Continuous increase in blood lactate concentration during different ramp exercise protocols

1989 ◽  
Vol 66 (3) ◽  
pp. 1104-1107 ◽  
Author(s):  
M. E. Campbell ◽  
R. L. Hughson ◽  
H. J. Green

The applicability of a continuous model description of the blood lactate concentration [( La-]) vs. O2 uptake (VO2) relationship was studied in nine healthy male volunteers during three different ramp exercise protocols. The work rate was increased at either 8, 15, or 50 W/min. The continuous model for [La-] = a + b exp(cVO2) was compared statistically with a previously proposed log-log transformation model for the [La-] and VO2 variables. It was found that the mean square error was significantly less for the continuous as opposed to the log-log model (P less than 0.01) by analysis of variance pooled across all three ramp slopes. The mean square errors from the individual ramp slopes were also significantly less for the continuous model by paired t test (P less than 0.05). It was observed that the major contributor to the increased error of the log-log model was at VO2's at or above the intersection point (lactate threshold) of the two linear log-transformed segments. The log-log transformation does not appear to relate to any physiological process. The lactate slope index, taken as the point where the slope of the relationship between [La-] and VO2 (i.e., d[La-]/dVO2) equaled 1, occurred at a mean VO2 of 2.25 and 2.37 l/min for the 15- and 8-W/min ramp slopes, respectively, but at 2.76 l/min for the 50-W/min ramp (P less than 0.05). It is concluded that [La-] increases as a continuous function with respect to VO2 across a wide range of ramp work rate slopes.

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.


1985 ◽  
Vol 58 (6) ◽  
pp. 2082-2089 ◽  
Author(s):  
L. B. Gladden ◽  
J. W. Yates ◽  
R. W. Stremel ◽  
B. A. Stamford

Twenty-four coded graph sets of gas exchange variables and blood lactate concentration (LA) plotted against time at 15-s intervals were analyzed by nine evaluators who determined the gas exchange (ATGE) and LA (ATLA) anaerobic thresholds. In addition, ATGE and ATLA were determined by a linear regression computer program. Agreement between ATGE and ATLA was poor; the median intraclass correlation coefficient (ri) was 0.53. Among evaluators, ATLA agreement (median ri = 0.81) was better than ATGE agreement (median ri = 0.70). In general, the ability of any evaluator to choose similar values from duplicate plots for either ATGE (median ri = 0.97) or ATLA (median ri = 0.995) was good. There was better agreement between the mean ATLA of the evaluators and the computer ATLA (ComLA) (ri = 0.88) than between the mean ATGE of the evaluators and the computer ATGE (ComVE), (ri = 0.58). Agreement between ComVE and ComLA was poor (ri = 0.29). These results suggest that ATGE does not accurately predict ATLA and that different evaluators choose different thresholds from the same data. Further assessment of the validity and precision of ATGE based on breath-by-breath and minute-by-minute data is needed.


1963 ◽  
Vol 18 (3) ◽  
pp. 619-622 ◽  
Author(s):  
Per-Olof Åstrand ◽  
Inger Hallbäck ◽  
Rune Hedman ◽  
Bengt Saltin

Blood was drawn from cross-country skiers at 1–3 min after the finish in competitions on distances from 10 to 85 km and the blood lactate determined. Despite a maximal effort of the skiers, accentuated at the end of the race, there was a successive decrease in the blood lactate concentration with work time. After a 10-km race, work time 35–36 min, the average was 139 mg/100 ml of blood (12.5 mEq/liter); after a 30-km race, with a time of 1 hr 50 min-1 hr 56 min, the mean value was 68 mg/100 ml (6.1 mEq/liter); and after a 50-km race, work time 3 hr 6 min-3 hr 18 min, 39 mg/100 ml (3.5 mEq/liter). A lactate concentration exceeding 100 mg/100 ml is a common finding after maximal muscular exercise involving large muscles. The explanation for the low values after prolonged maximal work, indicating a different kind of fatigue, is presently obscure. Data are presented on the oxygen uptake attained during skiing at actual racing speed (average Vo2 = 4.45 liters/min). Submitted on July 16, 1962


