8,153
edits
Changes
From Fellrnr.com, Running tips
Created page with "Introduction pending. =What is Lactate?= ''Main article: Lactate'' At one time Lactate was viewed as a harmful waste product due anaerobic exercise, but research sin..."
Introduction pending.
=What is Lactate?=
''Main article: [[Lactate]]''
At one time [[Lactate]] was viewed as a harmful waste product due anaerobic exercise, but research since the early 2000s has shown that Lactate is an intermediate fuel in the metabolism of carbohydrates. Muscles will burn Lactate in preference to Glucose, and will convert Lactate back to Glucose at rest. The level of Lactate in the blood is primarily dependent on exercise intensity. Note that Lactate forms Lactic Acid in the blood, and the terms are used interchangeably. Lactate is used as a fuel source by working muscles, and injecting extra lactate into the blood results in increased lactate metabolism and carbohydrate sparing<ref name="MillerFattor2002"/> without impairing performance<ref name="EllisSimmons2009"/>.
=What is the Lactate Threshold?=
The Lactate Threshold (LT) is the point at which the lactate level in the blood will rise even if the work intensity is kept constant. This is sometimes referred to as the Anaerobic Threshold (AT), or the Onset of Blood Lactate Accumulation (OBLA), though the most accurate term is Maximal Lactate Steady State (MLSS). Even within the scientific community terminology is confusing<ref name="Binder-2008"/>. It is sometimes believed that the MLSS represents the maximum clearance of Lactate, but this may not be the case<ref name="EllisSimmons2009"/>. Note that Lactate is normally measured in the blood stream, so the Lactate level reflects the net of the muscles releasing and absorbing Lactate.
Lactate Threshold is important as it is an excellent good predictor of race performance<ref name="Billat-1996"/><ref name="Palmer-1999"/><ref name="Baldari-2000"/><ref name="Jones-2000"/>. Lactate Threshold can be thought of as the percentage of VO2max that can be maintained for a protracted time<ref name="Costill-1973"/>, though it's not clear what the limiting factor is for exercise above the Lactate Threshold<ref name="Baron-2008"/>.
=Lactate Curve=
It is common to plot exercise intensity against lactate level to produce a blood lactate curve similar to the one below, showing an exponential rise in lactate level with intensity. It's generally accepted that a shift of the curve to the right indicates an improved athletic performance<ref name="Bosquet-2002"/><ref name="Yoshida-1990"/>, and training can improve performance because of this shift without a change in aerobic capacity ([[VO2max|V̇O<sub>2</sub>max]])<ref name="Acevedo-1989"/>. There is some limited evidence from radio-isotope studies in animals that a benefit of endurance training may be in Lactate clearance<ref name="Donovan-1983"/>. Note that above the Lactate Threshold the Lactate level is not at a steady state, but rises even though the intensity remains constant, so the typical curve that is shown is rather misleading.
[[File:Blood Lactate Curve.jpg|none|thumb|500px|A typically blood lactate curve with lactate level plotted against intensity.]]
=Lactate Threshold Training =
''Main article: [[Tempo Runs]]''
There is good evidence that endurance training changes Lactate Threshold. However, the idea that training at threshold intensity (Tempo Runs) is particularly effective has no evidence<ref name="Beneke-2011"/>"/><ref name="Guellich-2010"/>, and polarized training is a better approach<ref name="StögglSperlich2014"/><ref name="Muñoz-2014"/>. For trained athletes, Tempo runs are ineffective<ref name="Londeree-1997"/> and may actually be counterproductive<ref name="Evertsen-2001"/><ref name="Guellich-2010"/>. See [[Tempo Runs]] for more details.
Detraining shifts the curve to the left<ref name="Coyle-1985"/>. Lactate levels can be higher at a given intensity after just a few days without training<ref name="Mujika-2001"/>, suggesting rapid detraining effects.
=Determining Lactate Threshold=
There are various ways of determining the Lactate Threshold, each with their own problems.
