intensity shuttle running test (PIHSRT). Nine trained male games players performed two exercise trials, 7 days apart. On each occasion, they completed 75 min exercise, comprising of five 15‐min periods of intermittent running, consisting of sprinting, interspersed with periods of jogging and walking (Part A), followed by intermittent running to fatigue (Part B). The subjects were randomly allocated either a 6.9% carbohydrate‐electrolyte solution (CHO) or a non‐carbohydrate placebo (CON) immediately prior to exercise (5 ml kg‐1 body mass) and every 15 min thereafter (2 ml kg‐1 body mass). Venous blood samples were obtained at rest, during and after each PIHSRT for the determination of glucose, lactate, plasma free fatty acid, glycerol, ammonia, and serum insulin and electrolyte concentrations. During Part B, the subjects were able to continue running longer when fed CHO (CHO = 8.9 ± 1.5 min vs CON = 6.7 ± 1.0 min; P < 0.05) (mean ± s.e.m.). These results show that drinking a carbohydrate‐electrolyte solution improves endurance running capacity during prolonged intermittent exercise.  相似文献   

11.
This study aimed to determine whether kinematic data during countermovement jump (CMJ) might explain post-activation potentiation (PAP) phenomenon after an exhausting running test. Thirty-three trained endurance runners performed the Léger Test; an incremental test which consists of continuous running between two lines 20 m apart. CMJ performance was determined before (pre-test) and immediately after the protocol (post-test). Sagittal plane, video of CMJs was recorded and kinematic data were obtained throughout 2-Dimensional analysis. In addition to the duration of eccentric and concentric phases of CMJ, hip, knee and ankle angles were measured at four key points during CMJ: the lowest position of the squat, take-off, landing, and at the lowest position after landing. Additionally, heart rate was monitored, and rate of perceived exertion was recorded at post-test. Analysis of variance revealed a significant improvement in CMJ (p = 0.002) at post-test. Cluster analysis grouped according to whether PAP was experienced (responders group: RG, n = 25) or not (non-responders group: NRG, n = 8) relative to CMJ change from rest to post-test. RG significantly improved (p < 0.001) the performance in CMJ, whereas NRG remained unchanged. Kinematic data did not show significant differences between RG and NRG. Thus, the data suggest that jumping kinematic does not provide the necessary information to explain PAP phenomenon after intensive running exercises in endurance athletes.  相似文献   

12.
  相似文献   

13.
Sprint and distance running have experienced remarkable performance improvements over the past century. Attempts to forecast running performances share an almost similarly long history but have relied so far on relatively short data series. Here, we compile a comprehensive set of season-best performances for eight Olympically contested running events. With this data set, we conduct (1) an exponential time series analysis and (2) a power-law experience curve analysis to quantify the rate of past performance improvements and to forecast future performances until the year 2100. We find that the sprint and distance running performances of women and men improve exponentially with time and converge at yearly rates of 4% ± 3% and 2% ± 2%, respectively, towards their asymptotic limits. Running performances can also be modelled with the experience curve approach, yielding learning rates of 3% ± 1% and 6% ± 2% for the women's and men's events, respectively. Long-term trends suggest that: (1) women will continue to run 10–20% slower than men, (2) 9.50 s over 100 m dash may only be broken at the end of this century and (3) several middle- and long-distance records may be broken within the next two to three decades. The prospects of witnessing a sub-2 hour marathon before 2100 remain inconclusive. Our results should be interpreted cautiously as forecasting human behaviour is intrinsically uncertain. The future season-best sprint and distance running performances will continue to scatter around the trends identified here and may yield unexpected improvements of standing world records.  相似文献   

14.
  相似文献   

15.
Drawing from recent debates about Muslim immigrants’ lack of integration into European societies, the current article advances a main argument regarding the nexus between soccer and Muslim immigrants’ integration within their host European societies by reviewing dominant theoretical models and focusing on elite European male Muslim soccer players. Considering the growing recent debate about the role of Muslim immigrants in their European societies, soccer has the potential to assist European countries to increase Muslims’ integration level. Elite Muslim soccer players are among the most influential immigrants in European societies. Muslim soccer players could contribute to increase understanding and community unity between different social groups within European societies as many of them prove that identity hyphenation and combining ethnicity and European nationality is possible for Muslim immigrants. Soccer could give more confidence to the generation of young Muslims about being accepted by European majorities.  相似文献   

16.
Abstract

This paper examines varieties of naiveté manifested in the world of sport. In particular, I examine epistemological, ethical, and metaphysical naiveté. My contention is that virtually from cradle to grave forms of naiveté toward sport are present. We are tempted and all too often succumb to the temptation to accept appearances. But the initial appearances of sport often disappoint, and the underlying reality that confronts us is sometimes a hard reality. Faced with disappointment and exposed illusions, one’s next step may be to adopt a hermeneutics of suspicion towards sport. There is no going back to the earlier naive stance. But is this the final word on the matter? Once one has adopted a critical perspective towards sport, is it possible to join the hermeneutics of suspicion to what Wendy Doniger refers to as a “hermeneutics of retrieval”? That is, after the first naiveté toward sport is exposed as inadequate, is it possible to arrive at what the philosopher Paul Ricoeur calls a “second naiveté” that allows one to appreciate, in a renewed and legitimate way, a phenomenon such as sport, subsequent to the loss of layers of innocence? In this paper I examine whether, in the case of sport, this can be done with integrity.  相似文献   

17.

