Search

Background. Success in sprinting events broadly depends on many factors. Among them, the reaction time at starting is one of the main factors that help sprinters get success by increasing their confidence and helping to avoid false starts. Study purpose. The purpose of the study was to find out the relationship between reaction time and performance time among women finalist sprinters in six Olympic Games since 2000. Materials and methods. Data were collected from 227 (n = 227) women finalist sprinters in the event of 100 m (n = 47), 200 m (46), 400 m (43), 100 m H (45), and 400 m H (46) in 6 Olympic Games from 2000 to 2020, based on published official reports on "worldathletics.org" and "www.olympedia.org" websites. Data were considered from 227 samples from a total of 240 finalist women, where 13 were excluded because of a false start, being disqualified for doping, or failing to finish. Descriptive statistics, the Pearson correlation coefficient and simple regression analysis were used to determine the relationship between reaction time and performance time of the finalist women sprinters. The significance level was set at 0.05. Further Gaval'a 5-point scale was used to categorize the women sprinters based on their reaction times in five sprint events. Results. The results showed that there was a low positive correlation between reaction time and performance time among the sprinters in the 100 m (r = 0.369, p < 0.05) and 100m H (r = 0.367, p < 0.05) events, whereas no relation was confirmed in 200 m, 400 m and 400 m hurdles among women sprinters who participated in 2000-2020 Olympics. The 5-point scale revealed that 33.48% of sprinters belong to the average category, while 25.99% are in the unsatisfactory category, and only 1.32 % and 16.74% are in the excellent and very good categories, respectively. Conclusions. The current analysis concludes that there was a low positive relationship between reaction time and performance time of the finalist women sprinters only in sprint events of 100 m and 100 m hurdles during 2000 to 2020 Olympics, and the majority of the finalists belonged to the 'Average' category as per Gaval'a 5-point scale. [ABSTRACT FROM AUTHOR]

Background. Success in sprinting events broadly depends on many factors. Among them, the reaction time at starting is one of the main factors that help sprinters get success by increasing their confidence and helping to avoid false starts. Study purpose. The purpose of the study was to find out the relationship between reaction time and performance time among women finalist sprinters in six Olympic Games since 2000. Materials and methods. Data were collected from 227 (n = 227) women finalist sprinters in the event of 100m (n= 47), 200m (46), 400m (43), 100m H (45), and 400m H (46) in 6 Olympic Games from 2000 to 2020, based on published official reports on worldathletics.org and olympedia.org websites. Data were considered from 227 samples from a total of 240 finalist women, where 13 were excluded because of a false start, being disqualified for doping, or failing to finish. Descriptive statistics, the Pearson correlation coefficient and simple regression analysis were used to determine the relationship between reaction time and performance time of the finalist women sprinters. The significance level was set at 0.05. Further Gaval’a 5-point scale was used to categorize the women sprinters based on their reaction times in five sprint events. Results. The results showed that there was a low positive correlation between reaction time and performance time among the sprinters in the 100m (r = 0.369, p

Background: Sprinting is a type of running that consists of producing a short and intense effort in order to perform maximal speed in a short period of time. Sprinting is widely investigated because of the multiple and complex mechanisms involved. Sprint studies are now focusing on how to improve performance by focusing their analyses on the mechanic variables. The hamstrings are part of the most important muscle groups during sprinting because of their role of stabilization and propulsion, but they must be able to produce the maximum strength during a short moment, this ability is characterized by rate of torque development (RTD). The main of this study was to investigate the association between hamstring RTD (Nm.s -1 .kg- 1 ) and mechanical variables composed of maximal power output (Pmax) (W.kg -1 ), maximal theoretical velocity (V0) (m.s -1 ), and maximal horizontal force production (F0) (N.kg -1 ) on short sprints in elite sprinters., Methods: For this clinical trial, we used a research method based on data collection. A single group composed of four male and one female elite sprinters (age: 17.2 ± 1.79 years) has been included in this study. The sprinters performed a hamstring strength test, which included five trials of four seconds for each leg. This test required a portable dynamometer, the Kforce®, to collect 100 and 200 milliseconds RTD. Then the subjects were submitted to a sprint test. My Sprint® application has been used to collect the sprint mechanical variables. The sprint test included two trials; a starting block has been used for this test. A linear regression analysis was used between the rates of torque development and mechanical variables composed of maximal power output (Pmax) (W.kg -1 ), maximal theoretical velocity (V0) (m. s -1 ), and maximal horizontal force production (F0) (N.kg -1 )., Results: No significant correlation was observed between 100 and 200 ms hamstring RTD and sprint biomechanical variables: maximal power output (Pmax) (W.kg -1 ), maximal theoretical velocity (V0) (m. s -1 ), and horizontal force production (F0) (N.kg-1). However, 100 and 200 ms RTD collected on the dominant leg tends to be more correlated with maximal theoretical velocity (spearman's rho = 0.80; p-value = 0.13) and Pmax output (spearman's rho = 0.70; p-value = 0.23) while for non-dominant leg, RTD tends to be more correlated with maximal power output (spearman's rho = 0.60; p-value = 0.35) and horizontal force production (spearman's rho = 0.70; p-value = 0.23)., Conclusions: Hamstring RTD is not correlated with sprint biomechanical variables in elite sprinters. Further investigations must be made to study the observed trends in this study., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Commission Nationale de l'informatique et des libertés issued approval 2225099. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Moiroux--Sahraoui et al.)

