Physiological responses during prolonged exercise at the power output corresponding to the blood lactate threshold

1990 ◽  
Vol 60 (4) ◽  
pp. 239-243 ◽  
Author(s):  
P. Mognoni ◽  
M. D. Sirtori ◽  
F. Lorenzelli ◽  
P. Cerretelli
Keyword(s):  
Blood Lactate ◽  
Power Output ◽  
Lactate Threshold ◽  
Prolonged Exercise ◽  
Physiological Responses

Comparison of Power Outputs During Time Trialing and Power Outputs Eliciting Metabolic Variables in Cycle Ergometry

2010 ◽  
Vol 20 (2) ◽  
pp. 115-121
Author(s):  
David Michael Morris ◽  
Rebecca Susan Shafer
Keyword(s):  
Steady State ◽  
Blood Lactate ◽  
Power Output ◽  
Lactate Threshold ◽  
Time Trial ◽  
Cycle Ergometry ◽  
Moderate Altitude ◽  
Maximal Lactate Steady State ◽  
Metabolic Variables ◽  
Power Outputs

The authors sought to compare power output at blood lactate threshold, maximal lactate steady state, and pH threshold with the average power output during a simulated 20-km time trial assessed during cycle ergometry. Participants (N = 13) were trained male and female cyclists and triathletes, all permanent residents at moderate altitude (1,525–2,225 m). Testing was performed at 1,525 or 1,860 m altitude. Power outputs were determined during a simulated 20-km time trial (PTT), at blood pH threshold (PpHT), at maximal lactate steady state (PMLSS), and at blood lactate threshold determined by 2 methods: the highest power output that did not result in consecutive and continued increases in blood lactate concentrations from exercising baseline (PLT) and the highest power output that did not result in consecutive and continued increases of ≥1 mmol/L in blood lactate concentrations from exercising baseline (PLT1). PLT, PLT1, and PMLSS were all significantly lower than PpHT (p < .05) and PTT (p < .05). No significant difference was observed between PpHT and PTT (p > .05). Significant correlations were observed between each of the metabolic variables, PLT, PLT1, PMLSS, and PpHT, compared with PTT (p < .05). The authors conclude that, of the 4 metabolic variables, only PpHT offered an accurate reflection of PTT.

Psychomotor performance during prolonged exercise above and below the blood lactate threshold

1997 ◽  
Vol 77 (1-2) ◽  
pp. 77-80 ◽  
Author(s):  
J. Chmura ◽  
H. Krysztofiak ◽  
A. W. Ziemba ◽  
K. Nazar ◽  
H. Kaciuba-Uścilko
Keyword(s):  
Blood Lactate ◽  
Psychomotor Performance ◽  
Lactate Threshold ◽  
Prolonged Exercise

Caffeine supplementation for 4-day, followed by acute ingestion, did not impact triathlete output power after submaximal intensity exercise

2019 ◽  
Vol 18 (3) ◽  
pp. 118
Author(s):  
Anderson Pontes Morales ◽  
Felipe Sampaio-Jorge ◽  
Thiago Barth ◽  
Alessandra Alegre De Matos ◽  
Luiz Felipe Da Cruz Rangel ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Output Power ◽  
Body Mass ◽  
Effect Size ◽  
Power Output ◽  
Anaerobic Power ◽  
Lactate Concentration ◽  
Wingate Test ◽  
Large Effect Size ◽  
Acute Ingestion

Introduction: The aim of this study was to test the hypothesis that caffeine supplementation (6 mg·kg-1 body mass) for 4-days, followed by acute intake, would impact five male triathletes output power after performed submaximal intensity exercise. Methods: This was a randomized, double-blind, placebo-controlled crossover study, placebo (4-day) - placebo (acute) PP, placebo (4-days) -caffeine (acute) PC, and caffeine (4-day) - caffeine (acute) CC. Participants abstained from dietary caffeine sources for 4 days and ingested capsules containing either placebo or caffeine (6 mg.kg-1 body mass day in one absorption). The acute trials the capsules containing placebo or caffeine (6 mg.kg-1 body mass day in one absorption) were ingested 60min before completing exercise in a treadmill for 40min (80% VO2max) and to perform the Wingate test. Results: Blood lactate was determined before, 60min after ingestion, and immediately after the exercise on the treadmill, the Wingate test, and after the recovery (10-min). CC and PC trials did not change the cardiopulmonary variables (P>0.05) and the anaerobic power variables (peak/mean power output and fatigue index) (P>0.05). The PC trial compared with PP promoted improvements in the curve power output in 2 sec by 31.19% (large effect-size d = 1.08; P<0.05) and 3 sec by 20% (large effect-size d = 1.19; P<0.05). A 10min recovery was not sufficient to reduce blood lactate concentration in the PC trial compared with PP (PC, 13.73±2.66 vs. PP, 10.26±1.60 mmol.L-1; P<0.05, respectively) (P<0.05). Conclusion: In conclusion, these results indicate that caffeine supplementation (6 mg·kg-1 body mass) for 4 days, followed by acute ingestion, did not impact the triathletes output power after performed submaximal intensity exercise. Nutritional interventions may help researchers and athletes to adapt strategies for manipulating caffeine use.Key-words: caffeine metabolism, Wingate test, blood lactate, performance.

scholarly journals Adjustments of Cardiac Function During Prolonged Exercise Relative to Lactate Threshold.

