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Dotan R. Crystallization of the critical power controversy: response to Black et al. Eur J Appl Physiol 2022; 122:1747-1748. [PMID: 35576082 DOI: 10.1007/s00421-022-04968-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/06/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Raffy Dotan
- Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St Catharines, ON, Canada.
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Keller S, Manunzio C, Wahl P. Comparison of different test protocols to determine maximal lactate steady state intensity in swimming. J Sci Med Sport 2022; 25:696-701. [DOI: 10.1016/j.jsams.2022.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
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Abstract
The elegant concept of a hyperbolic relationship between power, velocity, or torque and time to exhaustion has rightfully captivated the imagination and inspired extensive research for over half a century. Theoretically, the relationship's asymptote along the time axis (critical power, velocity, or torque) indicates the exercise intensity that could be maintained for extended durations, or the "heavy-severe exercise boundary". Much more than a critical mass of the extensive accumulated evidence, however, has persistently shown the determined intensity of critical power and its variants as being too high to maintain for extended periods. The extensive scientific research devoted to the topic has almost exclusively centered around its relationships with various endurance parameters and performances, as well as the identification of procedural problems and how to mitigate them. The prevalent underlying premise has been that the observed discrepancies are mainly due to experimental 'noise' and procedural inconsistencies. Consequently, little or no effort has been directed at other perspectives such as trying to elucidate physiological reasons that possibly underly and account for those discrepancies. This review, therefore, will attempt to offer a new such perspective and point out the discrepancies' likely root causes.
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Affiliation(s)
- Raffy Dotan
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.
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Reverse lactate threshold test accurately predicts maximal lactate steady state and 5 km performance in running. Biol Sport 2021; 38:285-290. [PMID: 34079174 PMCID: PMC8139357 DOI: 10.5114/biolsport.2021.99326] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/04/2020] [Accepted: 09/06/2020] [Indexed: 11/17/2022] Open
Abstract
This study evaluated the accuracy of the reverse lactate threshold (RLT) and the onset of blood lactate accumulation (OBLA; 4 mmol·L-1) to determine the running speed at the maximal lactate steady state (MLSS) and 5 km running performance in a field test approach. Study 1: 16 participants performed an RLT test, and 2 or more constant-speed tests, lasting 30 minutes each, to determine running speed at the MLSS. Study 2: 23 participants performed an RLT test and a 5000 m all-out run as an indicator of performance. The RLT test consisted of an initial lactate-priming segment, in which running speed was increased stepwise up to ~5% above the estimated MLSS, followed by a reverse segment in which speed was decreased by 0.1 m·s-1 every 180 s. RLT was determined using the highest lactate equivalent ([La-]/running speed) during the reverse segment. OBLA was determined during the priming segment and was set at a value of 4 mmol∙L1. The mean difference in MLSS was +0.06 ± 0.05 m·s-1 for RLT, and +0.13 ± 0.23 m·s-1 for OBLA. OBLA showed a good concordance with the MLSS (ICC = 0.83), whereas RLT revealed excellent concordance with the MLSS with an ICC = 0.98. RLT showed a very high correlation with 5000 m speed (r = 0.97). The RLT exhibited exceptional agreement to MLSS and 5000 m running performance. Due to this high accuracy, especially concerning the small intraindividual differences, the RLT test may be superior to common threshold concepts. Further research is needed to evaluate its sensitivity during the training process.
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Decreased Blood Glucose and Lactate: Is a Useful Indicator of Recovery Ability in Athletes? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17155470. [PMID: 32751226 PMCID: PMC7432299 DOI: 10.3390/ijerph17155470] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 12/22/2022]
Abstract
During low-intensity exercise stages of the lactate threshold test, blood lactate concentrations gradually diminish due to the predominant utilization of total fat oxidation. However, it is unclear why blood glucose is also reduced in well-trained athletes who also exhibit decreased lactate concentrations. This review focuses on decreased glucose and lactate concentrations at low-exercise intensity performed in well-trained athletes. During low-intensity exercise, the accrued resting lactate may predominantly be transported via blood from the muscle cell to the liver/kidney. Accordingly, there is increased hepatic blood flow with relatively more hepatic glucose output than skeletal muscle glucose output. Hepatic lactate uptake and lactate output of skeletal muscle during recovery time remained similar which may support a predominant Cori cycle (re-synthesis). However, this pathway may be insufficient to produce the necessary glucose level because of the low concentration of lactate and the large energy source from fat. Furthermore, fatty acid oxidation activates key enzymes and hormonal responses of gluconeogenesis while glycolysis-related enzymes such as pyruvate dehydrogenase are allosterically inhibited. Decreased blood lactate and glucose in low-intensity exercise stages may be an indicator of recovery ability in well-trained athletes. Athletes of intermittent sports may need this recovery ability to successfully perform during competition.
