Usages and meanings associated with three key cultural metaphors, "outlaw," "family," and "community" are examined in order to determine the limits of their applicability within American sprint car racing, and to provide a clearer understanding of the cultural significance of sprint car racing in America. These three metaphors have multiple functions. They are used to structure relationships, communicate codes of conduct, express attitudes, and enculturate participants.The sprint car racing "community" is outside the mainstream of sport culture in America, and it is at once metaphoric, ideal, and real. Culture provides participants with a range of possible mechanisms for structuring, organizing, and communicating the value system(s) and symbolic system(s) involved in the construction and racing of sprint cars. Sprint car racing in America provides an outlet for a preferred way of life in which competitive behavior is a major aspect. Cooperation with those whom you are competing against functions to reinforce the values of the "community." / Department of Anthropology

As early as 1994, and with transformation in mind, the African National Congress (ANC) identified the development of the previously disadvantaged communities in South Africa as a national priority. In so doing, sport, among others, was used in this strategy as a medium to improve and change the circumstances of people in disadvantaged communities. Sports development in disadvantaged communities is essential, if taken into consideration that without such further support of the sport talent of some of these children, the needs of these talented children cannot be met and their potential will remain undeveloped. Talent identification (TID), which is based on scientific principles and forms the first step in sports development, still is relatively new in South Africa. Historically, coaches used their own knowledge and experience of the characteristics, which should lead to success in sport as well as participation in competitions in order to do TID. To date, very little research has been done on talent identification and development in sprints and long-jump, especially pertaining to young boy and girl athletes, and in particular concerning athletes from disadvantaged communities. The first and second objectives of this study were to implement sport specific athletics development programmes aimed at improving sprinting and long-jump ability and to determine its effect on the abilities and skills of talented 10 to 15 year-old girls and boys with talent for sprints and long-jump. The third and fourth objectives of this study were to establish which kinanthropometric, physical and motor components will play such a role in 10 to 15 year-olds that it can predict performance ability in sprints and long-jump in girls and boys at this age. The "Australian Talent Search" protocol was used to identify general sport talent in the children (66 girls and 62 boys) who were identified for the study. The talented children (19 girls and 21 boys) from the initial group of were then subjected to a sport specific test battery for sprints and long-jump. The maturation level of the boys was determined by means of a maturity questionnaire, based on the 5 Tanner stages. By using the Statistica and SAS computer programmes, independent t-testing, covariance analyses, correlation coefficients, effect sizes, descriptive statistics as well as a stepwise multiple regression analysis were used to analyze the data with regard to the above-mentioned objectives. A p-value smaller than or equal to 0.05 was accepted as significant. From the results of the study it is evident that the development programmes contributed to the improvement of physical and motor abilities and skills important for performance in both sprints and long-jump in girls (n=19) and boys (n=21) respectively. Among the girls, flexibility, explosive power, muscle endurance, reaction time, speed, speed endurance, acceleration and long-jump showed statistically significant improvement, while abdominal muscle strength and stride length showed no improvement. Secondly, it was established that the development programme contributed statistically significantly to an improvement in flexibility, muscle endurance, 0-40 metres speed and long-jump ability in boys. However, some components did not show improvement, among them explosive power, reaction time, speed endurance, acceleration and stride length. A stepwise multiple regression analysis was used to analyze the third and fourth objectives. It indicated that, in respect to the 100 metres sprint, 7 variables, namely long-jump, push-ups to the point of exhaustion, 7-level abdominal strength, 0-5 metres speed, ankle dorsiflexion, body length and age contributed 84.0% to the total variance in girls. As for long-jump, 7 variables, namely 0-100 metres speed, body length, 7-level abdominal strength, push-ups, ankle dorsiflexion, standing long-jump and body mass proved to be the most important contributors to performance in these items with a total contribution of 79% to the total variance. The fourth objective indicated that average anaerobic power output, acceleration and body mass contributed statistically significantly to performance in the 100 metres sprint in boys with a contribution of 86.5% to the total variance. Horizontal jump, age and acceleration contributed statistically significantly to long-jump performance with a contribution of 81 5% to the total variance. It is evident from this study that sport specific development programmes can successfully be implemented on girls and boys at ages 10-15 in order to improve sprinting and long-jump ability, regardless of poverty-stricken circumstances and poor infrastructure. Furthermore, the study brought to light that specific kinanthropometric, physical and motor abilities exist which can be used to predict performance in sprints and long-jump in girls and boys separately at ages 10 to 15. / Thesis (Ph.D. (Human Movement Science))--North-West University, Potchefstroom Campus, 2007

