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1.
In this study, we examined aspects of the 4 2 100 m relay that are amenable to mathematical analysis. We looked at factors that affect the time required to complete the relay, focusing on the performance of elite male athletes. Factors over which the individual athletes, and the team coach, can exercise some control are: the starting positions of the runners on legs 2, 3 and 4, the positions at which baton exchanges occur, the free distances at the baton exchanges and the running order of the athletes. The lane draw is shown to have an important influence on the relay time, although it is outside the control of the team coach. Teams drawn in the outside lanes benefit from the inverse relation between bend radius of curvature and running speed. For teams composed of athletes with different times over 100 m, we show that the fastest relay times are achieved with the fastest athlete taking the first leg, with the slowest two runners allocated to the final two legs. 相似文献
2.
A.J. Ward-Smith 《Journal of sports sciences》2013,31(9):701-710
The aims of this study were to examine energy conversion strategies during 100 m sprinting and to determine whether there are opportunities for performance enhancement beyond the usual ‘maximum effort throughout’ strategy. The roles of aerodynamic drag and kinetic energy recovery on the overall whole-body energy balance are discussed. A mathematical model based on sprinting with maximum effort, converting chemical energy as rapidly as possible to mechanical energy, is used to calculate a reference performance. Subsequent calculations show the effect of inserting a period of constant-speed running on overall running time. The paper explores how the timing of entry into the second phase affects the overall running time. Overall, the calculations show that no benefits result from adopting a running strategy involving the insertion of a constant-speed phase; the analysis confirms that the strategy of running with maximum effort is the optimum. For a certain range of conditions, the insertion of a short period of constant-speed running has been shown to have a negligible effect on overall running time. For elite male athletes, the constant-speed phase may be entered between 55 and 60 m from the start line, while for elite female athletes the corresponding values are between 46 and 53 m from the start. 相似文献
3.
Using mathematical analysis, we examined the three baton exchanges that occur during a 4 x 100 m relay. Identical representative 100 m running performances were assumed for each of four elite male athletes, and the calculations were made for optimal or near-optimal positions of the baton exchanges and starting positions of the athletes running the second, third and fourth legs as determined by Ward-Smith and Radford (2002). In this paper, we focus on the calculation of the checkmark position and demonstrate the complexity of the baton exchange process. The results of the mathematical analysis show that, for optimal performance, the checkmark should be located differently for each of the three exchanges in a single race, and is further affected bylane draw and free distance (the distance between the runners at the baton exchange). For a representative free distance of 1 m at each exchange, the checkmark distance ranges from a minimum of 11.04 m at the third exchange in Lane 1 to 12.20 m for the first exchange in Lane 8. Failure by teams and their coaches to consider adequately the complexities of the baton exchanges may help explain why 25.5% of teams in recent World Championships were disqualified or did not finish. 相似文献
4.
Ward-Smith AJ 《Journal of sports sciences》2001,19(9):701-710
The aims of this study were to examine energy conversion strategies during 100 m sprinting and to determine whether there are opportunities for performance enhancement beyond the usual 'maximum effort throughout' strategy. The roles of aerodynamic drag and kinetic energy recovery on the overall whole-body energy balance are discussed. A mathematical model based on sprinting with maximum effort, converting chemical energy as rapidly as possible to mechanical energy, is used to calculate a reference performance. Subsequent calculations show the effect of inserting a period of constant-speed running on overall running time. The paper explores how the timing of entry into the second phase affects the overall running time. Overall, the calculations show that no benefits result from adopting a running strategy involving the insertion of a constant-speed phase; the analysis confirms that the strategy of running with maximum effort is the optimum. For a certain range of conditions, the insertion of a short period of constant-speed running has been shown to have a negligible effect on overall running time. For elite male athletes, the constant-speed phase may be entered between 55 and 60 m from the start line, while for elite female athletes the corresponding values are between 46 and 53 m from the start. 相似文献
5.
Our aims were to improve our understanding of human performance before 1850 and to put nineteenth- and twentieth-century performances into a broader historical context. Consequently, 536 foot-races performed in Britain in the 'long' eighteenth century were identified, 53 of which were analysed in detail. The best performances at the end of the eighteenth century were compared with those at the end of the nineteenth and twentieth centuries. The data for the nineteenth century were marginally better than those for the eighteenth century up to 20 km, but beyond that Thomas Carlisle's time, set in about 1740, of 2 hours for 21 miles was outstanding. Current records are shown to be better than earlier records at all distances from 5 km up to the marathon, the superiority being most pronounced from 15 km upwards. 相似文献
6.
