Is the Functional Threshold Power Interchangeable With the Maximal Lactate Steady State in Trained Cyclists?

2019 ◽  
Vol 14 (8) ◽  
pp. 1029-1035 ◽  
Author(s):  
Fernando Klitzke Borszcz ◽  
Artur Ferreira Tramontin ◽  
Vitor Pereira Costa
Keyword(s):  
Steady State ◽  
Average Power ◽  
Time Trial ◽  
Constant Load ◽  
Threshold Power ◽  
Trained Group ◽  
Maximal Lactate Steady State ◽  
Pearson Coefficient ◽  
Large Correlation ◽  
Load Tests

Purpose: Functional threshold power (FTP), determined as 95% of the average power during a 20-min time trial, is suggested as a practical test for the determination of the maximal lactate steady state (MLSS) in cycling. Therefore, the objective of the present study was to determine the validity of FTP in predicting MLSS. Methods: A total of 15 cyclists, 7 classified as trained and 8 as well trained (mean [SD] maximal oxygen uptake 62.3 [6.4] mL·kg−1·min−1, maximal aerobic power 329 [30] W), performed an incremental test to exhaustion, an FTP test, and several constant-load tests to determine the MLSS. The bias ± 95% limits of agreement (LoA), typical error of the estimate (TEE), and Pearson coefficient of correlation (r) were calculated to assess validity. Results: For the power-output measures, FTP presented a bias ± 95% LoA of 1.4% ± 9.2%, a moderate TEE (4.7%), and nearly perfect correlation (r = .91) with MLSS in all cyclists together. When divided by training level, the bias ± 95% LoA and TEE were higher in the trained group (1.4% ± 11.8% and 6.4%, respectively) than in the well-trained group (1.3% ± 7.4% and 3.0%, respectively). For the heart-rate measurement, FTP presented a bias ± 95% LoA of −1.4% ± 8.2%, TEE of 4.0%, and very large correlation (r = .80) with MLSS. Conclusion: Therefore, trained and well-trained cyclists can use FTP as a noninvasive and practical alternative to estimate MLSS.

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.

scholarly journals Maximal Lactate Steady State Versus the 20-Minute Functional Threshold Power Test in Well-Trained Individuals: “Watts” the Big Deal?

2020 ◽  
Vol 15 (4) ◽  
pp. 541-547 ◽  
Author(s):  
Erin Calaine Inglis ◽  
Danilo Iannetta ◽  
Louis Passfield ◽  
Juan M. Murias
Keyword(s):  
Steady State ◽  
Field Test ◽  
Power Output ◽  
Constant Load ◽  
Test Series ◽  
Threshold Power ◽  
Maximal Lactate Steady State ◽  
Large Variability ◽  
Power Test ◽  
Induced Changes

Purpose: To (1) compare the power output (PO) for both the 20-minute functional threshold power (FTP20) field test and the calculated 95% (FTP95%) with PO at maximal lactate steady state (MLSS) and (2) evaluate the sensitivity of FTP95% and MLSS to training-induced changes. Methods: Eighteen participants (12 males: 37 [6] y and 6 females: 28 [6] y) performed a ramp-incremental cycling test to exhaustion, 2 to 3 constant-load MLSS trials, and an FTP20 test. A total of 10 participants returned to repeat the test series after 7 months of training. Results: The PO at FTP20 and FTP95% was greater than that at MLSS (P = .00), with the PO at MLSS representing 88.5% (4.8%) and 93.1% (5.1%) of FTP and FTP95%, respectively. MLSS was greater at POST compared with PRE training (12 [8] W) (P = .002). No increase was observed in mean PO at FTP20 and FTP95% (P = .75). Conclusions: The results indicate that the PO at FTP95% is different to MLSS, and that changes in the PO at MLSS after training were not reflected by FTP95%. Even when using an adjusted percentage (ie, 88% rather than 95% of FTP20), the large variability in the data is such that it would not be advisable to use this as a representation of MLSS.

scholarly journals Determination of the Maximal Lactate Steady State by HRV in Overweight and Obese Subjects

2019 ◽  
Vol 03 (02) ◽  
pp. E58-E64
Author(s):  
Tobias Schmidt ◽  
Sarah Wulff ◽  
Klaus-Michael Braumann ◽  
Ruediger Reer
Keyword(s):  
Steady State ◽  
Constant Load ◽  
Bicycle Ergometer ◽  
Incremental Exercise ◽  
Maximal Lactate Steady State ◽  
Poincaré Plot ◽  
Incremental Exercise Test ◽  
Load Tests ◽  
Obese Subjects

