Similarities and differences among half-marathon runners according to their performance level

This study aimed to identify the similarities and differences among half-marathon runners in relation to their performance level. Forty-eight male runners were classified into 4 groups according to their performance level in a half-marathon (min): Group 1 (n = 11, < 70 min), Group 2 (n = 13, < 80 min), Group 3 (n = 13, < 90 min), Group 4 (n = 11, < 105 min). In two separate sessions, training-related, anthropometric, physiological, foot strike pattern and spatio-temporal variables were recorded. Significant differences (p<0.05) between groups (ES = 0.55–3.16) and correlations with performance were obtained (r = 0.34–0.92) in training-related (experience and running distance per week), anthropometric (mass, body mass index and sum of 6 skinfolds), physiological (VO2max, RCT and running economy), foot strike pattern and spatio-temporal variables (contact time, step rate and length). At standardized submaximal speeds (11, 13 and 15 kmh-1), no significant differences between groups were observed in step rate and length, neither in contact time when foot strike pattern was taken into account. In conclusion, apart from training-related, anthropometric and physiological variables, foot strike pattern and step length were the only biomechanical variables sensitive to half-marathon performance, which are essential to achieve high running speeds. However, when foot strike pattern and running speeds were controlled (submaximal test), the spatio-temporal variables were similar. This indicates that foot strike pattern and running speed are responsible for spatio-temporal differences among runners of different performance levelThis work was supported by the Spanish Sports Council (CSD) under the project 157/UPB10/12, by a grant of the High Sport Performance Centre of León (CAR-León); and by the Basque Country Government, under a predoctoral grant number reference PRE_2013_1_1109 (J.G.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Similarities and differences among half-marathon runners according to their performance level

This study aimed to identify the similarities and differences among half-marathon runners in relation to their performance level. Forty-eight male runners were classified into 4 groups according to their performance level in a half-marathon (min): Group 1 (n = 11, < 70 min), Group 2 (n = 13, < 80 min), Group 3 (n = 13, < 90 min), Group 4 (n = 11, < 105 min). In two separate sessions, training-related, anthropometric, physiological, foot strike pattern and spatio-temporal variables were recorded. Significant differences (p<0.05) between groups (ES = 0.55–3.16) and correlations with performance were obtained (r = 0.34–0.92) in training-related (experience and running distance per week), anthropometric (mass, body mass index and sum of 6 skinfolds), physiological (VO2max, RCT and running economy), foot strike pattern and spatio-temporal variables (contact time, step rate and length). At standardized submaximal speeds (11, 13 and 15 kmh-1), no significant differences between groups were observed in step rate and length, neither in contact time when foot strike pattern was taken into account. In conclusion, apart from training-related, anthropometric and physiological variables, foot strike pattern and step length were the only biomechanical variables sensitive to half-marathon performance, which are essential to achieve high running speeds. However, when foot strike pattern and running speeds were controlled (submaximal test), the spatio-temporal variables were similar. This indicates that foot strike pattern and running speed are responsible for spatio-temporal differences among runners of different performance levelThis work was supported by the Spanish Sports Council (CSD) under the project 157/UPB10/12, by a grant of the High Sport Performance Centre of León (CAR-León); and by the Basque Country Government, under a predoctoral grant number reference PRE_2013_1_1109 (J.G.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

El uso de fotocélulas de haz simple y doble para medir la velocidad en carreras®. The use of single- and dual-beam photocells to measure the sprint time®.

Resuemn<p align="justify">El objetivo del estudio fue analizar la influencia de la tecnología de las fotocélulas en el registro de tiempo y su fiabilidad durante de carreras de velocidad de corta distancia. Participaron 25 estudiantes (20.5±0.5 años; 1.78±0.02 m; 77.5±1.8 kg) que fueron evaluados en 3 días (2 de familiarización y 1 de test). Se registraron aleatoriamente 3 carreras de aceleración y 3 velocidad lanzada, cronometradas simultáneamente a los 5, 10 y 15 m por dos sistemas de fotocélulas DSD Laser System®: haz simple y doble haz. El tipo de fotocélulas utilizadas influyó en el tiempo de carrera (F=11.92 y p<0.001) y su fiabilidad (F=14.52 y p<0.001). En la carrera de aceleración el haz simple sobrestimó ~0.02 s el tiempo respecto al doble haz (F=42.95 y p<0.001), obteniéndose registros fiables (CCI > 0.80) a los 10 y 5 m, respectivamente. En la carrera lanzada ambos sistemas midieron prácticamente igual (diferencias de ~0.005 s), obteniendo registros fiables a los 15 y 10 m, respectivamente. En conclusión, en carreras de aceleración la distancia mínima a registrar con haz simple debe ser de 10 m, y de 5 m con haz doble, mientras que en carreras lanzadas deberían utilizarse unas distancias mínimas de 15 y 10 m, respectivamente. Futuros estudios deberían analizar la distancia óptima a la primera fotocélula en las carreras de aceleración, para aumentar la fiabilidad de la medición y facilitar la comparación entre registros de diferentes estudios.</p>Abstract<p align="justify">The purpose was to analyze the influence of the timing gates’ technology on both running time performance and its reliability during short sprint distances. Twenty-five physical students participated (20.5±0.5 yr; 1.78±0.02 m; 77.5±1.8 kg), whose were evaluated during 3 separate days (2 familiarization sessions and 1 testing session). Three standing-start and 3 flying-start runs were randomized and simultaneously registered at 5, 10 and 15 m by two timing gates DSD Laser System®: single- and dual-beam. The type of timing gates affected the performance (F=11.92 y p<0.001) and the reliability (F=14.52 y p<0.001). During the standing-start runs, the single-beam system overestimated (~0.02 s) the performance with respect to the dual-beam one (F=42.95 y p<0.001), and the reliability was acceptable (CCI>0.80) at the distances of 10 and 5 m, respectively. During the flying-start runs, both systems obtained a very similar registry (differences of ~0.005 s), and the reliability was acceptable at the distances of 15 and 10 m, respectively. In conclusion, during the standing-start runs the minimum distance to registry the performance with a single-beam system should be 10 m, and 5 m with a dual-beam system. During the flying-start runs these distances should be 15 and 10 m, respectively. Further studies should analyze the optimal distance to the first timing gate during the standing-start runs, in order to improve the reliability and to compare the performances which were obtained in different studies.</p