Acute anemia increases lactate production and decreases clearance during exercise

We evaluated whether elevated blood lactate concentration during exercise in anemia is the result of elevated production or reduced clearance. Female Sprague-Dawley rats were made acutely anemic by exchange transfusion of plasma for whole blood. Hemoglobin and hematocrit were reduced 33%, to 8.6 +/- 0.4 mg/dl and 26.5 +/- 1.1%, respectively. Blood lactate kinetics were studied by primed continuous infusion of [U-14C]lactate. Blood flow distribution during rest and exercise was determined from injection of 153Gd- and 113Sn-labeled microspheres. Resting blood glucose (5.1 +/- 0.2 mM) and lactate (1.9 +/- 0.02 mM) concentrations were not different in anemic animals. However, during exercise blood glucose was lower in anemic animals (4.0 +/- 0.2 vs. 4.6 +/- 0.1 mM) and lactate was higher (6.1 +/- 0.4 vs. 2.3 +/- 0.5 mM). Blood lactate disposal rates (turnover measured with recyclable tracer, Ri) were not different at rest and averaged 136 +/- 5.8 mumol.kg-1.min-1. Ri was significantly elevated in both control (260.9 +/- 7.1 mumol.kg-1.min-1) and anemic animals (372.6 +/- 8.6) during exercise. Metabolic clearance rate (MCR = Ri/[lactate]) did not differ during rest (151 +/- 8.2 ml.kg-1.min-1); MCR was reduced more by exercise in anemic animals (64.3 +/- 3.8) than in controls (129.2 +/- 4.1). Plasma catecholamine levels were not different in resting rats, with pooled mean values of 0.45 +/- 0.1 and 0.48 +/- 0.1 ng/ml for epinephrine (E) and norepinephrine (NE), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Download Full-text

Glucose kinetics in gluconeogenesis-inhibited rats during rest and exercise

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1990.258.1.e203 ◽

1990 ◽

Vol 258 (1) ◽

pp. E203-E211 ◽

Cited By ~ 6

Author(s):

L. P. Turcotte ◽

A. S. Rovner ◽

R. R. Roark ◽

G. A. Brooks

Keyword(s):

Blood Glucose ◽

Blood Lactate ◽

Blood Glucose Concentration ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Sprague Dawley ◽

Glucose Kinetics ◽

Sprague Dawley Rats ◽

Blood Glucose Homeostasis ◽

Glucose Recycling

To evaluate the role played by gluconeogenesis in blood glucose homeostasis, female Sprague-Dawley rats were injected with mercaptopicolinic acid (MPA), a gluconeogenic inhibitor. Glucose kinetics were assessed by primed, continuous infusion of [U-14C]- and [6(-3)H]glucose via an indwelling jugular catheter at rest and during submaximal exercise at 13.4 m/min on level grade. Blood samples were taken from carotid catheters and analyzed for glucose and lactate concentrations and specific activities. Tissue glycogen samples were obtained from rats after exercise as well as from unexercised animals. When compared with the sham-injected animals, MPA-treated animals had 22% lower (5.92 +/- 0.36 vs. 7.62 +/- 0.21 mM) and 44% higher (1.90 +/- 0.11 vs. 1.32 +/- 0.09 mM) resting arterial glucose and lactate concentrations, respectively. Resting glucose appearance (Ra) rates were 20% lower in the MPA-treated animals (57.2 +/- 7.5 mumol.kg-1.min-1) than in the sham-injected animals (71.1 +/- 12.1 mumol.kg-1.min-1). During exercise, Ra increased to 174.7 +/- 32.8 mumol.kg-1.min-1 in sham-injected animals. In the MPA-treated animals, there was a 35% increase during the first 15 min of exercise, followed by a decrease to the resting values. MPA-treated animals had no measurable glucose recycling at rest or during exercise. Exercise decreased blood glucose concentration (35%) and increased blood lactate concentration (160%) in the MPA-treated animals. Exercising sham-injected animals had increased blood glucose (9.8%) but no change in blood lactate concentration. Moderate depletions in liver and skeletal muscle glycogen contents were observed after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Download Full-text

Increased clearance of lactate after short-term training in men

Journal of Applied Physiology ◽

10.1152/jappl.1995.79.6.1862 ◽

1995 ◽

Vol 79 (6) ◽

pp. 1862-1869 ◽

Cited By ~ 30

Author(s):

S. M. Phillips ◽

H. J. Green ◽

M. A. Tarnopolsky ◽

S. M. Grant

Keyword(s):