Performance and exercise capacity in prolonged continuous exercise has been shown to be enhanced by the ingestion of dilute (-6%) carbohydrate-electrolyte (CHO-E) solutions during exercise. There is a wealth of literature on the effects of CHO-E solutions on prolonged, continuous exercise however this is not the case for highintensity intermittent exercise. One reason for this is the difficulty of replicating the demands of multiple-sprint sports within the laboratory. The development of the Loughborough Intermittent Shuttle Running Test (LIST), a protocol that simulates the physiological demand of multiple-sprint sports, has allowed for further study in this area. Sports drinks contain a variety of different types of carbohydrate, including synthetic polymers of maltodextrins. The rationale for these is two-fold; firstly there is some evidence to suggest that these glucose polymers of low osmolality may empty faster than isoenergetic glucose solutions especially at dilute (-6%) concentrations. Secondly CHO-E solutions formulated from maltodextrins with low dextrose equivalents are less acidogenic and have lower cariogenic potential than simple glucose solutions, thus making them preferable for tooth health. Therefore the purpose of this thesis was to examine the effects of a 6.4% hypotonic synthetic polymer maltodextrin CHO-E solution on muscle metabolism and physiological performance during prolonged high-intensity intermittent running (LIST). This thesis contains four experimental studies. From the results of study 1 it was concluded that the ingestion of a 6.4% hypotonic CHO-E solution provided no ergogenic benefit to running capacity during the LIST despite blood and hormonal data suggesting that the solution was effective at delivering glucose. As isotonic CHO-E solutions have shown to have ergogenic properties during LIST running the purpose of study 2 was to compare isoenergetic hypotonic and isotonic CHO-E solutions during LIST running. The results from this study suggested that performance, as measured by exercise capacity and sprint speed, was not affected by either treatment. In study 3 the protocol was modified to extend the exercise duration so that a greater demand was placed on the subjects' glycogen reserves. The results from this study further confirmed that exercise capacity in LIST running was not influenced by CHO provision during exercise however the habitual CHO intake of the subjects may have masked any ergogenic properties of the CHO-E solution and led to increased performance in the control trials. In the final study the subjects' pre-trial exercise and dietary CHO intake was manipulated to increase endogenous glycogen concentrations. The results showed that in these subjects the ingestion of a 6.4% hypotonic CHO-E solution increased exercise capacity during the LIST by 21%. Muscle biopsy analyses revealed a lower net muscle glycogen utilisation in the CHO trial post-90 min (p=0.07). There is evidence in the literature to suggest that there is an ergogenic effect of CHO ingestion during the LIST. However the results presented in this thesis suggest that when endogenous glycogen stores are moderate the ingestion of a CHO-E solution may suppress lipid oxidation without a concomitant increase in CHO oxidation and thus LIST capacity is not enhanced. In contrast, when endogenous glycogen concentrations are elevated through dietary manipulation there is an ergogenic benefit from the ingestion of hypotonic CHO-E solutions during LIST exercise.

