Effects of Varying the Step Duration on the Determination of Lactate Thresholds in Elite Rowers

2018 ◽  
Vol 13 (6) ◽  
pp. 687-693 ◽  
Author(s):  
Pitre C. Bourdon ◽  
Sarah M. Woolford ◽  
Jonathan D. Buckley

This study aimed to identify the minimum increment duration required to accurately assess 2 distinct lactate thresholds. A total of 21 elite rowers (12 women and 9 men) participated in this study, and each performed 8 or 9 rowing tests comprising 5 progressive incremental tests (3-, 4-, 5-, 7-, or 10-min steps) and at least three 30-min constant-intensity maximal lactate steady-state assessments. Power output (PO) at lactate threshold 1 was higher in the 3- and 4-min incremental tests. No other measures were different for lactate threshold 1. The PO at the second lactate threshold was different between most tests and was higher than the PO at maximal lactate steady state, except for the 10-min incremental test. Lactate threshold 2 oxygen consumption was higher in the 3-, 4-, and 5-min tests, but heart rate (HR) and rating of perceived exertion were not different between tests. Peak PO in the incremental tests was inversely related to the step durations (r2 = .86, P ≤ .02). Peak oxygen consumption was higher in the shorter (≤5 min) than the longer (≥7 min) incremental tests, whereas peak HR was not different between tests. These data suggest that for the methods used in this study, incremental exercise tests with step durations ≤7 min overestimate maximal lactate steady-state exercise intensity, peak physiological values are best determined using incremental tests with step durations ≤4 min, and HR measures are not affected by step duration, and therefore, prescription of training HRs can be made using any of these tests.

1999 ◽  
Vol 9 (4) ◽  
pp. 434-442 ◽  
Author(s):  
Samuel N. Cheuvront ◽  
Robert J. Moffatt ◽  
Kyle D. Biggerstaff ◽  
Shawn Bearden ◽  
Paul McDonough

Claims that ENDUROX™ enhances performance by altering metabolic responses to exercise were tested. In a double-blind crossover design, 10 male subjects were randomly assigned to consume 400 mg of placebo or 800 mg ENDUROX™ for 7 days. Cycle ergometry was performed for 30 minutes at 25%, followed by 10 min at 65% of peak oxygen consumption. After a 1-week washout period, subjects performed the identical exercise protocol following 7 days of reciprocal supplemental conditions. Expired gases were collected and analyzed continuously for oxygen consumption, minute ventilation, and respiratory exchange ratio. Heart rate, blood pressure, rating of perceived exertion, blood lactate, and serum glycerol data were also collected at regular intervals. A two-way ANOVA with repeated measures revealed no significant main or interaction effects involving group differences (p > 0.05) between trials for any variable during rest, 25% or 65% (VO2 peak), or recovery. Our findings do not support the ergogenic claims for ENDUROX™.


2016 ◽  
Vol 122 (1) ◽  
pp. 136-149 ◽  
Author(s):  
Bibiano Madrid ◽  
F.O. Pires ◽  
Jonato Prestes ◽  
Denis César Leite Vieira ◽  
Tyler Clark ◽  
...  

2014 ◽  
Vol 9 (5) ◽  
pp. 772-776 ◽  
Author(s):  
Naiandra Dittrich ◽  
Ricardo Dantas de Lucas ◽  
Ralph Beneke ◽  
Luiz Guilherme Antonacci Guglielmo

The purpose of this study was to determine and compare the time to exhaustion (TE) and the physiological responses at continuous and intermittent (ratio 5:1) maximal lactate steady state (MLSS) in well-trained runners. Ten athletes (32.7 ± 6.9 y, VO2max 61.7 ± 3.9 mL · kg−1 · min−1) performed an incremental treadmill test, three to five 30-min constant-speed tests to determine the MLSS continuous and intermittent (5 min of running, interspaced by 1 min of passive rest), and 2 randomized TE tests at such intensities. Two-way ANOVA with repeated measures was used to compare the changes in physiological variables during the TE tests and between continuous and intermittent exercise. The intermittent MLSS velocity (MLSSint = 15.26 ± 0.97 km/h) was higher than in the continuous model (MLSScon = 14.53 ± 0.93 km/h), while the TE at MLSScon was longer than MLSSint (68 ± 11 min and 58 ± 15 min, P < .05). Regarding the cardiorespiratory responses, VO2 and respiratory-exchange ratio remained stable during both TE tests while heart rate, ventilation, and rating of perceived exertion presented a significant increase in the last portion of the tests. The results showed a higher tolerance to exercising during MLSScon than during MLSSint in trained runners. Thus, the training volume of an extensive interval session (ratio 5:1) designed at MLSS intensity should take into consideration this higher speed at MLSS and also the lower TE than with continuous exercise.