Blood Lactate ◽

Clearance Rate ◽

Maximal Oxygen Consumption ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Constant Infusion ◽

Metabolic Clearance ◽

Metabolic Clearance Rate ◽

Short Term ◽

Mitochondrial Potential

A short-term training model previously shown to result in a tighter metabolic control in working muscle in the absence of an increase in mitochondrial potential was used to examine changes in lactate turnover. Lactate flux was studied before and after 10 days of cycle training [2 h/day at 59% maximal oxygen consumption (VO2max)] in untrained men [VO2max = 45.5 +/- 2.4 (SE) ml.kg-1.min-1). A primed constant infusion of L-[1–13C]lactate was used to examine lactate kinetics during a prolonged exercise protocol (90 min at 59% VO2max). Rate of appearance of lactate increased with exercise (P < 0.01), both pretraining (rest = 30.3 +/- 4.9 ml.kg-1.min-1, exercise = 115 +/- 14 ml.kg-1.min-1) and posttraining (rest = 28.4 +/- 4.7 ml.kg-1.min-1, exercise = 112 +/- 13 ml.kg-1.min-1). Despite a lower blood lactate concentration (P < 0.05) during exercise after training, there was no difference in the rate of appearance of lactate. Training increased (P < 0.05) the metabolic clearance rate of lactate during exercise from 36.8 +/- 4.8 to 51.4 +/- 6.8 ml.kg-1.min-1. These findings indicate that at least part of the lower exercising blood lactate observed after training is due to an increase in metabolic clearance rate. In addition, the lower intramuscular lactate levels suggest a decreased recruitment of glycolysis particularly early in exercise.

Download Full-text

Metabolic recovery from exhaustive activity by a large lizard

Journal of Applied Physiology ◽

10.1152/jappl.1980.48.4.689 ◽

1980 ◽

Vol 48 (4) ◽

pp. 689-694 ◽

Cited By ~ 21

Author(s):

T. T. Gleeson

Keyword(s):

Temperature Dependence ◽

Blood Lactate ◽

Lactate Concentration ◽

Lactate Production ◽

Blood Lactate Concentration ◽

Excess Oxygen ◽

Temporal Separation ◽

Metabolic Recovery ◽

Strenuous Activity ◽

Lactate Removal

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.

Download Full-text

Effect of endurance training on activators of glycolysis in muscle during exercise

Journal of Applied Physiology ◽

10.1152/jappl.1994.76.2.846 ◽

1994 ◽

Vol 76 (2) ◽

pp. 846-852 ◽

Cited By ~ 12

Author(s):

C. Duan ◽

W. W. Winder

Keyword(s):

Endurance Training ◽

Blood Lactate ◽

Lactate Concentration ◽

Lactate Production ◽

Blood Lactate Concentration ◽

Quadriceps Muscle ◽

Muscle Lactate ◽

Cyclic Monophosphate ◽

Lactate Levels ◽

Exercise Induced

Endurance training attenuates exercise-induced increases in blood lactate at the same submaximal work rate. Three intramuscular compounds that influence muscle lactate production were measured in fasted non-trained (NT) and endurance-trained (T) rats. The T rats were subjected to a progressive endurance-training program. At the end of the program (11 wk), they were running 2 h/day at 31 m/min up a 15% grade 5 days/wk. NT and T rats were fasted for 24 h and then anesthetized (pentobarbital, iv) at rest or after running for 30 min at 21 m/min (15% grade). Blood lactate levels were significantly lower in the T rats than in the NT rats after 30 min of running (2.3 +/- 0.2 vs. 3.9 +/- 0.2 mM). The lower blood lactate concentration was accompanied by lower plasma epinephrine (2.8 +/- 0.4 vs. 6.0 +/- 0.8 nM), adenosine 3′, 3′,5′-cyclic monophosphate (0.36 +/- 0.02 vs. 0.50 +/- 0.03 pmol/mg), mg), glucose 1,6-diphosphate (26 +/- 2 vs. 40 +/- 5 pmol/mg), and fructose 2,6-diphosphate (3.2 +/- 0.2 vs. 4.3 +/- 0.3 pmol/mg) in white quadriceps muscle in T than in NT rats. Red quadriceps muscle glucose 1,6-diphosphate and adenosine 3′,5′-cyclic monophosphate were also lower in T than in NT rats. These adaptations may be responsible in part for the lower exercise-induced blood lactate in fasted rats as a consequence of endurance training.