Past research on the acceleration phase in sprint running has concentrated on the kinematics of sprint blocks set-up and the initial steps after exiting the sprint blocks. In contrast, there has been limited research on the ground reaction forces (GRF) generated during the initial post-block foot contacts. These initial foot contacts in sprinting are important for optimising performance in the initial acceleration phase of sprinting. However, little is known about the GRF elite sprinters generate during the initial foot contacts and how these GRF characteristics relate to performance. It is the anterior-posterior (A-P) GRF that are of most importance as they indicate the sprinter’s motion from the start to the finish line. This thesis investigates the A-P GRF of the first two foot contacts of the sprint start after leaving the blocks. The participants included seventeen male and six female sprinters with a mean age of 22.6 (SD 4.4 years). Seventeen of the sprinters had competed at international/national level competitions and six at recreational/amateur level competitions. The athletes were classified as senior male elite (SME), senior female elite (SFE), junior male elite (JME) and senior male recreational (SMR). The sprinters were instructed to perform block starts at maximal effort to produce the fastest time over 5 metres on a 30 metre indoor laboratory track. Timing gates were used to record 5 metre times and two strain gauge force plates were placed in series to collect GRF data from the first two foot contacts after leaving the starting blocks. From the GRF data, braking time, maximum A-P braking force, A-P braking impulse, propulsive time, maximum A-P propulsive force, A-P propulsive impulse and A-P contact impulse were determined for each trial. The A-P propulsive phase constituted greater than 90% of the total contact time, had approximately twice the magnitude of the maximum force of the braking phase and accounted for more than 95% of the total contact impulse across the four groups of sprinters. The SME group produced a significantly larger A-P propulsive impulse on the first and second steps compared to the SFE (p less than 0.05 and p less than 0.05 respectively), JME (not significant and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s maximum A-P propulsive force was significantly larger on the first and second steps than the SFE (p less than 0.05 and p less than 0.05 respectively), JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s propulsive time on the first and second steps was not significantly different compared to the SFE (both not significant) but was significantly shorter compared to the JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The maximum A-P propulsive force correlated strongly with 5 metre time for the first step (rs = -0.670, p less than 0.01), second step (rs = -0.621, p less than 0.01) and the addition of the first and second steps (rs = -0.678, p less than 0.01) across all the sprinters. Whereas, the A-P propulsive impulse correlated strongly with 5 metre time for the first step (rs = -0.525, p less than 0.01), second step (rs = -0.592, p less than 0.01) and the addition of the first and second steps (rs = -0.584, p less than 0.01). Three A-P GRF patterns were observed during the first and second foot contacts of the sprinters examined in this study. A braking-propulsive (B-P) pattern was the most frequently observed followed by a propulsive-braking-propulsive (P-B-P) and a no braking (NB) pattern 82.7%, 15.4% and 1.9% respectively. The P-B-P and NB patterns, which have not been described previously, appeared most frequently in the least experienced sprinters. In the past, some sprinters and their coaches have tried to minimise the braking phase and maximise the propulsive phase of the first two foot contacts after exiting the blocks during sprinting. This study suggests that increasing the maximum propulsive force is the best way to increase performance over the first 5 metres of the acceleration phase. The research also suggests that there will be little benefit gained from trying to increase performance by focusing on the braking phase during these first two steps after exiting the blocks. As such, sprinters and coaches should focus their attention primarily on producing a large A-P propulsive force during the first two steps of a sprint.

Past research on the acceleration phase in sprint running has concentrated on the kinematics of sprint blocks set-up and the initial steps after exiting the sprint blocks. In contrast, there has been limited research on the ground reaction forces (GRF) generated during the initial post-block foot contacts. These initial foot contacts in sprinting are important for optimising performance in the initial acceleration phase of sprinting. However, little is known about the GRF elite sprinters generate during the initial foot contacts and how these GRF characteristics relate to performance. It is the anterior-posterior (A-P) GRF that are of most importance as they indicate the sprinter’s motion from the start to the finish line. This thesis investigates the A-P GRF of the first two foot contacts of the sprint start after leaving the blocks. The participants included seventeen male and six female sprinters with a mean age of 22.6 (SD 4.4 years). Seventeen of the sprinters had competed at international/national level competitions and six at recreational/amateur level competitions. The athletes were classified as senior male elite (SME), senior female elite (SFE), junior male elite (JME) and senior male recreational (SMR). The sprinters were instructed to perform block starts at maximal effort to produce the fastest time over 5 metres on a 30 metre indoor laboratory track. Timing gates were used to record 5 metre times and two strain gauge force plates were placed in series to collect GRF data from the first two foot contacts after leaving the starting blocks. From the GRF data, braking time, maximum A-P braking force, A-P braking impulse, propulsive time, maximum A-P propulsive force, A-P propulsive impulse and A-P contact impulse were determined for each trial. The A-P propulsive phase constituted greater than 90% of the total contact time, had approximately twice the magnitude of the maximum force of the braking phase and accounted for more than 95% of the total contact impulse across the four groups of sprinters. The SME group produced a significantly larger A-P propulsive impulse on the first and second steps compared to the SFE (p less than 0.05 and p less than 0.05 respectively), JME (not significant and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s maximum A-P propulsive force was significantly larger on the first and second steps than the SFE (p less than 0.05 and p less than 0.05 respectively), JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME group’s propulsive time on the first and second steps was not significantly different compared to the SFE (both not significant) but was significantly shorter compared to the JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The maximum A-P propulsive force correlated strongly with 5 metre time for the first step (rs = -0.670, p less than 0.01), second step (rs = -0.621, p less than 0.01) and the addition of the first and second steps (rs = -0.678, p less than 0.01) across all the sprinters. Whereas, the A-P propulsive impulse correlated strongly with 5 metre time for the first step (rs = -0.525, p less than 0.01), second step (rs = -0.592, p less than 0.01) and the addition of the first and second steps (rs = -0.584, p less than 0.01). Three A-P GRF patterns were observed during the first and second foot contacts of the sprinters examined in this study. A braking-propulsive (B-P) pattern was the most frequently observed followed by a propulsive-braking-propulsive (P-B-P) and a no braking (NB) pattern 82.7%, 15.4% and 1.9% respectively. The P-B-P and NB patterns, which have not been described previously, appeared most frequently in the least experienced sprinters. In the past, some sprinters and their coaches have tried to minimise the braking phase and maximise the propulsive phase of the first two foot contacts after exiting the blocks during sprinting. This study suggests that increasing the maximum propulsive force is the best way to increase performance over the first 5 metres of the acceleration phase. The research also suggests that there will be little benefit gained from trying to increase performance by focusing on the braking phase during these first two steps after exiting the blocks. As such, sprinters and coaches should focus their attention primarily on producing a large A-P propulsive force during the first two steps of a sprint.