1995 ◽  
Vol 14 (4) ◽  
pp. 177-182 ◽  
Author(s):  
Soo Hyun Kim ◽  
Kiyoji Tanaka ◽  
Yasuhito Kumazaki ◽  
Kou Mizuno ◽  
Masaki Takeda ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Lactate Threshold ◽  
Prolonged Exercise

Effect of inspired O2 concentration on leg lactate release during incremental exercise

1996 ◽  
Vol 81 (1) ◽  
pp. 246-251 ◽  
Author(s):  
D. R. Knight ◽  
D. C. Poole ◽  
M. C. Hogan ◽  
D. E. Bebout ◽  
P. D. Wagner
Keyword(s):  
Blood Lactate ◽  
Power Output ◽  
Incremental Exercise ◽  
Venous Blood Flow ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Lactate Accumulation ◽  
Lactate Release ◽  
O2 Concentration ◽  
Blood Lactate Accumulation

The normal rate of blood lactate accumulation during exercise is increased by hypoxia and decreased by hyperoxia. It is not known whether these changes are primarily determined by the lactate release in locomotory muscles or other tissues. Eleven men performed cycle exercise at 20, 35, 50, 92, and 100% of maximal power output while breathing 12, 21, and 100% O2. Leg lactate release was calculated at each stage of exercise as the product of femoral venous blood flow (thermodilution method) and femoral arteriovenous difference in blood lactate concentrations. Regression analysis showed that leg lactate release accounted for 90% of the variability in mean arterial lactate concentration at 20-92% maximal power output. This relationship was described by a regression line with a slope of 0.28 +/- 0.02 min/l and a y-intercept of 1.06 +/- 0.38 mmol/l (r2 = 0.90). There was no effect of inspired O2 concentration on this relationship (P > 0.05). We conclude that during continuous incremental exercise to fatigue the effect of inspired O2 concentration on blood lactate accumulation is principally determined by the rate of net lactate release in blood vessels of the locomotory muscles.

scholarly journals Physiological Responses and Predictors of Performance in a Simulated Competitive Ski Mountaineering Race

2021 ◽  
pp. 250-257
Author(s):  
Michael Lasshofer ◽  
John Seifert ◽  
Anna-Maria Wörndle ◽  
Thomas Stöggl
Keyword(s):  
Laboratory Test ◽  
Power Output ◽  
Ventilatory Threshold ◽  
Elite Athletes ◽  
Physiological Responses ◽  
Performance Parameters ◽  
Ramp Test ◽  
The Past ◽  
Treadmill Speed ◽  
And Performance

Competitive ski mountaineering (SKIMO) has achieved great popularity within the past years. However, knowledge about the predictors of performance and physiological response to SKIMO racing is limited. Therefore, 21 male SKIMO athletes split into two performance groups (elite: VO2max 71.2 ± 6.8 ml· min-1· kg-1 vs. sub-elite: 62.5 ± 4.7 ml· min-1· kg-1) were tested and analysed during a vertical SKIMO race simulation (523 m elevation gain) and in a laboratory SKIMO specific ramp test. In both cases, oxygen consumption (VO2), heart rate (HR), blood lactate and cycle characteristics were measured. During the race simulation, the elite athletes were approximately 5 min faster compared with the sub-elite (27:15 ± 1:16 min; 32:31 ± 2:13 min; p < 0.001). VO2 was higher for elite athletes during the race simulation (p = 0.046) and in the laboratory test at ventilatory threshold 2 (p = 0.005) and at maximum VO2 (p = 0.003). Laboratory maximum power output is displayed as treadmill speed and was higher for elite than sub-elite athletes (7.4 ± 0.3 km h-1; 6.6 ± 0.3 km h-1; p < 0.001). Lactate values were higher in the laboratory maximum ramp test than in the race simulation (p < 0.001). Pearson’s correlation coefficient between race time and performance parameters was highest for velocity and VO2 related parameters during the laboratory test (r > 0.6). Elite athletes showed their superiority in the race simulation as well as during the maximum ramp test. While HR analysis revealed a similar strain to both cohorts in both tests, the superiority can be explainable by higher VO2 and power output. To further push the performance of SKIMO athletes, the development of named factors like power output at maximum and ventilatory threshold 2 seems crucial.

scholarly journals Physiological aspects and energetic contribution in 20s:10s high-intensity interval exercise at different intensities

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9791
Author(s):  
Gabriel V. Protzen ◽  
Charles Bartel ◽  
Victor S. Coswig ◽  
Paulo Gentil ◽  
Fabricio B. Del Vecchio
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Power Output ◽  
High Intensity ◽  
Interval Training ◽  
Random Order ◽  
Peak Power Output ◽  
Maximal Heart Rate ◽  
Work Intensity ◽  
High Intensity Interval