* '''MLSS'''. The gold standard test (and the only one that appears to be valid) is to measure Maximal Lactate Steady State (MLSS). The test requires 3 to 5 constant intensity trials of at least 30 minutes' duration, each performed on separate days. Each test is at a different exercise intensity, and the highest intensity that does not have a rise in blood lactate in the last 20 minutes is the MLSS. While this is the best way of determining Lactate threshold, it's obviously time consuming and interferes with the athlete's regular training. Because of the effort of MLSS testing, various shortcuts have been tried.
* '''Fixed Blood Lactate Accumulation'''. A simple approach is to assume that Lactate Threshold always occurs at the same Lactate level. Sadly, this assumption is wrong, as Lactate Threshold can occur at vastly different levels.
* '''Lactate Patterns'''. There are various approaches that look at the pattern of change in Lactate in an attempt to create a simple test. So far, I've seen little evidence to support any of these approaches.
* '''Heart Rate Deflection'''. An indirect way of finding Lactate Threshold is to look for the [[Heart Rate Deflection]], sometimes called the "Conconi test". This test only requires a heart rate monitor to perform rather than blood draws, so it is much easier than the above approaches. However, the validity of the Conconi test has many issues and seems of dubious value<ref name="Cook2011"/>. See [[Heart Rate Deflection]] for details.
* '''Respiratory gasses'''. Another method for estimating Lactate Threshold is to measure the respiratory gasses<ref name="Binder-2008"/><ref name="Laplaud-2006"/>, but given this is impractical for most athletes, it's not covered here.
==Lactate Threshold & Maximal Lactate Steady State ==
The best approach to determine Lactate Threshold is to measure the Maximal Lactate Steady State (MLSS)<ref name="Faude-2009"/>. The test is actually several constant load trials of at least 30 minutes' duration on different days at various exercise intensities (in the range of 50–90% [[VO2max|V̇O<sub>2</sub>max]]. The highest workload that results in an increase of less than 1 mmol/L of lactate between the 10 and 30 minute mark defines the MLSS<ref name="Urhausen-1993"/><ref name="De SouzaGrossl2012"/><ref name="Beneke-2003"/>. Lactate is typically measured using a blood sample, either using a pinprick or a catheter. Note that MLSS for a given individual will vary by sport<ref name="Figueira-2008"/>, probably based on the mass of muscle engaged<ref name="Beneke-1996"/><ref name="Beneke-2003-2"/>. The difficulty of performing this test makes it impractical in most situations.
[[File:LactateMLSS.jpg|none|thumb|500px|Blood lactate levels over time at various workloads. The lower lines are at lower intensities, with the line marked MLSS being the highest intensity that produces stable lactate levels.]]
==Lactate Threshold & Incremental Power Test ==
A common approach to determine the Lactate Threshold is the Incremental Power Test. The subject exercises in stages of increasing intensity, with lactate measured at the end of each stage, with stages typically lasting 3 to 10 minutes. However, blood lactate takes 20-30 minutes to stabilize for a given intensity<ref name="Billat-1996"/>. This means that the incremental power test tends to be of limited value<ref name="Foxdal-1996"/>, with 3 minute stages giving low reproducibility<ref name="Morton-2012"/>, the stage length changing the lactate values<ref name="Faude-2009"/>, and even longer stages lengths of 8 minutes having low reproducibility<ref name="Gavin-2014"/>. The lactate level can drop between the 4<sup>th</sup> and 12<sup>th</sup> minute of exercise at a constant intensity<ref name="RieuMiladi1989"/>. Some have suggested using the lactate value measured as an indication of the prior stage's intensity, as it takes more than 3 minutes for lactate to stabilize<ref name="Orok-1989"/>, but this rather arbitrary approach can be used as a guideline (at best)<ref name="Baldari-2000"/>. For running, it is common to pause the exercise for 30 seconds to take a blood sample. These breaks only make a non-significant difference to the testing, though the slight difference tends to be greater at higher intensities<ref name="GullstrandSjüdin2007"/>.
