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.

scholarly journals The Maximal Lactate Steady State Workload Determines Individual Swimming Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Gernot O. Hering ◽  
Jens Stepan
Keyword(s):  
Steady State ◽  
Blood Lactate ◽  
Swimming Speed ◽  
Lactate Threshold ◽  
Swimming Performance ◽  
Endurance Capacity ◽  
Sudden Increase ◽  
Maximal Lactate Steady State ◽  
Custom Made ◽  
Major Interest

The lactate threshold (LT) and the strongly related maximal lactate steady state workload (MLSSW) are critical for physical endurance capacity and therefore of major interest in numerous sports. However, their relevance to individual swimming performance is not well understood. We used a custom-made visual light pacer for real-time speed modulation during front crawl to determine the LT and MLSSW in a single-exercise test. When approaching the LT, we found that minute variations in swimming speed had considerable effects on blood lactate concentration ([La−]). The LT was characterized by a sudden increase in [La−], while the MLSSW occurred after a subsequent workload reduction, as indicated by a rapid cessation of blood lactate accumulation. Determination of the MLSSW by this so-called “individual lactate threshold” (ILT)-test was highly reproducible and valid in a constant speed test. Mean swimming speed in 800 and 1,500 m competition (S-Comp) was 3.4% above MLSSW level and S-Comp, and the difference between S-Comp and the MLSSW (Δ S-Comp/MLSSW) were higher for long-distance swimmers (800–1,500 m) than for short- and middle-distance swimmers (50–400 m). Moreover, Δ S-Comp/MLSSW varied significantly between subjects and had a strong influence on overall swimming performance. Our results demonstrate that the MLSSW determines individual swimming performance, reflects endurance capacity in the sub- to supra-threshold range, and is therefore appropriate to adjust training intensity in moderate to severe domains of exercise.

Exercise slightly above the maximal lactate steady state reduces self-efficacy and increases negative affect

2019 ◽  
Author(s):  
James Graeme Wrightson ◽  
Louis Passfield
Keyword(s):  
Steady State ◽  
Negative Affect ◽  
Power Output ◽  
Self Efficacy ◽  
Repeated Measures ◽  
Physiological State ◽  
Constant Load ◽  
Peak Power Output ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State

Objectives: To examine the effect of exercise at and slightly above the maximal lactate steady state (MLSS) on self-efficacy, affect and effort, and their associations with exercise tolerance.Design: Counterbalanced, repeated measures designMethod: Participants performed two 30‐minute constant‐load cycling exercise at a power output equal to that at MLSS and 10 W above MLSS, immediately followed by a time‐to‐exhaustion test at 80% of their peak power output. Self-efficacy, affect and effort were measured before and after 30 minutes of cycling at and above MLSS.Results: Negative affect and effort higher, and self-efficacy and time to exhaustion were reduced, following cycling at MLSS + 10 W compared to cycling at the MLSS. Following exercise at the MLSS self-efficacy, affect and effort were all associated with subsequent time-to exhaustion. However, following exercise at MLSS + 10 W, only affect was associated with time-to exhaustion. Conclusions: Self efficacy, affect and effort are profoundly affected by physiological state, highlighting the influence of somatic states on perceptions and emotions during exercise. The affective response to exercise appears to be associated with exercise tolerance, indicating that the emotional, as well as physiological, responses should be considered when prescribing exercise training.

Slight power output manipulations around the maximal lactate steady state have an impact on fatigue in females and males.

2021 ◽  
Author(s):  
Rafael de Almeida Azevedo ◽  
Jonas Forot ◽  
Danilo Iannetta ◽  
Martin J. MacInnis ◽  
Guillaume Y. Millet ◽  
...  
Keyword(s):  
Steady State ◽  
Power Output ◽  
Contractile Function ◽  
Femoral Nerve ◽  
Peak Torque ◽  
Knee Extensors ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State ◽  
Subsequent Performance ◽  
Single Twitch

