Produção de torque no ciclismo: análise da simetria na pedalada durante 40 km simulados

Abstract

The aim of this study was verify the torque production in cycling during 40 km, also verifying the relationships between symmetry of torque, dominant member and intensity of the exercise (%VO2max). A group of 5 mountain bike cross country cyclists (age 24.4 years old, height 1.81 m, body mass 73.48 kg, and VO2max 55.16 ml.kg-1.min-1) was submitted to two protocols with 48 h of maximal interval, being the first a test for determination of the maximum oxygen uptake (VO2max) in ramp protocol (start at 100 W with increment of 25 W.min-1), using the cyclergometry SRM Training System and gas analyzer Aerosport TEEM 100. The second protocol consisted in the execution of a 40 km simulated test in the cyclergometry SRM Training System, where the oxygen uptake and propulsive torque produced by lower limbs was analyzed. The torque was analyzed during 10 s, to every 5 minutes during the 40 km course, being assumed the percentile differences equal or superiors at 10% among the peaks of the right and left member as asymmetry. The average time to the 40 km was 62 min 35 s, and the average intensity was 66.33%VO2max. For the torque, the results show that each cyclist presented a differentiated answer to the protocol. The average torque during the 40 km presented a relationship with the torque peak in the 40 km (r = 0.87). With relationship to the symmetry in the propulsive torque, the results show that the cyclists have asymmetry, however, this situation varied during the 40 km and among the subjects, not presenting a pattern defined. The analysis of the propulsive torque in relation to the dominant member (kick leg) it showed that the same presented a relationship with the torque peak, e. g., the torque peak was produced by the dominant member in the majority cases. The intensity of the exercise doesn’t be a factor determinant for the asymmetry, because different answers were observed the study group. In summary, the studied cyclists develop torque in an asymmetric way in different stages along a course of 40 km, that’s asymmetry is related to the dominant member and nor the intensity of the exercise. For a best understanding of the torque production during pedaling, suggests the use of instrumented pedals and the accomplishment of individualized evaluations because the differences observed among the subjects.