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Wahl P, Manunzio C, Vogt F, Strütt S, Volmary P, Bloch W, Mester J. Accuracy of a Modified Lactate Minimum Test and Reverse Lactate Threshold Test to Determine Maximal Lactate Steady State. J Strength Cond Res 2018; 31:3489-3496. [PMID: 28033123 DOI: 10.1519/jsc.0000000000001770] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Wahl, P, Manunzio, C, Vogt, F, Strütt, S, Volmary, P, Bloch, W, and Mester, J. Accuracy of a modified lactate minimum test and reverse lactate threshold test to determine maximal lactate steady state. J Strength Cond Res 31(12): 3489-3496, 2017-This study evaluated the accuracy of a modified lactate minimum test (mLMT), a modified reverse lactate threshold test (mRLT), compared with 2 established threshold concepts (onset of blood lactate accumulation [OBLA] and modified maximal deviation method [mDmax]) to determine power output at maximal lactate steady state (MLSS) in cycling. Nineteen subjects performed an mLMT, mRLT, graded exercise test (100 W start, +20 W every 3 minutes) and 3 or more constant-load tests of 30 minutes to determine power output at MLSS. The mLMT and mRLT both consisted of an initial lactate priming segment, followed by a short recovery phase. Afterward, the initial load of the subsequent incremental or reverse segment was calculated individually and was increased or decreased by 10 W every 90 seconds, respectively. The mean difference to MLSS was +2 ± 7 W (mLMT), +5 ± 10 W (mRLT), +9 ± 21 W (OBLA), and +6 ± 14 W (mDmax). The correlation between power output at MLSS and mLMT was highest (r = 0.99), followed by mRLT (r = 0.98), mDmax (r = 0.95), and OBLA (r = 0.90). Because of the higher accuracy of the mLMT and the mRLT to determine MLSS compared with OBLA and mDmax, we suggest both tests as valid and meaningful concepts to estimate power output at MLSS in one single test in moderately trained to well-trained athletes. Additionally, our modified tests provide anaerobic data and do not require detailed knowledge of the subjects' training status compared with previous LMT or RLT protocols.
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Affiliation(s)
- Patrick Wahl
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany.,Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany.,The German Research Centre for Elite Sport Cologne, German Sport University Cologne, Cologne, Germany
| | - Christian Manunzio
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| | - Florian Vogt
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| | - Sarah Strütt
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| | - Prisca Volmary
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany.,The German Research Centre for Elite Sport Cologne, German Sport University Cologne, Cologne, Germany
| | - Joachim Mester
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany.,The German Research Centre for Elite Sport Cologne, German Sport University Cologne, Cologne, Germany
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Messias LHD, Polisel EEC, Manchado-Gobatto FB. Advances of the reverse lactate threshold test: Non-invasive proposal based on heart rate and effect of previous cycling experience. PLoS One 2018. [PMID: 29534108 PMCID: PMC5849329 DOI: 10.1371/journal.pone.0194313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Our first aim was to compare the anaerobic threshold (AnT) determined by the incremental protocol with the reverse lactate threshold test (RLT), investigating the previous cycling experience effect. Secondarily, an alternative RLT application based on heart rate was proposed. Two groups (12 per group-according to cycling experience) were evaluated on cycle ergometer. The incremental protocol started at 25 W with increments of 25 W at each 3 minutes, and the AnT was calculated by bissegmentation, onset of blood lactate concentration and maximal deviation methods. The RLT was applied in two phases: a) lactate priming segment; and b) reverse segment; the AnT (AnTRLT) was calculated based on a second order polynomial function. The AnT from the RLT was calculated based on the heart rate (AnTRLT-HR) by the second order polynomial function. In regard of the Study 1, most of statistical procedures converged for similarity between the AnT determined from the bissegmentation method and AnTRLT. For 83% of non-experienced and 75% of experienced subjects the bias was 4% and 2%, respectively. In Study 2, no difference was found between the AnTRLT and AnTRLT-HR. For 83% of non-experienced and 91% of experienced subjects, the bias between AnTRLT and AnTRLT-HR was similar (i.e. 6%). In summary, the AnT determined by the incremental protocol and RLT are consistent. The AnT can be determined during the RLT via heart rate, improving its applicability. However, future studies are required to improve the agreement between variables.