==Lactate Threshold & Fixed Blood Lactate Accumulation==
Because MLSS is time consuming and expensive, a shortcut is often used to estimate MLSS by assuming that it occurs at a fixed Lactate Level (Fixed Blood Lactate Accumulation, or FBLA)<ref name="De SouzaGrossl2012"/>, unusually 4.0 mmol/l<ref name="Heck-1985"/> though sometimes 3.5 mmol/l<ref name="DenadaiFigueira2004"/><ref name="Denadai-2005"/>. However, while the MLSS may average around 4.0 mmol/l<ref name="Denadai-2005"/>, there are significant differences for individuals<ref name="Mamen-2009"/>, with variations between 3.0 and 5.5 in small sample sizes<ref name="Heck-1985"/> and has been shown to have a range as wide as 2.0 to 10.0 mmol/l<ref name="Faude-2009"/><ref name="Stegmann-1981"/>. This approach also typically uses a blood test, but in some sports (like running), the athlete has to pause to have a pinprick blood sample taken, further confusing the test<ref name="Heck-1985"/>. The term "Individual Anaerobic Threshold" (IAT) has been used to emphasize that the Lactate Threshold is specific to each individual rather than using a FBLA, though this can refer to a specific protocol for estimating MLSS<ref name="Stegmann-1981"/>. The Fixed Blood Lactate Accumulation is sometimes called "Onset of Blood Lactate Accumulation" (OBLA)<ref name="Mamen-2009"/>, a particularly misleading term in this context.
==Lactate Threshold Estimation From Lactate Patterns==
There have been several approaches to determining MLSS without the difficulty of the full protocol<ref name="Billat-1994"/><ref name="Harnish-2001"/><ref name="Palmer-1999"/><ref name="Tegtbur-1993"/><ref name="Dickhuth-1999"/><ref name="Urhausen-1993"/>, but their validity is limited<ref name="Kilding-2005"/><ref name="De SouzaGrossl2012"/><ref name="Beneke-1995"/>. These approaches generally look for some pattern in the change of Lactate level.
For example, one approach called the "Lactate Minimum Speed Test" (LMST) uses an initial sprint to elevate blood lactate followed by an incremental power test<ref name="SoteroPardono2009"/><ref name="Sotero-2009"/><ref name="MiyagiLeite2013"/>. However, the effectiveness of the LMST is profoundly impacted by the starting speed of the incremental portion of the test<ref name="Carter-1999"/>and so the results may be coincidence<ref name="Carter-2000"/>. This is not entirely surprising given the initial sprint phase disrupts the metabolism<ref name="Carter-2000"/>.
Part of the problem with these approaches may be that MLSS may not represent the point of maximum lactate clearance<ref name="Beneke-2003-2"/>, as injecting additional lactate into the blood of athletes exercising above MLSS did not significantly increase lactate levels<ref name="EllisSimmons2009"/>.
Some of the tests could be "p-hacking", where the study looks at a sufficiently large number of variables that some correlation occurs randomly<ref name="HeadHolman2015"/>.
[[File:LactateComp.jpg|none|thumb|500px|The correlation (or lack thereof) between MLSS and the lactate levels at the MLSS intensity seen during 3 or 5 minute incremental power tests<ref name="Heck-1985"/>.]]
=Factors that may influence Lactate Threshold=
There are a few factors that may change the Lactate Threshold (other than training)
* Because lactate is produced from the metabolism of carbohydrate, a reduction in carbohydrate intake (or [[Glycogen]] depletion) will shift the lactate curve to the right<ref name="Reilly-1999"/><ref name="Yoshida-1984"/><ref name="Maassen-1989"/><ref name="McLellan-1989"/>.
* It's not clear if [[Delayed Onset Muscle Soreness]] changes the lactate curve as there are reports that it does<ref name="Gleeson-1998"/> and reports that it does not<ref name="Davies-2011"/>.
* Lactate Threshold will vary by sport, probably based on the mass of muscle engaged<ref name="Beneke-1996"/>, or because the inactive muscles consume more lactate as the concentration rises<ref name="Orok-1989"/>. MLSS may also vary with environmental conditions, with a lower lactate levels at MLSS in hotter conditions<ref name="de Barros-2011"/>.