Neuromuscular fatigue (NMF) and exercise performance are affected by exercise intensity and sex differences. However, whether slight changes in power output (PO) below and above the maximal lactate steady-state (MLSS) impact NMF and subsequent performance (time to exhaustion, TTE) is unknown. Purpose: This study compared NMF and TTE in females and males in response to exercise performed at MLSS, 10 W below (MLSS-10) and above (MLSS+10). Methods: Twenty participants (9 females) performed three 30-min constant-PO exercise bouts followed (1 min delay) by a TTE at 80% of the peak-PO. NMF was characterized by isometric maximal voluntary contractions (IMVC) and femoral nerve electrical stimulation of knee extensors [e.g. peak torque of potentiated high-frequency (Db100) and single twitch (TwPt)] before and immediately after the constant-PO and TTE bouts. Results: IMVC declined less after MLSS-10 (-18±10%) compared to MLSS (-26±14%) and MLSS+10 (-31±11%) (all p<0.05), and the Db100 decline was greater after MLSS+10 (-24±14%) compared to the other intensities (MLSS-10: -15±9%; MLSS: -18±11%) (all p<0.05). Females showed smaller reductions in IMVC and TwPt compared to males after constant-PO bouts (all p<0.05), this difference being not dependant on intensity. TTE was negatively impacted by increasing the PO in the constant-PO (p<0.001), with no differences in end-exercise NMF (p>0.05). Conclusion: Slight changes in PO around MLSS elicited great changes in the reduction of maximal voluntary force and impairments in contractile function. Although NMF was lower in females compared to males, the changes in PO around the MLSS impacted both sexes similarly.

Maximal Lactate Steady State Rowing Intensity can be Predicted by a 6-Km Rowing Time Trial

2004 ◽  
Vol 36 (Supplement) ◽  
pp. S43-S44
Author(s):  
Margaret J. Gutilla ◽  
Craig O. Mattern ◽  
Maxi Meissner ◽  
Katie D. Bouton ◽  
Timothy E. Kirby ◽  
...  
Keyword(s):  
Steady State ◽  
Time Trial ◽  
Maximal Lactate Steady State

O2 uptake kinetics and the O2 deficit as related to exercise intensity and blood lactate

1993 ◽  
Vol 75 (2) ◽  
pp. 755-762 ◽  
Author(s):  
T. J. Barstow ◽  
R. Casaburi ◽  
K. Wasserman
Keyword(s):  
Blood Lactate ◽  
Time Constant ◽  
Exercise Intensity ◽  
Power Output ◽  
Cycle Ergometer ◽  
O2 Uptake ◽  
Ergometer Exercise ◽  
Lactate Levels ◽  
Power Outputs ◽  
O2 Deficit

The dynamic responses of O2 uptake (VO2) to a range of constant power output levels were related to exercise intensity [as percent maximal VO2 and as below vs. above lactic acid threshold (LAT)] and to the associated end-exercise lactate in three groups of subjects: group I, untrained subjects performing leg cycle ergometer exercise; group II, the same subjects performing arm cycle exercise; and group III, trained cyclists performing leg cycle ergometer exercise. Responses were described by a double-exponential equation, with each component having an independent time delay, which reduced to a monoexponential description for moderate (below-LAT) exercise. When a second exponential component to the VO2 response was present, it did not become evident until approximately 80–100 s into exercise. An overall time constant (tau T, determined as O2 deficit for the total response divided by net end-exercise VO2) and a primary time constant (tau P, determined from the O2 deficit and the amplitude for the early primary VO2 response) were compared. The tau T rose with power output and end-exercise lactate levels, but tau P was virtually invariant, even at high end-exercise lactate levels. Moreover the gain of the primary exponential component (as delta VO2/delta W) was constant across power outputs and blood lactate levels, suggesting that the primary VO2 response reflects a linear system, even at higher power outputs. These results suggest that elevated end-exercise lactate is not associated with any discernible slowing of the primary rise in VO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Time to exhaustion at intermittent maximal lactate steady state is longer than continuous cycling exercise