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Messias LHD, Gobatto CA, Beck WR, Manchado-Gobatto FB. The Lactate Minimum Test: Concept, Methodological Aspects and Insights for Future Investigations in Human and Animal Models. Front Physiol 2017. [PMID: 28642717 PMCID: PMC5463055 DOI: 10.3389/fphys.2017.00389] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In 1993, Uwe Tegtbur proposed a useful physiological protocol named the lactate minimum test (LMT). This test consists of three distinct phases. Firstly, subjects must perform high intensity efforts to induce hyperlactatemia (phase 1). Subsequently, 8 min of recovery are allowed for transposition of lactate from myocytes (for instance) to the bloodstream (phase 2). Right after the recovery, subjects are submitted to an incremental test until exhaustion (phase 3). The blood lactate concentration is expected to fall during the first stages of the incremental test and as the intensity increases in subsequent stages, to rise again forming a “U” shaped blood lactate kinetic. The minimum point of this curve, named the lactate minimum intensity (LMI), provides an estimation of the intensity that represents the balance between the appearance and clearance of arterial blood lactate, known as the maximal lactate steady state intensity (iMLSS). Furthermore, in addition to the iMLSS estimation, studies have also determined anaerobic parameters (e.g., peak, mean, and minimum force/power) during phase 1 and also the maximum oxygen consumption in phase 3; therefore, the LMT is considered a robust physiological protocol. Although, encouraging reports have been published in both human and animal models, there are still some controversies regarding three main factors: (1) the influence of methodological aspects on the LMT parameters; (2) LMT effectiveness for monitoring training effects; and (3) the LMI as a valid iMLSS estimator. Therefore, the aim of this review is to provide a balanced discussion between scientific evidence of the aforementioned issues, and insights for future investigations are suggested. In summary, further analyses is necessary to determine whether these factors are worthy, since the LMT is relevant in several contexts of health sciences.
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Affiliation(s)
| | | | - Wladimir R Beck
- Department of Physiological Sciences, Biological and Health Sciences Center, Federal University of São CarlosSão Paulo, Brazil
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Arratibel-Imaz I, Calleja-González J, Emparanza JI, Terrados N, Mjaanes JM, Ostojic SM. Lack of concordance amongst measurements of individual anaerobic threshold and maximal lactate steady state on a cycle ergometer. PHYSICIAN SPORTSMED 2016; 44:34-45. [PMID: 26578151 DOI: 10.1080/00913847.2016.1122501] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION The calculation of exertion intensity, in which a change is produced in the metabolic processes which provide the energy to maintain physical work, has been defined as the anaerobic threshold (AT). The direct calculation of maximal lactate steady state (MLSS) would require exertion intensities over a long period of time and with sufficient rest periods which would prove significantly difficult for daily practice. Many protocols have been used for the indirect calculation of MLSS. OBJECTIVES The aim of this study is to determine if the results of measurements with 12 different AT calculation methods and calculation software [Keul, Simon, Stegmann, Bunc, Dickhuth (TKM and WLa), Dmax, Freiburg, Geiger-Hille, Log-Log, Lactate Minimum] can be used interchangeably, including the method of the fixed threshold of Mader/OBLA's 4 mmol/l and then to compare them with the direct measurement of MLSS. METHODS There were two parts to this research. Phase 1: results from 162 exertion tests chosen at random from the 1560 tests. Phase 2: sixteen athletes (n = 16) carried out different tests on five consecutive days. RESULTS There was very high concordance among all the methods [intraclass correlation coefficient (ICC) > 0.90], except Log-Log in relation to the Stegamnn, Dmax, Dickhuth-WLa and Geiger-Hille. The Dickhuth-TKM showed a high tendency towards concordance, with Dmax (2.2 W) and Dickhuth-WLa (0.1 W). The Dickhuth-TKM method presented a high tendency to concordance with Dickhuth-WLa (0.5 W), Freiburg (7.4 W), MLSS (2.0 W), Bunc (8.9 W), Dmax (0.1 W). The calculation of MLSS power showed a high tendency to concordance, with Dickhuth-TKM (2 W), Dmax (2.1 W), Dickhuth-WLa (1.5 W). CONCLUSION The fixed threshold of 4 mmol/l or OBLA produces slightly different and higher results than those obtained with all the methods analyzed, including MLSS, meaning an overestimation of power in the individual anaerobic threshold. The Dickhuth-TKM, Dmax and Dickhuth-WLa methods defined a high concordance on a cycle ergometer. Dickhuth-TKM, Dmax, Dickhuth-WLa described a high concordance with the power calculated to know the MLSS.