Though agencies, such as the Canadian Centre for Ethics in Sport and the Australian Sports Drug Agency, argue that much effort is being directed toward educating athletes about the virtues of fair play, the risks of drug use, and the ethics of cheating, the primary focus of government led initiatives is catching cheaters through testing. As a result, a decade following the inaugural Canadian Inquiry random drug testing is an accepted part of the culture of elite sport and is recognised as the most powerful deterrent for prospective abusers. As public confidence rests implicitly upon testing as the best and only direct means to establish a fair level of competition, it is perhaps not surprising that little attention is given to the ethical implications of testing as an invasion of privacy. The purpose of this paper is to investigate the ethical implications of testing athletes for the use of banned substances and determine if the current course of action is a morally justified suspension of privacy.  相似文献   

18.
Elite track and field athletes with greater and lesser multi-year performance improvement were compared regarding their developmental sport-specific and non-specific, organised (coach-led) and non-organised (peer-led) sporting activities. Athlete pairs were matched on gender, discipline and baseline performance in competitions (at 13/19 years). Their unequal subsequent performance development during junior (13–17 years; n = 138) and senior (19–23+ years; n = 80) age ranges defined “strong responders” and “weak responders”. Analyses revealed that junior-age strong responders accumulated more organised practice in athletics than weak responders, while the amounts of all other types of activities were indifferent. Senior-age strong responders did not accumulate a greater total sum of all kinds of sport activities or greater amounts of organised practice in athletics or non-organised involvement in athletics or other sports than weak responders. But they engaged in more organised practice and competitions in other sports over more years (9 vs. 2 years) and specialised in athletics at a later age than weak responders (16 vs. 11 years). The results were also robust among senior international medallists vs. national medallists. The findings are reflected relative to the hypotheses of “multiple sampling and functional matching”, “learning transfer as preparation for future learning” and “authenticity of variable learning experiences”.  相似文献   

19.
Current problems of health - related fitness promotion in children and adolescents- economic, social, cultural and other environmental factors. A relationship between the environment and the child, beginning dining the gestation period that influences both positive and negative, health outcomes later in life.[第一段]  相似文献   

20.
Background: The universal sport discourses of meritocracy and equality are so engrained that few challenge them. The most cursory interest in sport, Physical Education (PE), and society will reveal that the lived reality is quite different. Racial disparities in the leadership and administration of sport are commonplace worldwide; yet, from research into ‘race’ in sport and PE, awareness of these issues is widespread, where many know that racism takes place it is generally claimed to be somewhere else or someone else. For many, this racism is part of the game and something to manipulate to steal an advantage; for others, it is trivial. This paper explores the contradictions and tensions of the author’s experience of how sport and PE students talk about ‘race’ and racism. ‘Race’ talk is considered here in the context of passive everyday ‘race’ talk, dominant discourses in sporting cultures, and colour blindness.

Theoretical framework: Drawing on Guinier and Torres’ [2003. The Miner's Canary: Enlisting Race, Resisting Power, Transforming Democracy. London: Harvard University Press] ideas of resistance through political race consciousness and Bonilla-Silva’s [2010. Racism Without Racists: Colour-Blind Racism and the Persistence of Racial Inequality in the United States. Plymouth: Rowan and Littlefield] notion of colour blindness, the semantics of ‘race’ and racialisation in sport and PE are interrogated through the prism of critical race theory (CRT). CRT is used here to centre ‘race’ and racialised relations where disciplines have consciously or otherwise excluded them. Importantly, the centring of ‘race’ by critical race scholars has advanced a strategic and pragmatic engagement with this slippery concept that recognises its paradoxical but symbolic location in society.

Discussion: Before exploring ‘race’ talk in the classroom, using images from the sport media as a pedagogical tool, the paper considers how ‘race’ is recreated and renewed. The paper then turns to explore how the effortless turn to everyday ‘race’ talk in the classroom can be viewed as an opportunity to disrupt racialised assumptions with the potential to implicate those that passively do so. Further, the diagnostic, aspirational, and activist goals of political race consciousness are established as vehicles for a positive sociological experience in the classroom.

Conclusion: The work concludes with a consideration of the uses and dangers of passive ‘race’ talk and the value of a political race consciousness in sport and PE. Part of the explanation for the perpetuation of ‘race’ talk and the relative lack of concern with its impact on education and wider society is focused on how the sovereignty of sport and PE trumps wider social concerns of ‘race’ and racism because of at least four factors: (1) the liberal left discourses of sporting utopianism, (2) the ‘race’ logic that pervades sport, based upon the perceived equal access and fairness of sport as it coalesces with the (3) ‘incontrovertible facts’ of black and white superiority (and inferiority) in certain sports, ergo the racial justifications for patterns of activity in sport and PE, and (4) the racist logic of the Right perpetuated through a biological reductionism in sport and PE discourses.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号