The Effect of Hyperventilation on the Lactacidaemia of Muscular Exercise

1970 ◽  
Vol 38 (2) ◽  
pp. 269-276 ◽  
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.

Acute anemia increases lactate production and decreases clearance during exercise

1989 ◽  
Vol 67 (2) ◽  
pp. 756-764 ◽  
Author(s):  
S. G. Gregg ◽  
R. S. Mazzeo ◽  
T. F. Budinger ◽  
G. A. Brooks
Keyword(s):  
Blood Glucose ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration ◽  
Flow Distribution ◽  
Plasma Catecholamine ◽  
Metabolic Clearance ◽  
Sprague Dawley ◽  
Mean Values

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)

Metabolic recovery from exhaustive activity by a large lizard

1980 ◽  
Vol 48 (4) ◽  
pp. 689-694 ◽  
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.

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

1994 ◽  
Vol 76 (2) ◽  
pp. 846-852 ◽  
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.

Does Prior 1500-m Swimming Affect Cycling Energy Expenditure in Well-Trained Triathletes?

2005 ◽  
Vol 30 (4) ◽  
pp. 392-403 ◽  
Author(s):  
Anne Delextrat ◽  
Jeanick Brisswalter ◽  
Christophe Hausswirth ◽  
Thierry Bernard ◽  
Jean-Marc Vallier
Keyword(s):  
Energy Expenditure ◽  
Blood Lactate ◽  
Energy Demand ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Exercise Duration ◽  
Cycle Ergometer ◽  
Warm Up ◽  
Key Words Lactate ◽  
Pedaling Frequency

The purpose of this study was to determine the effects of a 1,500-m swim on energy expenditure during a subsequent cycle task. Eight well-trained male triathletes (age 26.0 ± 5.0 yrs; height 179.6 ± 4.5 cm; mass 71.3 ± 5.8 kg; [Formula: see text] 71.9 ± 7.8 ml kg−1•min−1) underwent two testing sessions in counterbalanced order. The sessions consisted of a 30-min ride on the cycle ergometer at 75% of maximal aerobic power (MAP), and at a pedaling frequency of 95 rev•min−1, preceded either by a 1,500-m swim at 1.20 m•s−1 (SC trial) or by a cycling warm-up at 30% of MAP (C trial). Respiratory and metabolic data were collected between the 3rd and the 5th min, and between the 28th and 30th min of cycling. The main results indicated a significantly lower gross efficiency (13.0%) and significantly higher blood lactate concentration (56.4%), [Formula: see text] (5.0%), HR (9.3%), [Formula: see text] (15.7%), and RF (19.9%) in the SC compared to the C trial after 5 min, p <  0.05. After 30 min, only [Formula: see text] (7.9%) and blood lactate concentration (43.9%) were significantly higher in the SC compared to the C trial, p <  0.05. These results confirm the increase in energy cost previously observed during sprint-distance triathlons and point to the importance of the relative intensity of swimming on energy demand during subsequent cycling. Key words: lactate, oxygen uptake, intensity, exercise duration, performance

Correlation of competition performance with heart rate and blood lactate response during interval training sessions in eventing horses

2019 ◽  
Vol 15 (3) ◽  
pp. 187-197 ◽  
Author(s):  
K. Kirsch ◽  
M. Düe ◽  
H. Holzhausen ◽  
C. Sandersen
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Performance Monitoring ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Interval Training ◽  
Exercise Tests ◽  
Post Exercise ◽  
Exponential Regression ◽  
The Difference

Objective performance monitoring in eventing horses is rare as the implementation of standardised exercise tests is commonly perceived to interfere with the daily training routine. The validity of performance parameters derived from GPS data, heart rate (HR) and post exercise blood lactate concentration (LAC) measured during usual training sessions should therefore be evaluated. Velocity (V), HR and post exercise LAC recorded during 172 interval training sessions in 30 horses were retrospectively analysed. Linear regression of HR, averaged over retrospectively defined speed ranges, was used to calculate the V at HRs of 150 (V150) and 200 (V200) beats/min. A single exponential regression model, fitted to LAC in relation to HR values from the whole group of horses, was used to predict LAC for each horse’s individual HR value and to calculate the difference between measured and predicted LAC (LACdiff). Recovery HRs were derived from bi-exponential regression of HR decrease after exercise. Results were compared between different stages of training in the same horses and between horses categorised as superior (SP) and average performer (AP) according to their competition performance. V150 and V200 significantly increased with progressing training. SP had higher V150 and V200 values, lower LACdiff values and lower HRs after 1 min of recovery (HRR60s) than AP. Competition performance was positively correlated to V150 and V200 but negatively correlated to LACdiff and HRR60s. Regular monitoring of HR and LAC in response to interval training provided valuable indicators of performance. The results of this study may contribute to an increased applicability of routine performance monitoring in eventing horses.

Heart-Rate Acceleration Is Linearly Related to Anaerobic Exercise Performance

2021 ◽  
pp. 1-5
Author(s):  
Noah M.A. d’Unienville ◽  
Maximillian J. Nelson ◽  
Clint R. Bellenger ◽  
Henry T. Blake ◽  
Jonathan D. Buckley
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Exercise Performance ◽  
Average Power ◽  
Lactate Concentration ◽  
Anaerobic Capacity ◽  
Blood Lactate Concentration ◽  
Cycle Ergometer ◽  
Anaerobic Exercise ◽  
Peak Power Output