2017 ◽  
Vol 4 (05) ◽  
pp. 1318
Author(s):  
Asghar Nikseresht ◽  
Iman Yabande ◽  
Karamatollah Rahmanian ◽  
Abdolreza Sotoodeh Jahromi

Introduction: To avoid injuries during high-intensity sports training, it is important to recognize conditions of bodily consumption and production of adequate energy; exercise increases the concentration of the blood lactate. This paper is an attempt to compare pre and post lactate tolerance exercise test - blood lactate concentrations - of elite boy swimmers. Methods: Blood lactates are measured by an enzymatic method on 12 subjects 30 minutes before and adjust and 24 hours after the test. Results: The mean lactate concentration of 30.35±12.16 mg/dl is observed in swimmers 30 minutes before the test. Swimmers adjust after the test show mean blood lactate concentration of 108.52±18.17 mg/dl that is significantly higher than 30 minutes before the test (p<0.001). Then blood lactate level decreases below baseline level at 24 hours after the test. Conclusion: Blood lactate increases with the test and decreases below baseline within 24 hours after the test. 


2020 ◽  
Vol 24 (3) ◽  
pp. 137-142 ◽  
Author(s):  
R. Penov ◽  
P. Petrov ◽  
S. Kolimechkov

Background and Study Aim : Karate is going to take part in the Olympic games, for the first time in Tokyo 2020. The aim of this study was to analyse the changes in heart rate (HR) and blood lactate concentration of karate practitioners performing different katas in competitive conditions. Material and Methods : This study consisted of five elite male athletes (26.80±5.97 years), members of the Bulgarian national team in Shotokan karate, competing in the kata discipline. The study was conducted in competitive conditions during national competitions, in which three katas were performed by each of the competitors. Capillary blood lactate concentration (La) was determined at rest and after each kata. Heart rate (HR) was registered and physical activity was monitored by using three-dimensional accelerometers. Results: The mean La increased progressively after each following kata: 1.4±0.32 mmol/L at rest, 4.7±1.91 mmol/L after the first, 6.8±2.59 mmol/L after the second, and 7.1±2.35 mmol/L after the third kata. This increase was significant after the second (р<0.05) and third (р<0.01) kata, in comparison with the registered La at rest. The mean HR values reached 179±11.55 bpm during the first, 180±11.63 bpm during the second, and 181.5±15.44 bpm during the third kata. Conclusions: The La appeared to be a more informative parameter than heart rate, and the moderate increase of the La values (4-6 mmol/L) indicated optimal muscle tension and amplitude of moves when performing katas in competitive conditions. Further research is needed to determine the optimal La levels for the performance of different katas.


2007 ◽  
Vol 39 (Supplement) ◽  
pp. S345
Author(s):  
Yoko Sakai ◽  
Takuro Matsuda ◽  
Hideaki Kumahara ◽  
Akira Kiyonaga ◽  
Munehiro Shindo ◽  
...  

1998 ◽  
Vol 85 (6) ◽  
pp. 2118-2124 ◽  
Author(s):  
Veronique L. Billat ◽  
Ruddy Richard ◽  
Valerie M. Binsse ◽  
Jean P. Koralsztein ◽  
Philippe Haouzi

