Blood lactate during recovery from intense exercise: Impact of inspiratory loading

• Autor(a) principal: Chiappa, Gaspar R.
• Data de Publicação: 2008
• Outros Autores: Roseguini, Bruno T., Alves, Cristiano N., Ferlin, Elton L., Neder, Jose Alberto [UNIFESP], Ribeiro, Jorge P.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1249/mss.0b013e3181591de1; http://repositorio.unifesp.br/handle/11600/30244
• topic: lactate metabolism; excess postexercise oxygen consumption; inspiratory muscles; work of breathing

Purpose: It has long been suggested that inspiratory muscle activity may impact blood lactate levels ([Lac(-)](B)) during the recovery from dynamic exercise. in this study, we tested the hypothesis that inspiratory muscle activation during recovery from intense exercise would contribute to La- clearance, thus leading to reduced [Lac(-)](B.) Methods: Twelve healthy men underwent two maximal, incremental exercise tests on different days. During a 20-min inactive recovery period, they breathed freely or against a fixed inspiratory resistance of 15 cm H2O. During recovery, pulmonary gas exchange was continuously monitored, and serial samples of arterialized venous blood were obtained for [Lac(-)](B), pH, PCO2, and HCO3 (-), Results: Subjects presented similar ventilatory and gas-exchange responses at peak exercise during both experimental conditions. [Lac(-)](B) during recovery was reduced with inspiratory resistance (7.7 +/- 1 vs 10.4 +/- 1, 7.8 2 vs 10.3 +/- 2, and 7.3 +/- 1 vs 9.7 +/- 2 mM at 5, 7, and 9 min of recovery, respectively; P < 0.05), but no differences were found for blood acid-base status. Inspiratory resistance was associated with increased metabolic demand (VO2 and VCO2) but improved ventilatory efficiency, with lower V-E/[VCO2] and increased alveolar ventilation. Conclusion: These data are consistent with the notion that inspiratory muscles may be net consumers of lactate during recovery from intense exercise.