2020 ◽  
Vol 15 (6) ◽  
pp. 853-861
Author(s):  
Claire A. Molinari ◽  
Florent Palacin ◽  
Luc Poinsard ◽  
Véronique L. Billat

Purpose: To validate a new perceptually regulated, self-paced maximal oxygen consumption field test (the Running Advisor Billat Training [RABIT] test) that can be used by recreational runners to define personalized training zones. Design: In a cross-sectional study, male and female recreational runners (N = 12; mean [SD] age = 43 [8] y) completed 3 maximal exercise tests (2 RABIT tests and a University of Montreal Track Test), with a 48-hour interval between tests. Methods: The University of Montreal Track Test was a continuous, incremental track test with a 0.5-km·h−1 increment every minute until exhaustion. The RABIT tests were conducted at intensities of 11, 14, and 17 on the rating of perceived exertion (RPE) scale for 10, 5, and 3 minutes, respectively, with a 1-minute rest between efforts. Results: The 2 RABIT tests and the University of Montreal Track Test gave similar mean (SD) maximal oxygen consumption values (53.9 [6.4], 56.4 [9.1], and 55.4 [7.6] mL·kg−1·min−1, respectively, P = .722). The cardiorespiratory and speed responses were reliable as a function of the running intensity (RPE: 11, 14, and 17) and the relative time point for each RPE stage. Indeed, the oxygen consumption, heart rate, ventilation, and speed values did not differ significantly when the running time was expressed as a relative duration of 30%, 60%, or 90% (ie, at 3, 6, and 9 min of a 10-min effort at RPE 11; P = .997). Conclusions: The results demonstrate that the RABIT test is a valid method for defining submaximal and maximal training zones in recreational runners.


2019 ◽  
Vol 44 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Nicholas Preobrazenski ◽  
Jacob T. Bonafiglia ◽  
Matthew W. Nelms ◽  
Simo Lu ◽  
Lauren Robins ◽  
...  

The purpose of this study was to test the hypotheses (i) that interindividual variability in acute blood lactate responses during exercise at 65% of peak work rate (WRpeak; relative WRpeak protocol (REL)) will predict variability in the chronic responses to exercise training and (ii) that exercising at an intensity that causes uncomfortable speech production (negative talk test (TT) stage (NEG)) elicits high acute blood lactate responses and large adaptations to training. Twenty-eight participants completed 4 weeks of exercise training consisting of REL (n = 14) or NEG (TT, n = 14). Fifteen additional participants were assigned to a no-exercise control group (n = 15). In REL, acute blood lactate responses during the first training session significantly predicted changes in peak oxygen consumption (r = 0.69) after training. TT resulted in consistently high acute blood lactate responses. REL and TT improved (p < 0.05) peak oxygen consumption, WRpeak, and work rate at the onset of blood lactate accumulation (WROBLA). Despite nonsignificance, small to medium between-group effect sizes for changes in peak oxygen consumption, WRpeak, and WROBLA and a higher work rate, heart rate, rating of perceived exertion, and blood lactate during training at NEG support the potential superiority of TT over REL. When exercise is prescribed using a traditional method (a fixed percentage of WRpeak; REL), acute metabolic stress may partly explain the variance in the adaptations to training. In addition, TT elicited significant increases in peak oxygen consumption, WRpeak, and WROBLA, and although our small sample size limits our ability to confidently compare training adaptations between groups, our preliminary results suggest that future investigations with larger sample sizes should assess the potential superiority of TT over REL.


