Correlation between blood lactate curve and absolute muscle power on lower limbsin athletes with predominance of slow twitch (S.T.) and fast twitch (F.T.) fiber

Abstract

Knowing the metabolic and functional differences between muscle fi ber types is important not only in the process of the athlete’s physical evaluation, but also for a better elaboration of training programs. For this study, 16 elite male athletes (22.3±2.94 years old) have been examined, divided in two groups of eight athletes each according to the estimated composition of muscle fi bers (Face Validity): Group 1 (sprint runners – Type II fi ber – FT) and Group 2 (marathon runners – Type I fi ber – ST). After an evaluation of body composition, the athletes underwent a test of alactic anaerobic power and, to confi rm the muscle metabolic profi le, a running test with intervals was done, using three stimuli of increasing intensity and with decreasing distances, where, at the end of the third minute of each phase, a blood sample was extracted in order to determine the blood lactate concentration, using the method of enzymatic determination and refl ectance photometry (Accusport). The statistics test used was Pearson’s correlation analysis, combined with Student’s t-test. The conclusion is that all correlations found were signifi cant (p > 0.05), regardless of the fi ber type and that there is a direct proportionality relation (r > 0) between the concentration levels of blood lactate and AAPU. Putting the variables together, we evidence that the muscle fi ber type is a determinant factor in muscle power indexes and is strongly responsible for the higher blood lactate concentration levels. COUTINHO, M.H.P. Correlation between blood lactate curve and absolute muscle power on lower limbsin athletes with predominance of slow twitch (S.T.) and fast twitch (F.T.) fi ber. Fitness & Performance Journal, v.3, n.1, p.41-46, 2004. Rua Aberema, 322/102 – Jardim Guanabara – Rio de Janeiro – CEP 21940-190