Download Full-text

The Effect of Hyperventilation on the Lactacidaemia of Muscular Exercise

Clinical Science ◽

10.1042/cs0380269 ◽

1970 ◽

Vol 38 (2) ◽

pp. 269-276 ◽

Cited By ~ 10

Author(s):

R. H. T. Edwards ◽

Marie Clode

Keyword(s):

Blood Lactate ◽

Control Period ◽

Control Level ◽

Lactate Concentration ◽

Lactate Production ◽

Blood Lactate Concentration ◽

Respiratory Muscles ◽

Cycle Ergometer ◽

Exercise Tests ◽

End Tidal

1. Six men exercised at 600 kp m/min on a cycle ergometer. After a control period they hyperventilated at about twice the control level of ventilation. Capillary blood samples were taken for lactate estimations at the end of both 6 min periods. 2. Hyperventilation resulting in a fall in end-tidal Pco2 of 12·0 mmHg was associated with rise in blood lactate concentration of 1·07 mm/l. 3. It is concluded that the increase in blood lactate concentration attributable to hyperventilation is comparatively small in exercise tests involving short periods of moderately severe exertion. 4. In an additional subject exercising similarly, hyperventilation without a fall in Pco2 (‘normocapnic’ hyperventilation) was achieved by adding 3·8% CO2 to the inspired air. Subsequent hyperventilation while breathing air resulted in a fall in end-tidal Pco2 of 19·5 mmHg (‘hypocapnic’ hyperventilation) and a rise in blood lactate concentration of 1·21 mm/l. Parallel changes in pyruvate concentration occurred suggesting that lactate production had increased. Neither the origin nor the mechanism of this increase could be ascertained; however, it appeared unlikely to be due to increased anaerobic metabolism of the respiratory muscles as normocapnic hyperventilation was associated with virtually no change in blood lactate and pyruvate concentrations.

Download Full-text

Estimating energy expenditure for brief bouts of exercise with acute recovery

Applied Physiology Nutrition and Metabolism ◽

10.1139/h05-013 ◽

2006 ◽

Vol 31 (2) ◽

pp. 144-149 ◽

Cited By ~ 14

Author(s):

Christopher B Scott

Keyword(s):

Energy Expenditure ◽

Total Energy ◽

Blood Lactate ◽

Lactate Concentration ◽

Lactate Production ◽

Blood Lactate Concentration ◽

Total Energy Expenditure ◽

Post Exercise ◽

Anaerobic Energy ◽

Substrate Level

Four indirect estimations of energy expenditure were examined, (i) O2 debt, (ii) O2 deficit, (iii) blood lactate concentration, and (iv) excess CO2 production during and after 6 exercise durations (2, 4, 10, 15, 30, and 75 s) performed at 3 different intensities (50%, 100%, and 200% of VO2 max). Analysis of variance (ANOVA) was used to determine if significant differences existed among these 4 estimations of anaerobic energy expenditure and among 4 estimations of total energy expenditure (that included exercise O2 uptake and excess post-exercise oxygen consumption, or EPOC, measurements). The data indicate that estimations of anaerobic energy expenditure often differed for brief (2, 4, and 10 s) bouts of exercise, but this did not extend to total energy expenditure. At the higher exercise intensities with the longest durations O2 deficit, blood lactate concentration, and excess CO2 estimates of anaerobic and total energy expenditure revealed high variability; however, they were not statistically different. Moreover, they all differed significantly from the O2 debt interpretation (p < 0.05). It is concluded that as the contribution of rapid substrate-level ATP turnover with lactate production becomes larger, the greatest error in quantifying total energy expenditure is suggested to occur not with the method of estimation, but with the omission of a reasonable estimate of anaerobic energy expenditure.Key words: O2 deficit, lactate, O2 debt, EPOC, anaerobic energy expenditure.

Download Full-text

Correlation of Plasma Phenformin Concentration with Metabolic Effects in Normal Subjects

Clinical Science ◽

10.1042/cs0580153 ◽

1980 ◽

Vol 58 (2) ◽

pp. 153-155 ◽

Cited By ~ 5

Author(s):

M. Nattrass ◽

Karen Sizer ◽

K. G. M. M. Alberti

Keyword(s):

Blood Glucose ◽

Plasma Concentration ◽

Blood Lactate ◽

Serum Insulin ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Normal Subjects ◽

Metabolic Effects ◽

Intermediary Metabolites ◽

Pyruvate Ratio

1. Circulating concentrations of intermediary metabolites have been measured after administration of 50 mg of phenformin to normal subjects. 2. Phenformin caused a significant increase in blood lactate, alanine and the lactate/pyruvate ratio but did not affect blood glucose or serum insulin concentrations. 3. There was a significant correlation between the increase in blood lactate concentration after phenformin and the plasma concentration of the drug.