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Affiliation(s)
- Iñaki Arratibel-Imaz
- a Department of Physical Education and Sport , Faculty of Sport Sciences, University of Basque Country , Vitoria-Gasteiz , Spain
| | - Julio Calleja-González
- a Department of Physical Education and Sport , Faculty of Sport Sciences, University of Basque Country , Vitoria-Gasteiz , Spain
| | - Jose Ignacio Emparanza
- b Epidemiology and Public Health, CIBER-ESP, IIS BioDonostia , University Hospital Donostia , Donostia , Spain
| | - Nicolas Terrados
- c Sports Medicine Regional Unit of Asturias-FDM Aviles and Department of Functional Biology , University of Oviedo , Oviedo , Spain
| | - Jeffrey M Mjaanes
- d Regional Department of Orthopedic Surgery and Pediatrics, Midwest Orthopedics at Rush , Rush University Medical Center , Chicago , IL , USA
| | - Sergej M Ostojic
- e Faculty of Sport and Physical Education , University of Novi Sad , Novi Sad , Serbia
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Zagatto AM, Padulo J, Silva ARSD, Müller PDTG, Miyagi WE, Gobatto CA. Physiological responses at the lactate-minimum-intensity with and without prior high-intensity exercise. J Sports Sci 2016; 34:2106-13. [PMID: 26928746 DOI: 10.1080/02640414.2016.1151921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study examined the physiological responses during exercise-to-exhaustion at the lactate-minimum-intensity with and without prior high-intensity exercise. Eleven recreationally trained males performed a graded exercise test, a lactate minimum test and two constant-load tests at lactate-minimum-intensity until exhaustion, which were applied with or without prior hyperlactatemia induction (i.e., 30-s Wingate test). The physiological responses were significantly different (P < 0.05) between constant-load tests for pulmonary ventilation ([Formula: see text]), blood-lactate-concentration ([La(-)]), pH, bicarbonate concentration ([HCO3]) and partial pressure of carbon dioxide during the initial minutes. The comparisons within constant-load tests showed steady state behaviour for oxygen uptake and the respiratory exchange ratio, but heart rate and rating of perceived exertion increased significantly during both exercise conditions, while the [Formula: see text] increased only during constant-load effort. During effort performed after high-intensity exercise: [Formula: see text], [La(-)], pH and [HCO3] differed at the start of exercise compared to another condition but were similar at the end (P > 0.05). In conclusion, the constant-load exercises performed at lactate-minimum-intensity with or without prior high-intensity exercise did not lead to the steady state of all analysed parameters; however, variables such as [La(-)], pH and [HCO3] - altered at the beginning of effort performed after high-intensity exercise - were reestablished after approximately 30 min of exercise.
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Affiliation(s)
| | | | - Adelino Ramos Sanchez da Silva
- c School of Physical Education and Sports of Ribeirão Preto , University of São Paulo (USP) , Ribeirão Preto , SP , Brazil
| | - Paulo de Tarso Guerrero Müller
- d Laboratory of Respiratory Pathophysiology (LAFIR), Federal University of Mato Grosso do Sul (UFMS) , Campo Grande , MS , Brazil
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Critical power: what is being measured and why? Eur J Appl Physiol 2014; 114:2677-8. [DOI: 10.1007/s00421-014-2961-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 07/16/2014] [Indexed: 10/25/2022]
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