AbstractThe study assessed if the maximal lactate steady state (MLSS) may be determined by HRV in overweight and obese individuals. Fourteen obese (OB) and 14 overweight (OW) participants performed an incremental exercise test and several constant-load tests on a bicycle ergometer to determine the MLSS. HRV was analysed by using time domain and non-linear parameters of the Poincaré plot. Various HRV thresholds (HRVt) were detected and compared with the MLSS. Overall, Bland-Altman plots demonstrated moderate to strong agreements between the power at the MLSS and the power at HRVt, with all HRVt overestimating the MLSS (range: − 14.6 to−19.8 W). All HRVt were detected at higher intensities (69.2–78.8%Pmax) compared to the MLSS (62.6–66.8%Pmax). The primarily vagally modulated parameter HRVtSD1 revealed higher correlations (r=0.66–0.76) and lower differences (16.8–19.9%) compared to the parameter HRVtSD2 (r=0.56–r=0.66; 22.4–22.9%). The data suggest a delayed vagal withdrawal during incremental exercise in obese and overweight individuals. For this population, the use of HRV to determine the MLSS seems questionable.

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.

scholarly journals Effects of surgical face masks on cardiopulmonary parameters during steady state exercise

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
J. Lässing ◽  
R. Falz ◽  
C. Pökel ◽  
S. Fikenzer ◽  
U. Laufs ◽  
...  
Keyword(s):  
Heart Rate ◽  
Steady State ◽  
Airway Resistance ◽  
Perceived Exertion ◽  
Endurance Performance ◽  
Constant Load ◽  
Rating Of Perceived Exertion ◽  
Lactate Minimum ◽  
Load Tests ◽  
Constant Load Exercise

AbstractWearing face masks reduce the maximum physical performance. Sports and occupational activities are often associated with submaximal constant intensities. This prospective crossover study examined the effects of medical face masks during constant-load exercise. Fourteen healthy men (age 25.7 ± 3.5 years; height 183.8 ± 8.4 cm; weight 83.6 ± 8.4 kg) performed a lactate minimum test and a body plethysmography with and without masks. They were randomly assigned to two constant load tests at maximal lactate steady state with and without masks. The cardiopulmonary and metabolic responses were monitored using impedance cardiography and ergo-spirometry. The airway resistance was two-fold higher with the surgical mask (SM) than without the mask (SM 0.58 ± 0.16 kPa l−1 vs. control [Co] 0.32 ± 0.08 kPa l−1; p < 0.01). The constant load tests with masks compared with those without masks resulted in a significantly different ventilation (77.1 ± 9.3 l min−1 vs. 82.4 ± 10.7 l min−1; p < 0.01), oxygen uptake (33.1 ± 5 ml min−1 kg−1 vs. 34.5 ± 6 ml min−1 kg−1; p = 0.04), and heart rate (160.1 ± 11.2 bpm vs. 154.5 ± 11.4 bpm; p < 0.01). The mean cardiac output tended to be higher with a mask (28.6 ± 3.9 l min−1 vs. 25.9 ± 4.0 l min−1; p = 0.06). Similar blood pressure (177.2 ± 17.6 mmHg vs. 172.3 ± 15.8 mmHg; p = 0.33), delta lactate (4.7 ± 1.5 mmol l−1 vs. 4.3 ± 1.5 mmol l−1; p = 0.15), and rating of perceived exertion (6.9 ± 1.1 vs. 6.6 ± 1.1; p = 0.16) were observed with and without masks. Surgical face masks increase airway resistance and heart rate during steady state exercise in healthy volunteers. The perceived exertion and endurance performance were unchanged. These results may improve the assessment of wearing face masks during work and physical training.

scholarly journals The Effect of 1,3-Butanediol on Cycling Time-Trial Performance

2019 ◽  
Vol 29 (5) ◽  
pp. 466-473 ◽  
Author(s):  
David M. Shaw ◽  
Fabrice Merien ◽  
Andrea Braakhuis ◽  
Daniel Plews ◽  
Paul Laursen ◽  
...  
Keyword(s):  
Steady State ◽  
Body Mass ◽  
Repeated Measures ◽  
Average Power ◽  
Gastrointestinal Symptoms ◽  
Time Trial ◽  
Endurance Performance ◽  
Carbon Dioxide Production ◽  
Serum Glucose ◽  
Cycling Time Trial