2012 ◽  
Vol 37 (6) ◽  
pp. 1047-1053 ◽  
Author(s):  
Talita Grossl ◽  
Ricardo Dantas de Lucas ◽  
Kristopher Mendes de Souza ◽  
Luiz Guilherme Antonacci Guglielmo
Keyword(s):  
Steady State ◽  
Endurance Training ◽  
Intermittent Exercise ◽  
Cycle Ergometer ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State ◽  
Continuous Exercise ◽  
Physiological Variables ◽  
Metabolic Variables ◽  
Work Done

The maximal lactate steady state (MLSS) represents a submaximal intensity that may be important in prescribing both continuous and interval endurance training. This study compared time to exhaustion (TTE) at MLSS in continuous and intermittent (i.e., with pauses) exercise, investigating whether physiological variables differ between these exercise modes. Fourteen trained male cyclists volunteered for this investigation and performed an incremental test, several 30-min tests to determine two MLSS intensities (continuous and discontinuous protocol), and two randomized tests until exhaustion at MLSS intensities on a cycle ergometer. The intermittent or discontinuous protocol was performed using 5 min of cycling, with an interval of 1 min of passive rest. TTE at intermittent MLSS was 24% longer than TTE at continuous exercise (67.8 ± 14.3 min vs. 54.7 ± 10.9 min; p < 0.05; effect sizes = 1.04), even though the absolute power output of intermittent MLSS was higher than continuous (268 ± 29 W vs. 251 ± 29 W; p < 0.05). Additionally, the total mechanical work done was significantly lower at continuous exercise than at intermittent exercise. Likewise, regarding cardiorespiratory and metabolic variables, we observed greater responses during intermittent exercise than during continuous exercise at MLSS. Thus, for endurance training prescription, this is an important finding to apply in extensive interval sessions at MLSS. This result suggests that interval sessions at discontinuous MLSS should be used instead of continuous MLSS, as discontinuous MLSS allows for a larger amount of total work during the exhaustion trial.

Reliability of time-to-exhaustion and selected psycho-physiological variables during constant-load cycling at the maximal lactate steady-state

2017 ◽  
Vol 42 (2) ◽  
pp. 142-147 ◽  
Author(s):  
Oliver Faude ◽  
Anne Hecksteden ◽  
Daniel Hammes ◽  
Franck Schumacher ◽  
Eric Besenius ◽  
...  
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Constant Load ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State ◽  
Physiological Variables ◽  
Load Tests

The maximal lactate steady-state (MLSS) is frequently assessed for prescribing endurance exercise intensity. Knowledge of the intra-individual variability of the MLSS is important for practical application. To date, little is known about the reliability of time-to-exhaustion and physiological responses to exercise at MLSS. Twenty-one healthy men (age, 25.2 (SD 3.3) years; height, 1.83 (0.06) m; body mass, 78.9 (8.9) kg; maximal oxygen uptake, 57.1 (10.7) mL·min−1·kg−1) performed 1 incremental exercise test, and 2 constant-load tests to determine MLSS intensity. Subsequently, 2 open-end constant-load tests (MLSS 1 and 2) at MLSS intensity (3.0 (0.7) W·kg−1, 76% (10%) maximal oxygen uptake) were carried out. During the tests, blood lactate concentrations, heart rate, ratings of perceived exertion (RPE), variables of gas exchange, and core body temperature were determined. Time-to-exhaustion was 50.8 (14.0) and 48.2 (16.7) min in MLSS 1 and 2 (mean change: −2.6 (95% confidence interval: −7.8, 2.6)), respectively. The coefficient of variation (CV) was high for time-to-exhaustion (24.6%) and for mean (4.8 (1.2) mmol·L−1) and end (5.4 (1.7) mmol·L−1) blood lactate concentrations (15.7% and 19.3%). The CV of mean exercise values for all other parameters ranged from 1.4% (core temperature) to 8.3% (ventilation). At termination, the CVs ranged from 0.8% (RPE) to 11.8% (breathing frequency). The low reliability of time-to-exhaustion and blood lactate concentration at MLSS indicates that the precise individual intensity prescription may be challenging. Moreover, the obtained data may serve as reference to allow for the separation of intervention effects from random variation in our sample.

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