Purpose: To prescribe training loads to improve performance, one must know how an athlete is responding to loading. The maximal rate of heart-rate increase (rHRI) during the transition from rest to exercise is linearly related to changes in endurance exercise performance and can be used to infer how athletes are responding to changes in training load. Relationships between rHRI and anaerobic exercise performance have not been evaluated. The objective of this study was to evaluate relationships between rHRI and anaerobic exercise performance. Methods: Eighteen recreational strength and power athletes (13 male and 5 female) were tested on a cycle ergometer for rHRI, 6-second peak power output, anaerobic capacity (30-s average power), and blood lactate concentration prior to (PRE), and 1 (POST1) and 3 (POST3) hours after fatiguing high-intensity interval cycling. Results: Compared with PRE, rHRI was slower at POST1 (effect size [ES] = −0.38, P = .045) but not POST3 (ES = −0.36, P = .11). PPO was not changed at POST1 (ES = −0.12, P = .19) but reduced at POST3 (ES = −0.52, P = .01). Anaerobic capacity was reduced at POST1 (ES = −1.24, P < .001) and POST3 (ES = −0.83, P < .001), and blood lactate concentration was increased at POST1 (ES = 1.73, P < .001) but not at POST3 (ES = 0.75, P = .11). rHRI was positively related to PPO (B = 0.19, P = .03) and anaerobic capacity (B = 0.14, P = .005) and inversely related to blood lactate concentration (B = −0.22, P = .04). Conclusions: rHRI is linearly related to acute changes in anaerobic exercise performance and may indicate how athletes are responding to training to guide the application of training loads.

Estimating energy expenditure for brief bouts of exercise with acute recovery

2006 ◽  
Vol 31 (2) ◽  
pp. 144-149 ◽  
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.

scholarly journals Differences in Physiological and Perceptual Responses to High Intensity Interval Exercise Between Arm and Leg Cycling

2021 ◽  
Vol 12 ◽  
Author(s):  
Todd A. Astorino ◽  
Danielle Emma
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
High Intensity ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cycle Ergometer ◽  
Affective Valence ◽  
Interval Exercise ◽  
Leg Cycling ◽  
High Intensity Interval

This study compared changes in oxygen uptake (VO2), heart rate (HR), blood lactate concentration (BLa), affective valence, and rating of perceived exertion (RPE) between sessions of high intensity interval exercise (HIIE) performed on the arm (ACE) and leg cycle ergometer (LCE). Twenty three active and non-obese men and women (age and BMI=24.7±5.8year and 24.8±3.4kg/m2) initially underwent graded exercise testing to determine VO2max and peak power output (PPO) on both ergometers. Subsequently on two separate days, they performed 10 1min intervals of ACE or LCE at 75 %PPO separated by 1min of active recovery at 10 %PPO. Gas exchange data, HR, and perceptual responses were obtained continuously and blood samples were acquired pre- and post-exercise to assess the change in BLa. VO2max and PPO on the LCE were significantly higher (p&lt;0.001) than ACE (37.2±6.3 vs. 26.3±6.6ml/kg/min and 259.0±48.0 vs. 120.0±48.1W). Mean VO2 (1.7±0.3 vs. 1.1±0.3L/min, d=2.3) and HR (149±14 vs. 131±17 b/min, d=2.1) were higher (p&lt;0.001) in response to LCE vs. ACE as was BLa (7.6±2.6 vs. 5.3±2.5mM, d=2.3), yet there was no difference (p=0.12) in peak VO2 or HR. Leg cycling elicited higher relative HR compared to ACE (81±5 vs. 75±7 %HRmax, p=0.01), although, there was no difference in relative VO2 (63±6 vs. 60±8 %VO2max, p=0.09) between modes. Affective valence was lower during LCE vs. ACE (p=0.003), although no differences in enjoyment (p=0.68) or RPE (p=0.59) were demonstrated. Overall, HIIE performed on the cycle ergometer elicits higher relative heart rate and blood lactate concentration and a more aversive affective valence, making these modes not interchangeable in terms of the acute physiological and perceptual response to interval based exercise.

scholarly journals A method for calculating lactate production rate using blood lactate concentration during exercise in mice

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Reo Takeda ◽  
Yudai Nonaka ◽  
Katsuyuki Kakinoki ◽  
Yutaka Kano ◽  
Daisuke Hoshino
Keyword(s):  
Production Rate ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration

Lactate clamp: a method to measure lactate utilization in vivo

1998 ◽  
Vol 275 (4) ◽  
pp. E729-E733 ◽  
Author(s):  
Jiaping Gao ◽  
Mohammad A. Islam ◽  
Christine M. Brennan ◽  
Beth E. Dunning ◽  
James E. Foley
Keyword(s):  
Blood Lactate ◽  
Infusion Rate ◽  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration ◽  
Whole Body ◽  
Lactate Utilization ◽  
Lactate Infusion ◽  
And Control

A lactate clamp method has been developed to quantify the whole body lactate utilization in conscious, unstressed rats. Dichloroacetate (DCA), a known lactate utilization enhancer, was used to validate the method. Fasting blood lactate concentrations before the clamps were identical for DCA-treated (1 mmol/kg) and control groups (1.65 ± 0.37 vs. 1.65 ± 0.19 mM). The animals received a primed continuous lactate infusion for 90 min at variable rates to clamp the blood lactate concentration at 2 mM. The steady-state (60–90 min) lactate infusion rate, which represents the whole body lactate utilization in DCA-treated animals, was 144% higher than that in the control animals (13.2 ± 1.0 vs. 5.4 ± 1.1 mg ⋅ kg−1 ⋅ min−1; P < 0.001). The markedly increased lactate infusion rate indicates an enhanced lactate flux by DCA. To determine whether the increased lactate infusion by DCA reflected reduced endogenous lactate production, lactate production was measured. The results indicate that endogenous lactate production was not affected by DCA. In conclusion, the lactate clamp provides a sensitive and reliable method to assess lactate utilization in vivo, a dynamic measurement that may not be clearly demonstrated by blood lactate concentrations per se.

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