This study investigated the effect of the racemic β-hydroxybutyrate (βHB) precursor, R,S-1,3-butanediol (BD), on time-trial (TT) performance and tolerability. A repeated-measures, randomized, crossover study was conducted in nine trained male cyclists (age, 26.7 ± 5.2 years; body mass, 69.6 ± 8.4 kg; height, 1.82 ± 0.09 m; body mass index, 21.2 ± 1.5 kg/m2; VO2peak,63.9 ± 2.5 ml·kg−1·min−1; Wmax, 389.3 ± 50.4 W). Participants ingested 0.35 g/kg of BD or placebo 30 min before and 60 min during 85 min of steady-state exercise, which preceded a ∼25- to 35-min TT (i.e., 7 kJ/kg). The ingestion of BD increased blood D-βHB concentration throughout exercise (0.44–0.79 mmol/L) compared with placebo (0.11–0.16 mmol/L; all p < .001), which peaked 1 hr following the TT (1.38 ± 0.35 vs. 0.34 ± 0.24 mmol/L; p < .001). Serum glucose and blood lactate concentrations were not different between trials (all p > .05). BD ingestion increased oxygen consumption and carbon dioxide production after 20 min of steady-state exercise (p = .002 and p = .032, respectively); however, no further effects on cardiorespiratory parameters were observed. Within the BD trial, moderate to severe gastrointestinal symptoms were reported in five participants, and low levels of dizziness, nausea, and euphoria were reported in two participants. However, this had no effect on TT duration (placebo, 28.5 ± 3.6 min; BD, 28.7 ± 3.2 min; p = .62) and average power output (placebo, 290.1 ± 53.7 W; BD, 286.4 ± 45.9 W; p = .50). These results suggest that BD has no benefit for endurance performance.

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

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.

Functional Threshold Power: Relationship With Respiratory Compensation Point and Effects of Various Warm-Up Protocols

2020 ◽  
Vol 15 (7) ◽  
pp. 1047-1051
Author(s):  
David Barranco-Gil ◽  
Jaime Gil-Cabrera ◽  
Pedro L. Valenzuela ◽  
Lidia B. Alejo ◽  
Almudena Montalvo-Pérez ◽  
...  
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Time Trial ◽  
Maximum Oxygen Uptake ◽  
Compensation Point ◽  
Threshold Power ◽  
Power Relationship ◽  
Warm Up ◽  
Respiratory Compensation Point ◽  
Respiratory Compensation

Purpose: The functional threshold power (FTP), which demarcates the transition from steady state to non-steady-state oxidative metabolism, is usually determined with a 20-minute cycling time trial that follows a standard ∼45-minute warm-up. This study aimed to determine if the standard warm-up inherent to FTP determination is actually necessary and how its modification or removal affects the relationship between FTP and the respiratory compensation point (RCP). Methods: A total of 15 male cyclists (age 35 [9] y, maximum oxygen uptake 66.4 [6.8] mL·kg−1·min−1) participated in this randomized, crossover study. Participants performed a ramp test for determination of RCP and maximum oxygen uptake. During subsequent visits, they performed a 20-minute time trial preceded by the “standard” warm-up that is typically performed before an FTP test (S-WU), a 10-minute warm-up at the power output (PO) corresponding to 60% of maximum oxygen uptake (60%-WU), or no warm-up (No-WU). FTP was computed as 95% of the mean PO attained during the time trial. Results: Although the FTP was correlated with the RCP independently of the warm-up (r = .89, .93, and .86 for No-WU, 60%-WU, and S-WU, respectively; all Ps < .001), the PO at RCP was higher than the FTP in all cases (bias ± 95% limits of agreement = 57 [24], 60 [23], and 57 [32] W for No-WU, 60%-WU, and S-WU, respectively; all Ps < .001 and effect size > 1.70). Conclusions: The FTP is highly correlated with the RCP but corresponds to a significantly lower PO, being these results independent of the warm-up performed (or even with no warm-up).

Is the Functional Threshold Power a Valid Metric to Estimate the Maximal Lactate Steady State in Cyclists?

2019 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
José Ramón Lillo-Beviá ◽  
Javier Courel-Ibáñez ◽  
Victor Cerezuela-Espejo ◽  
Ricardo Morán-Navarro ◽  
Alejandro Martínez-Cava ◽  
...  
Keyword(s):  
Steady State ◽  
Threshold Power ◽  
Maximal Lactate Steady State
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