THE CAFFEINE INGESTION INCREASES TIME TO NEUROMUSCULAR FATIGUE AND PERFORMANCE DURING SUPRAMAXIMAL CYCLING EXERCISE

ALTIMARI, L. R.; FONTES, E. B.; OKANO, A. H.; TRIANA, R. O.; CHACON-MIKAHIL, M. P. T.; MORAES, A. C. The caffeine ingestion increases time to neuromuscular fatigue and performance during supramaximal cycling exercise. Brazilian Journal of Biomotricity, v. 2, n. 3, p. 195-203, 2008.The purpose of this study was to investigate the effect of the caffeine ingestion (CAF) on the neuromuscular fatigue (NMF) and performance during supramaximal cycling exercise. Nine male cyclists (27.2 ± 3.9 yr; 73.7 ± 12.3 kg and 174.2 ± 6.1 cm), trained, were subjected to two tests of constant load (Tcons) separated by 72 h intervals in intensity of 110% wmax until exhaustion conducted randomly in CAF and PL conditions. CAF (6 mg.kg-1) or PL (maltodextrin) were administred in a double-blind procedure 60 min before the start of Tcons. During the Tcons were obtained the time of exhaustion (TE) and time of onset of neuromuscular fatigue (TONMF) (s) through electromyographic activity (EMG) of the vastus lateralis (VL), vastus medialis (VM) e rectus femoris (RF) muscles. Normality of the data distribution was confirmed using the Shapiro-Wilk test, and this was followed by Student t-tests with level of significance set at P<0.05. The TE was 15% higher on condition CAF compared to PL (132.3 ± 8.4 and 116.7 ± 7.6 s, P<0.05, respectively). Significant difference was found between the TONMF of VL, VM and RF muscles when compared to CAF and PL conditions (P<0.05). According to these results, it can be concluded that the ingestion of 6 mg.kg-1 of caffeine increases time to neuromuscular fatigue and performance during supramaximal in cycling exercise.