Predição da máxima fase estável de lactato no ciclismo a partir do desempenho em teste de 5km

Abstract

Stationary cycling tests were used to analyze the validity of methods for estimating the Maximal Lactate Steady State (MLSS) and the velocity and heart rate (HR) that are sustainable during a 40-km time trial. Methods: 11 cyclists (23.9±4.1 years; 178±6.8 cm tall; 68.8±5.4 kg) performed the following tests on a cyclosimulator, using their own bicycles: 1) Determination of the mean velocity and HR achieved during a 5-km (5kmVel and HR5km) and a 40-km time trial (40kmVel and HR40km). 2) 2-3 endurance tests to determine MLSSV with blood lactate ([lac]) measurements. The relationship between MLSSV and 5kmVel in data from Harnish et al. (2001) was also used to calculate predicted MLSSV (km·h-1): [MLSSVp = 0.8809 x 5kmVel + 1.6365]. The HR corresponding to MLSSV (MLSSHR) was estimated by taking 88% of HR5km (maximal- HR) (Swensen et al. 1999). Results: The 5kmVel, 40kmVel, MLSSV and MLSSVp were 50.07±2.03, 45.57±1.97, 45.64±2.0 and 45.77±1.77km·h-1 respectively. No differences were found between 40kmVel, MLSSV and MLSSVp. Neither did [lac] or HR corresponding to MLSSV/40kmVel exhibit differences (4.5±0.6/4.2±0.3mM and 175.1±3.0/176.8±3.1 bpm). The MLSSV was 90.9±0.5% of 5kmVel and MLSSHR was 93.6±0.5% of HR5km. Conclusion: The equation proposed is valid for estimating both MLSSV and 40kmVel on a stationary cyclosimulator.