=Aerobic Threshold=
There is a related concept called "Aerobic Threshold" that is generally used to mean the exercise intensity at which Lactate levels rise above resting baselines<ref name="Faude-2009"/>. This threshold is believed to be the upper limit of nearly exclusive use of aerobic metabolism that can be sustained for many hours. Intensities just above the aerobic threshold can be maintained for prolonged periods (~4 hours)<ref name="Meyer-2003"/>. This aerobic threshold can be hard to determine in untrained subjects as it occurs at very low intensities<ref name="Seiler-2010"/>. Unfortunately, the term "Lactate Threshold" is sometimes used to mean this point where lactate rises above resting levels<ref name="Yoshida-1984"/>.
=References=
<references>
<ref name="Cook2011">I Cook, Was the Conconi test validated by sporting success, expert opinion or good science?, South African Journal for Research in Sport, Physical Education and Recreation, volume 33, issue 1, 2011, ISSN [http://www.worldcat.org/issn/0379-9069 0379-9069], doi [http://dx.doi.org/10.4314/sajrs.v33i1.65483 10.4314/sajrs.v33i1.65483]</ref>
<ref name="Beneke-1996">R. Beneke, SP. von Duvillard, Determination of maximal lactate steady state response in selected sports events., Med Sci Sports Exerc, volume 28, issue 2, pages 241-6, Feb 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8775160 8775160]</ref>
<ref name="Stegmann-1981">H. Stegmann, W. Kindermann, A. Schnabel, Lactate kinetics and individual anaerobic threshold., Int J Sports Med, volume 2, issue 3, pages 160-5, Aug 1981, doi [http://dx.doi.org/10.1055/s-2008-1034604 10.1055/s-2008-1034604], PMID [http://www.ncbi.nlm.nih.gov/pubmed/7333753 7333753]</ref>
<ref name="Heck-1985">H. Heck, A. Mader, G. Hess, S. Mücke, R. Müller, W. Hollmann, Justification of the 4-mmol/l lactate threshold., Int J Sports Med, volume 6, issue 3, pages 117-30, Jun 1985, doi [http://dx.doi.org/10.1055/s-2008-1025824 10.1055/s-2008-1025824], PMID [http://www.ncbi.nlm.nih.gov/pubmed/4030186 4030186]</ref>
<ref name="Faude-2009">O. Faude, W. Kindermann, T. Meyer, Lactate threshold concepts: how valid are they?, Sports Med, volume 39, issue 6, pages 469-90, 2009, PMID [http://www.ncbi.nlm.nih.gov/pubmed/19453206 19453206]</ref>
<ref name="De SouzaGrossl2012">Kristopher Mendes De Souza, Talita Grossl, Rubens José Babel Junior, Ricardo Dantas De Lucas, Vitor Pereira Costa, Luiz Guilherme Antonacci Guglielmo, Máximo estado estável de lactato estimado por diferentes métodos de determinação, Revista Brasileira de Cineantropometria e Desempenho Humano, volume 14, issue 3, 2012, ISSN [http://www.worldcat.org/issn/1980-0037 1980-0037], doi [http://dx.doi.org/10.5007/1980-0037.2012v14n3p264 10.5007/1980-0037.2012v14n3p264]</ref>
<ref name="Urhausen-1993">A. Urhausen, B. Coen, B. Weiler, W. Kindermann, Individual anaerobic threshold and maximum lactate steady state., Int J Sports Med, volume 14, issue 3, pages 134-9, Apr 1993, doi [http://dx.doi.org/10.1055/s-2007-1021157 10.1055/s-2007-1021157], PMID [http://www.ncbi.nlm.nih.gov/pubmed/8509241 8509241]</ref>
<ref name="Costill-1973">DL. Costill, H. Thomason, E. Roberts, Fractional utilization of the aerobic capacity during distance running., Med Sci Sports, volume 5, issue 4, pages 248-52, 1973, PMID [http://www.ncbi.nlm.nih.gov/pubmed/4774203 4774203]</ref>
<ref name="McLellan-1989">TM. McLellan, GC. Gass, The relationship between the ventilation and lactate thresholds following normal, low and high carbohydrate diets., Eur J Appl Physiol Occup Physiol, volume 58, issue 6, pages 568-76, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2731528 2731528]</ref>
