RESUMEN
Understanding the changes in running mechanics caused by fatigue is essential to assess its impact on athletic performance. Changes in running biomechanics after constant speed conditions are well documented, but the adaptive responses after a maximal incremental test are unknown. We compared the spatiotemporal, joint kinematics, elastic mechanism, and external work parameters before and after a maximal incremental treadmill test. Eighteen recreational runners performed 2-minute runs at 8 km·h-1 before and after a maximal incremental test on a treadmill. Kinematics, elastic parameters, and external work were determined using the OpenCap and OpenSim software. We did not find differences in spatiotemporal parameters and elastic parameters (mechanical work, ankle, and knee motion range) between premaximal and postmaximal test conditions. After the maximal test, the runners flexed their hips more at contact time (19.4°-20.6°, P = .013) and presented a larger range of pelvis rotation at the frontal plane (10.3°-11.4°, P = .002). The fatigue applied in the test directly affects pelvic movements; however, it does not change the lower limb motion or the spatiotemporal and mechanical work parameters in recreational runners. A larger frontal plane motion of the pelvis deserves attention due to biomechanical risk factors associated with injuries.
Asunto(s)
Prueba de Esfuerzo , Carrera , Humanos , Carrera/fisiología , Masculino , Fenómenos Biomecánicos , Adulto , Femenino , Rango del Movimiento Articular/fisiología , Fatiga/fisiopatología , Fatiga Muscular/fisiologíaRESUMEN
Resumo Além das determinantes fisiológicas, o desempenho em maratonas é influenciado por características antropométricas, de treinamento e de experiência dos atletas. O objetivo do estudo foi investigar a associação desses fatores com o desempenho de maratonistas brasileiros. Um questionário foi aplicado nos dois dias anteriores à Maratona Internacional de Porto Alegre. Dentre os achados, os atletas de menor índice de massa corporal foram mais rápidos e o desempenho em provas de 5 e 21 km apresentou correlações altas com o desempenho (r = 0,76 e r = 0,81, p < 0,01). Isso sugere que corredores mais rápidos na maratona são mais rápidos em provas de distâncias menores. Além disso, índices como experiência anterior e distância dos treinos longos não foram bons preditores do desempenho para maratona.
Abstract Not only physiological variables, but anthropometric, training and experience characteristics influence marathon performance. The aim of this study was to investigate the correlation of those factors on Brazilian marathoners performance. A questionnaire was applied in the two days prior to the International Porto Alegre Marathon. Mainly, athletes with lower body mass index were faster on the race, and performance at 5 km and 21 km have high correlations with marathon performance (r=0.76 and r=0.81, p<0.01), suggesting that the fastest runners in the marathon are faster over shorter distances. In addition, indices like previous experience and long session distances were not good performance predictors for marathoners.
Resumen Además de los determinantes fisiológicos, el rendimiento en maratones está influenciado por las características antropométricas, el entrenamiento y la experiencia de los atletas. El objetivo del estudio fue investigar la asociación de estos factores con el rendimiento de los corredores de maratón brasileños. Se aplicó un cuestionario en los dos días antes de la Maratón Internacional de Porto Alegre. Entre los hallazgos, los atletas con menor índice de masa corporal fueron más rápidos, y el rendimiento en las pruebas de 5 y 21 km están altamente correlacionados con el rendimiento (r = 0,76 yr = 0,81, p <0,01), lo que sugiere que los corredores más rápidos en la maratón son más rápidos en pruebas de distancias más cortas. Además, los índices tales como la experiencia previa y la distancia de entrenamientos largos no fueron buenos indicadores de rendimiento para la maratón.
RESUMEN
PURPOSE: Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet) and an improvement in running performance is feasible with strength training of the postural and trunk muscles. METHODS: Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16) or the Pilates group (PG, n = 16). RESULTS: Confirming our hypothesis, a significant improvement (p<0.05) was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min) compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min). Similarly, the PG (4.33±0.07 J.kg-1.m-1) had better responses than the CG (4.71±0.11 J.kg-1.m-1) during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG. CONCLUSIONS: Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners.