scholarly journals Monocarboxylate transporters, blood lactate removal after supramaximal exercise, and fatigue indexes in humans

2005 ◽  
Vol 98 (3) ◽  
pp. 804-809 ◽  
Author(s):  
C. Thomas ◽  
S. Perrey ◽  
K. Lambert ◽  
G. Hugon ◽  
D. Mornet ◽  
...  

The present study investigated whether muscular monocarboxylate transporter (MCT) 1 and 4 contents are related to the blood lactate removal after supramaximal exercise, fatigue indexes measured during different supramaximal exercises, and muscle oxidative parameters in 15 humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (γ2), which denoted the blood lactate removal ability. Fatigue indexes were calculated during 1-min all-out (FIAO) and repeated 10-s (FISprint) cycling sprints. Biopsies were taken from the vastus lateralis muscle. MCT1 and MCT4 contents were quantified by Western blots, and maximal muscle oxidative capacity ( Vmax) was evaluated with pyruvate + malate and glutamate + malate as substrates. The results showed that the blood lactate removal ability (i.e., γ2) after a 1-min all-out test was significantly related to MCT1 content ( r = 0.70, P < 0.01) but not to MCT4 ( r = 0.50, P > 0.05). However, greater MCT1 and MCT4 contents were negatively related with a reduction of blood lactate concentration at the end of 1-min all-out exercise ( r = −0.56, and r = −0.61, P < 0.05, respectively). Among skeletal muscle oxidative indexes, we only found a relationship between MCT1 and glutamate + malate Vmax ( r = 0.63, P < 0.05). Furthermore, MCT1 content, but not MCT4, was inversely related to FIAO ( r = −0.54, P < 0.05) and FISprint ( r = −0.58, P < 0.05). We concluded that skeletal muscle MCT1 expression was associated with the velocity constant of net blood lactate removal after a 1-min all-out test and with the fatigue indexes. It is proposed that MCT1 expression may be important for blood lactate removal after supramaximal exercise based on the existence of lactate shuttles and, in turn, in favor of a better tolerance to muscle fatigue.

2004 ◽  
Vol 97 (6) ◽  
pp. 2132-2138 ◽  
Author(s):  
C. Thomas ◽  
P. Sirvent ◽  
S. Perrey ◽  
E. Raynaud ◽  
J. Mercier

The present study investigated whether blood lactate removal after supramaximal exercise and fatigue indexes measured during continuous and intermittent supramaximal exercises are related to the maximal muscle oxidative capacity in humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (γ2), which denoted the blood lactate removal ability. Fatigue indexes were calculated during all-out (FIAO) and repeated 10-s cycling sprints (FISprint). Biopsies were taken from the vastus lateralis muscle, and maximal ADP-stimulated mitochondrial respiration ( Vmax) was evaluated in an oxygraph cell on saponin-permeabilized muscle fibers with pyruvate + malate and glutamate + malate as substrates. Significant relationships were found between γ2 and pyruvate + malate Vmax ( r = 0.60, P < 0.05), γ2 and glutamate + malate Vmax ( r = 0.66, P < 0.01), and γ2 and citrate synthase activity ( r = 0.76, P < 0.01). In addition, γ2, glutamate + malate Vmax, and pyruvate + malate Vmax were related to FIAO (γ2 − FIAO: r = 0.85; P < 0.01; glutamate + malate Vmax − FIAO: r = 0.70, P < 0.01; and pyruvate + malate Vmax − FIAO: r = 0.63, P < 0.01) and FISprint (γ2 − FISprint: r = 0.74, P < 0.01; glutamate + malate Vmax − FISprint: r = 0.64, P < 0.01; and pyruvate + malate Vmax − FISprint: r = 0.46, P < 0.01). In conclusion, these results suggested that the maximal muscle oxidative capacity was related to blood lactate removal ability after a 1-min all-out test. Moreover, maximal muscle oxidative capacity and blood lactate removal ability were associated with the delay in the fatigue observed during continuous and intermittent supramaximal exercises in well-trained subjects.


1990 ◽  
Vol 68 (3) ◽  
pp. 905-911 ◽  
Author(s):  
S. Oyono-Enguelle ◽  
J. Marbach ◽  
A. Heitz ◽  
C. Ott ◽  
M. Gartner ◽  
...  

Venous lactate concentrations of nine athletes were recorded every 5 s before, during, and after graded exercise beginning at a work rate of 0 W with an increase of 50 W every 4th min. The continuous model proposed by Hughson et al. (J. Appl. Physiol. 62: 1975-1981, 1987) was well fitted with the individual blood lactate concentration vs. work rate curves obtained during exercise. Time courses of lactate concentrations during recovery were accurately described by a sum of two exponential functions. Significant direct linear relationships were found between the velocity constant (gamma 2 nu) of the slowly decreasing exponential term of the recovery curves and the times into the exercise when a lactate concentration of 2.5 mmol/l was reached. There was a significant inverse correlation between gamma 2 nu and the rate of lactate increase during the last step of the exercise. In terms of the functional meaning given to gamma 2 nu, these relationships indicate that the shift to higher work rates of the increase of the blood lactate concentration during graded exercise in fit or trained athletes, when compared with less fit or untrained ones, is associated with a higher ability to remove lactate during the recovery. The results suggest that the lactate removal ability plays an important role in the evolution pattern of blood lactate concentrations during graded exercise.


Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4729 ◽  
Author(s):  
Taha Khan ◽  
Lina E. Lundgren ◽  
Eric Järpe ◽  
M. Charlotte Olsson ◽  
Pelle Viberg

Blood lactate accumulation is a crucial fatigue indicator during sports training. Previous studies have predicted cycling fatigue using surface-electromyography (sEMG) to non-invasively estimate lactate concentration in blood. This study used sEMG to predict muscle fatigue while running and proposes a novel method for the automatic classification of running fatigue based on sEMG. Data were acquired from 12 runners during an incremental treadmill running-test using sEMG sensors placed on the vastus-lateralis, vastus-medialis, biceps-femoris, semitendinosus, and gastrocnemius muscles of the right and left legs. Blood lactate samples of each runner were collected every two minutes during the test. A change-point segmentation algorithm labeled each sample with a class of fatigue level as (1) aerobic, (2) anaerobic, or (3) recovery. Three separate random forest models were trained to classify fatigue using 36 frequency, 51 time-domain, and 36 time-event sEMG features. The models were optimized using a forward sequential feature elimination algorithm. Results showed that the random forest trained using distributive power frequency of the sEMG signal of the vastus-lateralis muscle alone could classify fatigue with high accuracy. Importantly for this feature, group-mean ranks were significantly different (p < 0.01) between fatigue classes. Findings support using this model for monitoring fatigue levels during running.


1993 ◽  
Vol 74 (1) ◽  
pp. 435-443 ◽  
Author(s):  
P. G. Catcheside ◽  
G. C. Scroop

Arterial blood lactate was elevated by supine leg exercise (20 min at approximately 65% maximal oxygen uptake) in five untrained male subjects, and the contribution to blood lactate removal from passive uptake vs. metabolic disposal was compared in resting and lightly exercising (15% maximal voluntary contraction static handgrip) forearm skeletal muscle. An integrated form of the Fick equation was used to predict venous lactate levels resulting solely from passive equilibration of lactate between incoming arterial blood and the forearm muscles. In the resting forearm, predicted and measured venous lactate levels were closely correlated during the exercise period (r = 0.995, P < 0.001), indicating that lactate removal could be accounted for in terms of passive uptake alone. In the lightly exercising forearm, measured venous lactate levels were higher than both the arterial and predicted venous levels, indicating net lactate production. It was concluded that most of the blood lactate generated by moderate-intensity supine leg exercise is taken up passively and not metabolized by resting skeletal muscle and that the rate of lactate disposal is unlikely to be enhanced in lightly exercising muscle.