Using mathematical analysis, we examined the three baton exchanges that occur during a 4×100 m relay. Identical representative 100 m running performances were assumed for each of four elite male athletes, and the calculations were made for optimal or near-optimal positions of the baton exchanges and starting positions of the athletes running the second, third and fourth legs as determined by Ward-Smith and Radford (2002). In this paper, we focus on the calculation of the checkmark position and demonstrate the complexity of the baton exchange process. The results of the mathematical analysis show that, for optimal performance, the checkmark should be located differently for each of the three exchanges in a single race, and is further affected by lane draw and free distance (the distance between the runners at the baton exchange). For a representative free distance of 1 m at each exchange, the checkmark distance ranges from a minimum of 11.04 m at the third exchange in Lane 1 to 12.20 m for the first exchange in Lane 8. Failure by teams and their coaches to consider adequately the complexities of the baton exchanges may help explain why 25.5% of teams in recent World Championships were disqualified or did not finish. 相似文献
7.
In this study, we examined aspects of the 4 x 100 m relay that are amenable to mathematical analysis. We looked at factors that affect the time required to complete the relay, focusing on the performance of elite male athletes. Factors over which the individual athletes, and the team coach, can exercise some control are: the starting positions of the runners on legs 2, 3 and 4, the positions at which baton exchanges occur, the free distances at the baton exchanges and the running order of the athletes. The lane draw is shown to have an important influence on the relay time, although it is outside the control of the team coach. Teams drawn in the outside lanes benefit from the inverse relation between bend radius of curvature and running speed. For teams composed of athletes with different times over 100 m, we show that the fastest relay times are achieved with the fastest athlete taking the first leg, with the slowest two runners allocated to the final two legs. 相似文献
8.
Computed results from a mathematical model of the bioenergetics of sprinting, which incorporates a three-equation representation of anaerobic metabolism, were compared with measured distance-time data for female athletes from the finals of the 100-m event at the World Championships of 1987. The computed results closely model the performance of the competitors over the course of the entire race. The three main contributions to anaerobic metabolism were investigated and comparisons were made between male and female sprinters. Whereas the time constants for adenosine triphosphate (ATP) and phosphocreatine utilization for the two sexes were found to be similar, for oxygen-independent glycolysis the time constants of the female athletes were found to be higher. The maximum powers generated by female athletes during ATP conversion and glycolysis were only slightly lower than the figures found for male athletes, but the value for phosphocreatine utilization was substantially lower. The lower value for phosphocreatine utilization might explain the more pronounced fall-off in running speed over the latter stages of a race that female athletes experience in comparison with men. Although anaerobic sources dominate energy provision for both male and female sprinters, the calculations show that the latter make greater use of aerobic energy supplies. 相似文献
9.
Our aims were to improve our understanding of human performance before 1850 and to put nineteenth- and twentieth-century performances into a broader historical context. Consequently, 536 foot-races performed in Britain in the 'long' eighteenth century were identified, 53 of which were analysed in detail. The best performances at the end of the eighteenth century were compared with those at the end of the nineteenth and twentieth centuries. The data for the nineteenth century were marginally better than those for the eighteenth century up to 20 nm, but beyond that Thomas Carlisle's time, set in about 1740, of 2 hours for 21 miles was outstanding. Current records are shown to be better than earlier records at all distances from 5 km up to the marathon, the superiority being most pronounced from 15 km upwards. 相似文献
10.
A J Ward-Smith 《Journal of sports sciences》1999,17(4):325-334
Here, a new mathematical model of sprinting is proposed. The prediction method rests on the construction of an energy balance incorporating a mathematical representation of each of the major terms in the balance. The term expressing the degradation of mechanical energy into thermal energy is formulated to express a dependence on wind speed. The dependence of the drag term on the change in mean body angle relative to the horizontal is taken into account. Whereas the effect of modifying the degradation term is shown to be significant, changes in body lean angle are shown to have little effect. Comparisons of the present predictions with a previous statistical analysis of 100-m track data show good agreement. Sensitivity analyses show which variables have the greatest influence on sprinting performance. 相似文献