Background One of the most popular high-intensity interval exercises is the called “Tabata Protocol”. However, most investigations have limitations in describing the work intensity, and this fact appears to be due to the protocol unfeasibility. Furthermore, the physiological demands and energetic contribution during this kind of exercise remain unclear. Methods Eight physically active students (21.8 ± 3.7 years) and eight well-trained cycling athletes (27.8 ± 6.4 years) were enrolled. In the first visit, we collected descriptive data and the peak power output (PPO). On the next three visits, in random order, participants performed interval training with the same time structure (effort:rest 20s:10s) but using different intensities (115%, 130%, and 170% of PPO). We collected the number of sprints, power output, oxygen consumption, blood lactate, and heart rate. Results The analysis of variance for multivariate test (number of sprints, power output, blood lactate, peak heart rate and percentage of maximal heart rate) showed significant differences between groups (F = 9.62; p = 0.001) and intensities (F = 384.05; p < 0.001), with no interactions (F = 0.94; p = 0.57). All three energetic contributions and intensities were different between protocols. The higher contribution was aerobic, followed by alactic and lactic. The aerobic contribution was higher at 115%PPO, while the alactic system showed higher contribution at 130%PPO. In conclusion, the aerobic system was predominant in the three exercise protocols, and we observed a higher contribution at lower intensities.

scholarly journals OR-049 Monitoring and evaluation of Zhejiang Swimmers’ Altitude Training

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Weiwei Lin
Keyword(s):  
Blood Lactate ◽  
Lactate Threshold ◽  
The Body ◽  
Monday Morning ◽  
Altitude Training ◽  
Training Plan ◽  
Before And After ◽  
The Mean ◽  
The Individual ◽  
Peak Value

Objective (1)Through the blood physiological and biochemical tests during the altitude training, to analyze the body function of swimmers in this stage.(2) Through the individual lactate threshold tests before and after the altitude training,to analyze the effects of altitude training. Methods Eight swimmers took a 26-day altitude training session.The individual lactate threshold test was carried out by the Swedish Monak839E power cycle progressive loading method before and after the training;During the altitude training period, 5ml of the subjects' elbow vein was extracted and tested on an empty stomach and in a quiet state every Monday morning. Results (1)When swimmers reached the plateau, the hemoglobin value was indistinguishable from the plain(male 156.2±7.01，female 135.7±8.75g/L),From the hemoglobin value (male 154.03 + 5.67, female 134.23 + 9.66g/L), there was a decrease in both male and female in the second week.But hypoxia stimulated red blood cell production, and the body itself was gradually adapting to the training load.Thus, the hemoglobin value of the third week (male 157.17 + 3.7, female 141.93 + 10.06g/L) was significantly improved, and higher than the level of the first week.During the altitude training period, the mean value of male’s blood testosterone was 474.33 + 97.06ng/dl, and the female’s blood testosterone was 33.67 + 17.25ng/dl.Male’s blood testosterone was lower than the mean of the national team, because the study participants were youngers who were not fully developed and had shorter training years.There were different trends in blood testosterone value between male and female. Male’s blood testosterone values during the Monday morning of these three weeks were 479.67±76.25、492.33±83.61、451±153.41ng/dl respectively.female’s blood testosterone values during the Monday morning of these three weeks were 29.33±21.83、32±23.26、39.67±9.29ng/dl respectively.These further indicated that this altitude training plan was more suitable for male with shorter training years, and the body had certain fatigue accumulation, but the decrease range was within a reasonable range.However, the increase of blood testosterone per week in female indicated that the training stimulation depth was not enough, and the potential of athletes should be further explored.According to the changes of creatine kinase, the sensitivity of male to the change of altitude training intensity was also shown, and the highest value of creatine kinase was 731U/L in the first week.(2) From the value of the individual lactate threshold before and after altitude training, no matter male or female,the change was not obvious, but was generally improved, this may be the altitude training adopted the pattern of three and a half weeks, training time was short.Secondly, as a professional athlete, the "plastic space" gradually decreased with the extension of the training years.Most of the peak blood lactate occurred in 1-3 minutes of recovery period.and the average value increased from 8.96 + 1.86mmol/L before altitude training to 9.99 + 1.47mmol/L.Among them, the peak value of male’s blood lactate was increased from 8 + 2.22mmol/L before the altitude training to 10.91 + 1.43mmol/L, and there was a significant difference in the peak of blood lactate before and after the altitude training.However, the peak value of female’s blood lactate was decreased from 9.92 + 0.79mmol/L before the altitude training to 9.07 + 0.88mmol/L. This was mainly due to the fact that a member of the swimmers had caused the result, and this swimmer’s enduring lactate level was lower than the one before the plateau. Conclusions The altitude training generally improved athletes’ training ability, but based on factors such as training age, gender, should be targeted according to the individual situation of each athlete training plan, so as to achieve more from less.

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