1999 ◽  
Vol 87 (5) ◽  
pp. 1713-1718 ◽  
Author(s):  
George A. Brooks ◽  
Marcia A. Brown ◽  
C. E. Butz ◽  
James P. Sicurello ◽  
Hervé Dubouchaud

To evaluate the potential role of monocarboxylate transporter-1 (MCT1) in tissue lactate oxidation, isolated rat subsarcolemmal and interfibrillar cardiac and skeletal muscle mitochondria were probed with an antibody to MCT1. Western blots indicated presence of MCT1 in sarcolemmal membranes and in subsarcolemmal and interfibrillar mitochondria. Minimal cross-contamination of mitochondria by cell membrane fragments was verified by probing for the sarcolemmal protein GLUT-1. In agreement, immunolabeling and electron microscopy showed mitochondrial MCT1 in situ. Along with lactic dehydrogenase, the presence of MCT1 in striated muscle mitochondria permits mitochondrial lactate oxidation and facilitates function of the “intracellular lactate shuttle.”


2011 ◽  
Vol 6 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Jason D. Vescovi ◽  
Olesya Falenchuk ◽  
Greg D. Wells

Purpose:Blood lactate concentration, [BLa], after swimming events might be influenced by demographic features and characteristics of the swim race, whereas active recovery enhances blood lactate removal. Our aims were to (1) examine how sex, age, race distance, and swim stroke influenced [BLa] after competitive swimming events and (2) develop a practical model based on recovery swim distance to optimize blood lactate removal.Methods:We retrospectively analyzed postrace [BLa] from 100 swimmers who competed in the finals at the Canadian Swim Championships. [BLa] was also assessed repeatedly during the active recovery. Generalized estimating equations were used to evaluate the relationship between postrace [BLa] with independent variables.Results:Postrace [BLa] was highest following 100–200 m events and lowest after 50 and 1500 m races. A sex effect for postrace [BLa] was observed only for freestyle events. There was a negligible effect of age on postrace [BLa]. A model was developed to estimate an expected change in [BLa] during active recovery (male = 0; female = 1): [BLa] change after active recovery = –3.374 + (1.162 × sex) + (0.789 × postrace [BLa]) + (0.003 × active recovery distance).Conclusions:These findings indicate that swimmers competing at an elite standard display similar postrace [BLa] and that there is little effect of age on postrace [BLa] in competitive swimmers aged 14 to 29 y.


1980 ◽  
Vol 48 (4) ◽  
pp. 689-694 ◽  
Author(s):  
T. T. Gleeson

Gas exchange (VO2 and VCO2) and blood lactate concentration were measured in the lizard Amblyrhynchus cristatus at 25 and 35 degrees C during resting, running, and recovery after exhaustion (less than or equal to 180 min) to analyze the temperature dependency of metabolic recovery in this lizard. Amblyrhynchus exhausted twice as fast (4.2 vs. 8.8 min) at 25 degrees C than when running at the same speed at 35 degrees C. At both temperatures, VO2 and VCO2 increased rapidly during activity and declined toward resting levels during recovery in a manner similar to other vertebrates. Respiratory quotients (R, where R = VCO2/VO2) exceeded 2.0 after exhaustion at both temperatures. Extensive lactate production occurred during activity; blood lactate concentrations ranged from 1.0 to 1.7 mg lactate/ml blood after activity. Net lactate removal exhibited a temperature dependence. Blood lactate concentrations remained elevated hours after VO2 returned to normal. Endurance was reduced in lizards that had recovered aerobically but still possessed high lactate concentrations. The temporal separation of the excess oxygen consumption and lactate removal suggests that the concept of the lactacid oxygen debt is not applicable to this animal. The temperature dependence of total metabolic recovery suggests a benefit for Amblyrhynchus that select warm basking temperatures following strenuous activity.


2020 ◽  
Vol 41 (13) ◽  
pp. 936-943
Author(s):  
Hugo Maciejewski ◽  
Muriel Bourdin ◽  
Léonard Féasson ◽  
Hervé Dubouchaud ◽  
Laurent André Messonnier

