A study of lactate metabolism without tracer during passive and active postexercise recovery in humans

Abstract

Tracers have been used extensively to study lactate metabolism in humans during rest and exercise. Nevertheless, quantification of in vivo lactate kinetics as measured by lactate tracers remains controversial and new data are necessary to clarify the issue. The present study has developed a simple kinetic model which does not require labelled molecules and which yields proportional and quantitative information on lactate metabolism in humans during postexercise recovery performed at different levels of intensity. Five subjects took part in six experiments each of which began with the same strenuous exercise (StrEx; 1 min, 385 W, 110 rpm). The StrEx of each session was followed by a different intensity of recovery: passive recovery (PR) and active recoveries (AR) with power outputs of 60, 90, 120, 150 and 180 W, respectively. Blood lactate concentration was measured prior to and immediately after StrEX and regularly during the 1st h of recovery. Oxygen uptake (VO2) was measured every ... Document type : Article de périodique (Journal article) Référence bibliographiqueFrancaux, Marc ; Jacqmin, P. ; de Welle, J M ; Sturbois, Xavier. A study of lactate metabolism without tracer during passive and active postexercise recovery in

Active and Passive Recovery and Acid-Base Kinetics Following Multiple Bouts of Intense Exercise to Exhaustion

“…The only difference between the protocols was the recovery activity. Recovery samples were drawn with the subject cycling at 60 RPM and 20% of their MWO for 12 min (8,25).…”

Differences in Lactate Exchange and Removal Abilities in Athletes Specialised in Different Track Running Events (100 to 1500 m)

“…A bicompartmental model of the lactate distribution space [12] and a one open compartment model [9] have been proposed to interpret blood lactate recovery curves and investigate lactate movements during and after muscular exercise in humans. In the model of Freund and Zouloumian [12], the velocity constants g 1 and g 2 (min -1 ) of the bi-exponential time function fitted to the arterial [30] lactate recovery curves obtained after muscular exercise, have been shown to supply qualitative and quantitative information on both the ability to exchange lactate between the previously active muscles and blood (g 1 ), and the body's overall ability to remove lactate (g 2 ) during recovery.…”

“…A major interest of this non-invasive methodology is that it allows to estimate in vivo, and in unsteadystate conditions, two dynamic parameters of lactate kinetics. If the model of Francaux et al [9] allows an estimation of parameters providing equivalent information about g 1 and g 1 (k a and k e , respectively), the strong analogies underlined by previous reports [11,19,29] between the values of g 1 and g 2 and the lactate kinetics parameters obtained by tracer methods or in vitro have finally oriented our choice of model on that proposed by Freund and Zouloumian [12]. This modelling approach has never been applied to athletic performance involving high-energy supply via lactate metabolism.…”

Effects of Prior Exercise on Force-Velocity Test Performance and Quadriceps EMG

“…This result is comparable to that of Billat [4] and Robergs [24] who reported that blood lactate concentration remained unchanged despite a 10 -15-min recovery separating the intermittent prior exercise from the subsequent intense exercise. This can most likely be explained by the passive nature of recovery [10].…”