Download Full-text

Lactate kinetics at the lactate threshold in trained and untrained men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00043.2013 ◽

2013 ◽

Vol 114 (11) ◽

pp. 1593-1602 ◽

Cited By ~ 56

Author(s):

Laurent A. Messonnier ◽

Chi-An W. Emhoff ◽

Jill A. Fattor ◽

Michael A. Horning ◽

Thomas J. Carlson ◽

...

Keyword(s):

Endurance Training ◽

Lactate Threshold ◽

Lactate Concentration ◽

Lactate Production ◽

Blood Lactate Concentration ◽

Metabolic Clearance ◽

Metabolic Clearance Rate ◽

Trained Subjects ◽

Lactate Kinetics ◽

Power Outputs

To understand the meaning of the lactate threshold (LT) and to test the hypothesis that endurance training augments lactate kinetics [i.e., rates of appearance and disposal (Ra and Rd, respectively, mg·kg−1·min−1) and metabolic clearance rate (MCR, ml·kg−1·min−1)], we studied six untrained (UT) and six trained (T) subjects during 60-min exercise bouts at power outputs (PO) eliciting the LT. Trained subjects performed two additional exercise bouts at a PO 10% lower (LT-10%), one of which involved a lactate clamp (LC) to match blood lactate concentration ([lactate]b) to that achieved during the LT trial. At LT, lactate Ra was higher in T (24.1 ± 2.7) than in UT (14.6 ± 2.4; P < 0.05) subjects, but Ra was not different between UT and T when relative exercise intensities were matched (UT-LT vs. T-LT-10%, 67% V̇o2max). At LT, MCR in T (62.5 ± 5.0) subjects was 34% higher than in UT (46.5 ± 7.0; P < 0.05), and a reduction in PO resulted in a significant increase in MCR by 46% (LT-10%, 91.5 ± 14.9, P < 0.05). At matched relative exercise intensities (67% V̇o2max), MCR in T subjects was 97% higher than in UT ( P < 0.05). During the LC trial, MCR in T subjects was 64% higher than in UT ( P < 0.05), in whom %V̇o2max and [lactate]b were similar. We conclude that 1) lactate MCR reaches an apex below the LT, 2) LT corresponds to a limitation in MCR, and 3) endurance training augments capacities for lactate production, disposal and clearance.

Download Full-text

Physiological Response to Different Kata Performances

Acta Facultatis Educationis Physicae Universitatis Comenianae ◽

10.2478/afepuc-2021-0002 ◽

2021 ◽

Vol 61 (1) ◽

pp. 14-23

Author(s):

Dušana Augustovičová ◽

Radovan Hadža ◽

Rastislav Štyriak ◽

Peter Barinec

Keyword(s):

Heart Rate ◽

Blood Lactate ◽

Physiological Response ◽

Body Height ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Energy System ◽

Mean Values ◽

National Team ◽

Significant Difference

Summary During a karate competition, a competitor in the kata discipline may choose one kata of 102 katas on the list. This kata must not be repeated. Katas differ in duration, complexity, number of fast and slow techniques, which also means different intensity, physiological response of the karateka body and energy coverage. Problems and Aim. In our study, we focused on the identification and assessment of the duration and difficulty of selected katas by monitoring the internal response of the human body (heart rate, lactate) of three top women´s Slovak national team karate competitors of kata individual categories during training and competition. Methods. The research sample consisted of 3 karate kata athletes (age 17.3 years, body height 161.7 cm, body weight 55.7 kg), who trained kata on average 7 years. To evaluate the indicators of the internal body load in selected katas we used mean, standard deviation, min-max. Results. The highest mean maximum heart rate values athletes had during performance kata Gojushi Ho (187 ± 8.2 bpm). The highest average heart rate values were observed during performance kata Chatanyara Kushanku (171 ± 9.9). Similarly, we found the highest mean values of blood lactate 4 minutes after performance kata Chatanyara Kushanku. (7.6 ± 2.5 mmol.l-1). The longest duration had the kata Suparinpei (204 ± 13 s). There was a significant difference in level of blood lactate reached in different katas (p ≤ 0.05) and the duration of katas. Conclusions. The duration of 5 most common katas used at the high level competition is different (p ≤ 0.05), thus the intensity expressed by the frequency of the techniques, and heart rate and blood lactate concentration. ATP-PCr energy system seems to be the major contributor while contribution of the aerobic energy system rises with the increase in duration of kata.

Download Full-text