AbstractThis study aimed to test if the non-oxidative energy supply (estimated by the accumulated oxygen deficit) is associated with an index of muscle lactate accumulation during exercise, muscle monocarboxylate transporter content and the lactate removal ability during recovery in well-trained rowers. Seventeen rowers completed a 3-min all-out exercise on rowing ergometer to estimate the accumulated oxygen deficit. Blood lactate samples were collected during the subsequent passive recovery to assess individual blood lactate curves, which were fitted to the bi-exponential time function: La(t)= [La](0)+A1·(1–e–γ 1 t)+A2·(1–e–γ 2 t), where the velocity constants γ1 and γ2 (min–1) denote the lactate exchange and removal abilities during recovery, respectively. The accumulated oxygen deficit was correlated with the net amount of lactate released from the previously active muscles (r =0.58, P<0.05), the monocarboxylate transporters MCT1 and MCT4 (r=0.63, P<0.05) and γ2 (r=0.55, P<0.05). γ2 and the lactate release rate at exercise completion were negatively correlated with citrate synthase activity. These findings suggest that the capacity to supply non-oxidative energy during supramaximal rowing exercise is associated with muscle lactate accumulation and transport, as well as lactate removal ability.


1991 ◽  
Vol 71 (2) ◽  
pp. 514-520 ◽  
Author(s):  
L. B. Gladden

The purpose of this study was to determine the changes in net lactate uptake (L) by skeletal muscle with a constant elevated blood lactate concentration during steady-level contractions of increasing intensity. The gastrocnemius-plantaris muscle group was isolated in situ in 11 anesthetized dogs. An infusion of lactate/lactic acid at a pH of 3.5–3.7 established a blood lactate concentration of approximately 9 mM while maintaining normal blood gas/pH status. L was measured during three consecutive 30-min periods during which the muscles 1) rested, 2) contracted at 1 Hz, and 3) contracted at 4 Hz. L was always positive, indicating net uptake throughout the lactate/lactic acid infusion. Steady-level O2 uptake averaged 10.9 +/- 2.2 ml.kg-1.min-1 (0.49 +/- 0.10 mmol.kg-1.min-1) at rest, 39.3 +/- 2.1 (1.75 +/- 0.09) at 1 Hz, and 127.8 +/- 9.2 (5.70 +/- 0.41) at 4 Hz. Steady-level L increased with the metabolic rate from 0.113 +/- 0.058 mmol.kg-1.min-1 at rest to 0.329 +/- 0.026 at 1 Hz and 0.715 +/- 0.108 at 4 Hz. The increase in L from rest to 1 Hz was accomplished mainly by an increase in arteriovenous lactate difference, whereas the increase from 1 to 4 Hz was entirely due to a large increase in blood flow. These results support the idea that skeletal muscle is not simply a producer of lactate but can be a significant consumer of lactate even during contractions with a large elevation in metabolic rate.


1980 ◽  
Vol 49 (6) ◽  
pp. 1057-1069 ◽  
Author(s):  
G. A. Brooks ◽  
G. A. Gaesser

To determine the extent of metabolite oxidation, rats were injected with [U-14C]lactate, -glucose, or -bicarbonate (n = 5, each) during rest or after continuous (CE) and intermittent (IE) exercises to exhaustion. Tissue analyses of resting rats, or rats killed following CE and IE and pulse injection with [14C]lactate or -glucose (n = 72, each), were used to determine the metabolic pathways of these two substrates. Oxygen consumption (VO2) declined rapidly for the first 15 min after exercise; thereafter, VO2 declined slowly and remained elevated above resting levels for 120 min. The slow phase of decline in VO2 during recovery did not coincide with lactate removal, which occurred within 15 min. Two-dimensional radiochromatograms produced from blood, kidney, liver, skeletal muscle, and heart indicated a rapid incorporation of 14C into several amino acid pools, including alanine, glutamine, glutamate, and aspartate. Four-hour postexercise recoveries (means of CE and IE) of injected [14C]lactate were lactate (0.75%), glucose (0.52%), protein (8.57%), glycogen (18.30%), CO2 (45.18%), and HCO3- (17.72%). Greater (P < 0.05) incorporation of 14C into protein and glycogen constituents after exercise, compared with rest, was demonstrated. Incorporation of [14C]lactate into glycogen represented a significant but only minor fraction of the metabolism of lactate after exhausting exercise. It is suggested that classical explanations of excess postexercise O2 consumption (i.e., "O2 debt") are too simplistic.


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