[Truncated abstract] The inclusion of a warm-up in the form of prior exercise (PE) is generally advocated as a preparatory strategy of choice to improve sprint performance. Although there is evidence that both increasing muscle temperature and mobilising the cardiorespiratory system prior to exercise contribute largely to the benefit of PE on sprint performance, their relative importance is unknown. Another important question relates to situations where an athlete has to engage in a sprint shortly after one or several earlier sprints. Under these conditions, is engaging in mild exercise also the most effective preparatory strategy to adopt prior to sprinting when performed after a previous sprint(s)? It was the primary aim of this thesis to address these questions. Firstly, we hypothesised that there is a temporal shift in the mechanisms responsible for the effect of PE on power output during a maximal sprint effort, with temperature-dependent mechanisms playing a more important role at the onset of the sprint and mobilisation of the cardiorespiratory system playing a more important role later. To test this hypothesis, we compared the responses of a 30-s sprint to different PE protocols designed to control for either muscle temperature or pre-exercise VO2. ... A group of trained athletes was subjected to four consecutive bouts of 30-s sprint, each separated by 20 min of either active recovery at 40% VO2 peak or passive recovery. Our results show that PP, MP-20 and MP-10 did not fall between the first and last sprints, and were not affected by active recovery. In contrast, we found that MP10 and MP30 decrease significantly between the first and last sprint of the passive recovery trial, but not when active recovery is performed between consecutive sprints. Finally, this study also showed that the fall in mean power associated with repeated 30-s sprints in the passive recovery trial resulted primarily from a fall in early, but not late power output. These findings show that the early and late mean power output of repeated sprints respond differently to active and passive recovery, with the decrease in total mean power with repeated 30-s sprints resulting primarily from a fall in early as opposed to either late power output or peak power, thus highlighting the benefit of active recovery as a favourable preparatory strategy for the performance of repeated sprints of short (<10s) or longer duration (<30s), but not for repeated peak power.

Abstract Aim was to investigate the effects of heavy resisted and unresisted sprint training protocols and see its effects on sprint time, vertical and horizontal jumping and sprint mechanics. Youth male soccer players [n=27] participated in this study, they were all individually assessed for the horizontal force-velocity profile using two unresisted sprints and load-velocity profile using four progressively resisted sprints (25%, 50%, 75% and 100% body mass). For all sprints an isotonic braking device was used. They also performed vertical and horizontal jumps, counter-movement jump (CMJ) was used for the former and standing long jump (SLJ) for the latter. They were put in three groups (RST: resisted sprint training; UST: unresisted sprint training and TAU: control group – “training as usual”). Athletes performed a 4-week training intervention (5x20m resisted sprint group; 8x20m unresisted sprint group) and were tested 7 days after completing their final training session. Only RST improved all sprint times (T30, T20, T10, T5) substantially (-4.2% to -7.9% in split times) and provided trivial or small changes in sprint mechanics. The small changes were seen in sprint mechanical parameters of RFmax, Pmax and F0. UST only showed trivial effects in those parameters, while TAU showed a small decrease in both Pmax and Vmax. Regarding the jumps, RST and UST both showed a small increase in standing long jump and a trivial effect in counter-movement jump, while TAU decreased in both. Main conclusion is that resisted sprinting has proven to be a worthwhile method to improve acceleration and sprint performance and can be used by practitioners across a wide array of sports. It also improved jumping performance and sprint mechanical outputs, which point toward an improvement in better application of force in a horizontal direction.

