The influence of the allometric scale on the relationship between running economy and biomechanical variables in distance runners

Studies have demonstrated the need for the use of parameters that diminish the effect of body mass, for intra and inter group comparison, in individuals with different masses in order to provide a different analysis on the behaviour of the relation between running economy (RE) and biomechanical variables (BVs). The allometric scale is represented by a regression equation that indicates the behaviour of a physiological variable in relation to the variable mass (RE=a.xb), where x is body mass in (kg) and the dimensionless coefficient a is characteristic of the species analysed, and the dimensionless exponent b determines the percentage of mass to be associated with the physiological variable. The influence of the allometric scale (b=-1; -0.75; -0.73; -0.67) on the relationship between RE and BVs - stride length (SL), relative stride length (RSL), stride rate (SR), stride time (ST), support time (SUPT) and balance time (BALT) - at 12 km.h-1, was analysed in nine elite runners. Factorial analysis and Pearson's Correlation Coefficient test (r) with P<0.05 were used. A decrease in the explanation power of the RE was observed, with the use of the allometric exponent, due to the BVs, as well as a reduction of the correlation coefficients between SL versus RE, ST versus RE and SR versus RE. The BALT presented a higher correlation where b=-0.75. The RSL and SUPT presented non-significant correlations. The variables SL, ST, SR and BALT were the most effective predictors of the RE, Where: b=-1, the allometric scale was most efficient to predict the running performance

Corrida em piscina funda: limites e possibilidades para o alto desempenho Velocidad en piscina de profundidad: límites y posibilidades para un alto desempeño Deep water running: limits and possibilities for high performance

O objetivo deste estudo foi analisar os limites e possibilidades da utilização da corrida em piscina funda no treinamento de corredores de rendimento. Além disso, são discutidas as respostas agudas submáximas, máximas e crônicas, do ponto de vista fisiológico e biomecânico entre a corrida em terra e em piscina funda. As respostas máximas de freqüência cardíaca e consumo de oxigênio são menores no exercício aquático do que na corrida terrestre. Dados experimentais sugerem o uso do treinamento de corrida em piscina funda para corredores de rendimento; contudo, essas evidências são limitadas para treinamentos de até 10 semanas.<br>El objetivo de este estudio ha sido el de analizar los límites y posibilidades de la utilización de carreras de velocidad en piscina de profundidad durante el entrenamiento de velocista de rendimiento. Además de esto, son discutidas las respuestas agudas submáximas, máximas y crónicas, bajo el punto de vista fisiológico y biomecánico entre la carrera en tierra y en piscina profunda. Las respuestas máximas de frecuencia cardíaca y consumo de oxígeno son menores en el ejercicio acuático que en la de tierra. Datos experimentales sugieren el uso de entrenamiento de carrera en piscina profunda para velocistas de rendimiento, sin embargo estas evidencias son limitadas a entrenamientos de hasta 10 semanas.<br>The purpose of this study was to analyze the limits and possibilities of deep water running on training of performance runners. Besides, it has been discussed the submaximal acute, maximal acute and chronical responses, following physiological and biomechanical aspects between running on land and deep water running. Heart rate and oxygen uptake's maximal responses are lower in aquatic exercise than in running on land. Experimental evidences suggest the deep water running training for performance athletes, but these studies are limited in training program until ten weeks