Author(s):  
Claudio Perret ◽  
Kathrin Hartmann

AbstractThe heart rate-based lactate minimum test is a highly reproducible exercise test. However, the relation between lactate minimum determined by this test and maximal lactate steady state in running and cycling is still unclear. Twelve endurance-trained men performed this test in running and cycling. Exercise intensity at maximal lactate steady state was determined by performing several constant heart rate endurance tests for both exercise modes. Heart rate, power output, lactate concentration, oxygen uptake and rating of perceived exertion at lactate minimum, maximal lactate steady state and maximal performance were analysed. All parameters were significantly higher at maximal lactate steady state compared to lactate minimum for running and cycling. Significant correlations (p<0.05) between maximal lactate steady state and lactate minimum data were found. Peak heart rate and peak oxygen uptake were significantly higher for running versus cycling. Nevertheless, the exercise mode had no influence on relative (in percentage of maximal values) heart rate at lactate minimum (p=0.099) in contrast to relative power output (p=0.002). In conclusion, all measured parameters at lactate minimum were significantly lower but highly correlated with values at maximal lactate steady state in running and cycling, which allows to roughly estimate exercise intensity at maximal lactate steady state with one single exercise test.


2015 ◽  
Vol 40 (11) ◽  
pp. 1178-1185 ◽  
Author(s):  
Kristen C. Cochrane ◽  
Terry J. Housh ◽  
Nathaniel D.M. Jenkins ◽  
Haley C. Bergstrom ◽  
Cory M. Smith ◽  
...  

Ten subjects performed four 8-min rides (65%–80% peak oxygen consumption) to determine the physical working capacity at the OMNI rating of perceived exertion (RPE) threshold (PWCOMNI). Polynomial regression analyses were used to examine the patterns of responses for surface electromyographic (EMG) amplitude (EMG AMP), EMG mean power frequency (EMG MPF), mechanomyographic (MMG) AMP, and MMG MPF of the vastus lateralis as well as oxygen consumption rate, respiratory exchange ratio (RER), and power output (PO) were examined during a 1-h ride on a cycle ergometer at a constant RPE that corresponded to the PWCOMNI. EMG AMP and MMG MPF tracked the decreases in oxygen consumption rate, RER, and PO, while EMG MPF and MMG AMP tracked RPE. The decreases in EMG AMP and MMG MPF were likely attributable to decreases in motor unit (MU) recruitment and firing rate, while the lack of change in MMG AMP may have resulted from a balance between MU de-recruitment as PO decreased, and an increase in the ability of activated fibers to oscillate. The current findings suggested that during submaximal cycle ergometry at a constant RPE, MU de-recruitment and mechanical changes within the muscle may influence the perception of effort via feedback from group III and IV afferents.


Author(s):  
Florian Egger ◽  
Dominic Blumenauer ◽  
Patrick Fischer ◽  
Andreas Venhorst ◽  
Saarraaken Kulenthiran ◽  
...  

Abstract Background During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. Methods In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg−1 min−1, maximum performance 5.1 ± 0.5 Watt kg−1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. Results There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). Conclusion Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM.


2010 ◽  
Vol 111 (2) ◽  
pp. 365-378 ◽  
Author(s):  
Herbert Gustavo Simões ◽  
Wolysson Carvalho Hiyane ◽  
Ronaldo Esch Benford ◽  
Bibiano Madrid ◽  
Francisco Andriotti Prada ◽  
...  

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 154 ◽  
Author(s):  
Paul Hafen ◽  
Pat Vehrs

The maximal lactate steady state (MLSS) is one of the factors that differentiates performance in aerobic events. The purpose of this study was to investigate the sex differences in oxygen consumption (VO2), heart rate (HR), and the respiratory exchange ratio (RER) at the MLSS in well-trained distance runners. Twenty-two (12 female, 10 male) well-trained distance runners (23 ± 5.0 years) performed multiple 30-min steady-state runs to determine their MLSS, during which blood lactate and respiratory gas exchange measures were taken. To interpret the MLSS intensity as a training tool, runners completed a time-to-exhaustion (TTE) run at their MLSS. The relative intensity at which the MLSS occurred was identical between males and females according to both oxygen consumption (83 ± 5 %O2max) and heart rate (89 ± 7 %HRmax). However, female runners displayed a significantly lower RER at MLSS compared to male runners (p < 0.0001; 0.84 ± 0.02 vs. 0.88 ± 0.04, respectively). There was not a significant difference in TTE at MLSS between males (79 ± 17 min) and females (80 ± 25 min). Due to the observed difference in the RER at the MLSS, it is suggested that RER derived estimates of MLSS be sex-specific. While the RER data suggest that the MLSS represents different metabolic intensities for males and females, the relative training load of MLSS appears to be similar in males and female runners.


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