This doctoral thesis deals with the kinesiological analysis of the athletic run - sprint. The aim of the thesis is the time characteristics comparison and switching on of the muscles which are working during the sprint before and after the performance of special running exercises. It is becoming much more important to use the special training procedures during training sessions. The special running exercises are performed almost daily during training sessions of sprinters. The question is to what extent their performance is evident on the activation of muscles. The qualitative and quantitative results show the activation of muscles during sprint before and after the performance of the special running exercises. The main tool of the research was the surface EMG analysis of muscles during a 30-metre long sprint. The content of the research were two comparative analysis, where 8 proband participated - interindividual and intraindividual. During the evaluation process we considered the quantitative and qualitative components. On the basic of the reached results we may say that there is no diference between the run before and after the performance of special running exercises. Keywords: Sprint, special running exercises, electromyography, ANOVA

Made available in DSpace on 2015-12-06T23:47:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2008 / Ministerio de Desarrollo y Planificación del Estado de Chile” (MIDEPLAN) / Este trabalho propõe dois modelos de regressão múltipla que explicam variáveis do Teste de Velocidade por meio do Teste de Wingate e variáveis relacionadas ao peso corporal. Existem múltiplos fatores que influenciam o desempenho anaeróbio, porém é menos conhecida a respeito da relação quantitativa e valor predictivo de variáveis obtidas no Teste de Wingate e variáveis obtidas em campo. Foram avaliados 43 futebolistas adolescentes brasileiros de elite, divididos em 2 grupos de (15-16 e 17-18 anos). Mensurou-se o peso, a estatura, a porcentagem de massa gorda e desempenho anaeróbio através do teste de Wingate e Teste de Velocidade em campo em 220m. Os modelos foram significantes para as variáveis de velocidade inicial e aceleração mediana em campo com um valor de R2 de 0,34 e 0,47 (p < 0,05), respectivamente. Foi possível compor variáveis do Teste de Velocidade em campo a partir de variáveis obtidas no Teste de Wingate corrigidas por variáveis associadas ao peso por meio de um modelo matemático. / This study proposes two multiple regression models that explain variables of the Sprint Test through the Wingate Test and variables related to body weight. There are multiple factors that influence anaerobic performance; however, it is less known about the quantitative relation and predictive value of variables obtained in the Wingate Test obtained in field. Forty three Brazilian adolescent elite soccer players, divided into 2 groups of aged 15-16 and aged 17-18. Weight, height, fat mass percentage and anaerobic performance with the Wingate Test and the Sprint Test in 220m were measured. The models were significant for the initial speed and median acceleration in field with an R2 value of 0.34 and 0.47 (p < 0.05), respectively. Sprint test in field variables could be composed from the variables obtained with the Wingate Test adjusted by variables associated to the weight through a mathematical model. / BV UNIFESP: Teses e dissertações

Various aspects of performance (e.g., sprint speed, grip strength) are thought to be important determinants of the success of animals in natural activities such as foraging, mating, and escaping from predators. However, it is generally known that morphological properties enhancing one type of performance (e.g., speed) can lead to a reduction in another (e.g., strength). Such performance trade-offs have been quantified at the inter-specific level, but evidence at the inter-individual level remains equivocal. To test for the presence of a performance trade-off, I initiated a study on wild white-footed mice (Peromyscus leucopus). In summer 2016, I captured a total of 186 individuals, 87 of which were repeatedly phenotyped for grip strength and sprint speed. A significant positive relationship was found between body mass and grip strength (but not for sprint speed). Individual differences in performance were repeatable through time for both grip strength and sprint speed. Using a bivariate mixed model, I detected a significant negative correlation between grip strength and sprint speed at the among-individual level. By contrast, the within-individual correlation between grip strength and sprint speed tended to be positive, suggesting that some unquantified aspects of the mouse phenotype (e.g., body condition, age) may have a positive effect on both performance traits. Given the relatively low repeatability of grip strength and sprint speed, a failure to properly partition the correlation at the among- and within-individual level generates a counter-intuitive, positive correlation. This study is one the first to detect a performance trade-off at the among-individual level in a wild animal population.