The primary of the study was to identify relations between motor preparation and speed parameters in the group of experts-sprinters and in the group of novices-students. Interdependence was examined between speed and force factors and indicators of EMG movement structure: bioelectric muscle voltage and muscle activation timing. The participants were of 20 1st and 2nd sport class sprinters and a group of 35 students-novices. Force and jumping ability preparation tests were used in the study (standing long jump, standing triple jump and both feet jump with the use of Kistler platform), speed preparation test (30 m run from start block) and EMG signal recording. In the post-start phase, the sprinter's group was triggered lower limb muscle groups appropriate for the given sprint start phase (front muscle group: VL: vastus lateralis; RF: rectus femoris; GAS. MED.: gastrocnemius medialis and the back muscle group: STN: semitendinosus and BF: biceps femoris), while the student group demonstrated an advantage in activation of muscles of the upper limbs: BB: biceps brachii and TB: triceps brachii in the same phase. On the basis of the present research, a low start motion pattern was created, which enables proper selection of appropriate sprinter technique exercises. It has also been demonstrated that the effectiveness of sprinters' start technique is affected by factors from the area of coordination conditions. But in the group of students – the sprint start depends mainly on physical preparation (force-speed predispositions). [ABSTRACT FROM AUTHOR]

The objective of this study was to characterize the mechanics of maximal running sprint acceleration in high-level athletes. Four elite (100-m best time 9.95-10.29 s) and five sub-elite (10.40-10.60 s) sprinters performed seven sprints in overground conditions. A single virtual 40-m sprint was reconstructed and kinetics parameters were calculated for each step using a force platform system and video analyses. Anteroposterior force (FY), power (PY), and the ratio of the horizontal force component to the resultant (total) force (RF, which reflects the orientation of the resultant ground reaction force for each support phase) were computed as a function of velocity (V). FY-V, RF-V, and PY-V relationships were well described by significant linear (mean R2 of 0.892 ± 0.049 and 0.950 ± 0.023) and quadratic (mean R2 = 0.732 ± 0.114) models, respectively. The current study allows a better understanding of the mechanics of the sprint acceleration notably by modeling the relationships between the forward velocity and the main mechanical key variables of the sprint. As these findings partly concern world-class sprinters tested in overground conditions, they give new insights into some aspects of the biomechanical limits of human locomotion. [ABSTRACT FROM AUTHOR]

A new physical model of all-out sprinting is presented. The first models for the applied forces in the block, drive and maintenance phases, as well as for braking forces, are proposed and are based on experimental observations. The applied forces and the aerodynamic drag forces along with the speed and position of the sprinter are calculated by the model as functions of time. The model's unknown parameters are physically relevant and are quantitatively comparable to quantities measured experimentally. A novel mathematical method, not based on curve fitting, is proposed along with the model which requires two observable quantities, time of first step and start of maintenance phase, and four time splits. The model was validated by modeling several elite sprints from available split data, as well as measured splits for non-elite sprinters, over 100m and 200m distances. Excellent agreement between the split times and the simulated times was obtained and the model was shown to accurately predict 100m times from 60m splits for non-elite runners and 200m times from 100m splits for elite sprinters. The model was also applied to the study of wind and altitude effects for elite sprinters in 100 and 200m sprints. The model presented in this paper may also be useful as a coaching tool for non-elite sprinters by enabling comparisons with elite sprinters, the identification of weaknesses (comparing phases, braking coefficient) and by allowing predictions of 100m times based on 60m (indoor) performances and 200m times based on 100m splits. [ABSTRACT FROM AUTHOR]