The purpose of this study was to examine the influence of the type of exercise (running vs. cycling) on the O2uptake (V˙o 2) slow component. Ten triathletes performed exhaustive exercise on a treadmill and on a cycloergometer at a work rate corresponding to 90% of maximalV˙o 2 (90% work rate maximalV˙o 2). The duration of the tests before exhaustion was superimposable for both type of exercises (10 min 37 s ± 4 min 11 s vs. 10 min 54 s ± 4 min 47 s for running and cycling, respectively). TheV˙o 2 slow component (difference between V˙o 2 at the last minute and minute 3 of exercise) was significantly lower during running compared with cycling (20.9 ± 2 vs. 268.8 ± 24 ml/min). Consequently, there was no relationship between the magnitude of theV˙o 2 slow component and the time to fatigue. Finally, because blood lactate levels at the end of the tests were similar for both running (7.2 ± 1.9 mmol/l) and cycling (7.3 ± 2.4 mmol/l), there was a clear dissociation between blood lactate and the V˙o 2slow component during running. These data demonstrate that 1) theV˙o 2 slow component depends on the type of exercise in a group of triathletes and 2) the time to fatigue is independent of the magnitude of theV˙o 2 slow component and blood lactate concentration. It is speculated that the difference in muscular contraction regimen between running and cycling could account for the difference in theV˙o 2 slow component.


1994 ◽  
Vol 77 (2) ◽  
pp. 684-691 ◽  
Author(s):  
R. L. Ge ◽  
Q. H. Chen ◽  
L. H. Wang ◽  
D. Gen ◽  
P. Yang ◽  
...  

To examine the hypothesis that the pathway of adaptation to high altitude in natives differs considerably from that in newcomers, we measured maximal O2 uptake (VO2max), minute ventilation, anaerobic threshold (AT), blood lactate, and blood gases during maximal exercise in 17 lifelong Tibetan residents and 14 acclimatized Han Chinese newcomers living at the altitude of 4,700 m. The two groups were similar in age, height, and weight, and the subjects were nonathletes. Although VO2max was significantly lower in the Tibetans than in the Hans (30.4 +/- 1.5 vs. 36.0 +/- 1.9 ml.min-1.kg-1 STPD; P < 0.05), at maximal exercise effort the exercise workload was greater (167.7 +/- 4.2 vs. 150.0 +/- 5.9 W; P < 0.05). The mean AT values (in % VO2max) in the Tibetan and Han subjects were 84.1 and 61.6%, respectively (P < 0.01). Minute ventilation at maximal exercise was significantly lower in the Tibetans than in the Hans (68.4 +/- 3.4 vs. 79.7 +/- 4.1 l/min BTPS; P < 0.05), whereas heart rate at maximal effort was equivalent in the two groups. The Tibetans showed lower blood lactate value than did the Hans both before and at the end of exercise. We conclude that the Tibetan natives have higher exercise performance and AT but lower VO2max and blood lactate concentration than do acclimatized Han newcomers. These results may reflect the effects of genetic or peripheral adaptation factors in the Tibetan natives.


1987 ◽  
Vol 62 (5) ◽  
pp. 1975-1981 ◽  
Author(s):  
R. L. Hughson ◽  
K. H. Weisiger ◽  
G. D. Swanson

The relationship between arterialized blood lactate concentration [( La-]) and O2 uptake (VO2) was examined during a total of 23 tests by eight subjects. Exercise was on a cycle ergometer with work rate incremented from loadless pedaling to exhaustion as a 50-W/min ramp function. Two different mathematical models were studied. One model employed a log-log transformation of [La-] and VO2 to yield [La-] threshold as proposed by Beaver et al. (J. Appl. Physiol. 59: 1936–1940, 1985). The other model was a continuous exponential plus constant of the form La- = a + b[exp(cVO2)]. In 21 of 23 data sets, the mean square error (MSE) of the continuous model was less than that of the log-log model (P less than 0.001). The MSE was on average 3.5 times greater in the log-log model than in the continuous model. The residuals were randomly distributed about the line of best fit for the continuous model. In contrast, the log-log model showed a nonrandom pattern indicating an inappropriate model. As an index of the position of the [La-]-VO2 continuous model, the VO2 at which the rate of increase of [La-] equaled the rate of increase of VO2 (d[La-]/dVO2 = 1) was determined. This VO2 was 2.241 +/- 0.081 l/min, which averaged 64.6% of maximal VO2. It is proposed that this lactate slope index could be used as a relative indicator of fitness instead of the previously applied threshold concept. The change in [La-] could be better described mathematically by a continuous model rather than the threshold model of Beaver et al.


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