<ref name="Maassen-1989">N. Maassen, MW. Busse, The relationship between lactic acid and work load: a measure for endurance capacity or an indicator of carbohydrate deficiency?, Eur J Appl Physiol Occup Physiol, volume 58, issue 7, pages 728-37, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2737193 2737193]</ref>
<ref name="Yoshida-1984">T. Yoshida, Effect of dietary modifications on lactate threshold and onset of blood lactate accumulation during incremental exercise., Eur J Appl Physiol Occup Physiol, volume 53, issue 3, pages 200-5, 1984, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6542853 6542853]</ref>
<ref name="Reilly-1999">T. Reilly, V. Woodbridge, Effects of moderate dietary manipulations on swim performance and on blood lactate-swimming velocity curves., Int J Sports Med, volume 20, issue 2, pages 93-7, Feb 1999, doi [http://dx.doi.org/10.1055/s-2007-971099 10.1055/s-2007-971099], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10190768 10190768]</ref>
<ref name="Coyle-1985">EF. Coyle, WH. Martin, SA. Bloomfield, OH. Lowry, JO. Holloszy, Effects of detraining on responses to submaximal exercise., J Appl Physiol (1985), volume 59, issue 3, pages 853-9, Sep 1985, PMID [http://www.ncbi.nlm.nih.gov/pubmed/3902770 3902770]</ref>
<ref name="Yoshida-1990">T. Yoshida, M. Udo, M. Chida, M. Ichioka, K. Makiguchi, T. Yamaguchi, Specificity of physiological adaptation to endurance training in distance runners and competitive walkers., Eur J Appl Physiol Occup Physiol, volume 61, issue 3-4, pages 197-201, 1990, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2282901 2282901]</ref>
<ref name="Acevedo-1989">EO. Acevedo, AH. Goldfarb, Increased training intensity effects on plasma lactate, ventilatory threshold, and endurance., Med Sci Sports Exerc, volume 21, issue 5, pages 563-8, Oct 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2607946 2607946]</ref>
<ref name="Bosquet-2002">L. Bosquet, L. Léger, P. Legros, Methods to determine aerobic endurance., Sports Med, volume 32, issue 11, pages 675-700, 2002, PMID [http://www.ncbi.nlm.nih.gov/pubmed/12196030 12196030]</ref>
<ref name="Beneke-2011">R. Beneke, RM. Leithäuser, O. Ochentel, Blood lactate diagnostics in exercise testing and training., Int J Sports Physiol Perform, volume 6, issue 1, pages 8-24, Mar 2011, PMID [http://www.ncbi.nlm.nih.gov/pubmed/21487146 21487146]</ref>
<ref name="Billat-1994">V. Billat, F. Dalmay, MT. Antonini, AP. Chassain, A method for determining the maximal steady state of blood lactate concentration from two levels of submaximal exercise., Eur J Appl Physiol Occup Physiol, volume 69, issue 3, pages 196-202, 1994, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8001529 8001529]</ref>
<ref name="Kilding-2005">AE. Kilding, AM. Jones, Validity of a single-visit protocol to estimate the maximum lactate steady state., Med Sci Sports Exerc, volume 37, issue 10, pages 1734-40, Oct 2005, PMID [http://www.ncbi.nlm.nih.gov/pubmed/16260974 16260974]</ref>
<ref name="Harnish-2001">CR. Harnish, TC. Swensen, RR. Pate, Methods for estimating the maximal lactate steady state in trained cyclists., Med Sci Sports Exerc, volume 33, issue 6, pages 1052-5, Jun 2001, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11404673 11404673]</ref>
<ref name="Palmer-1999">AS. Palmer, JA. Potteiger, KL. Nau, RJ. Tong, A 1-day maximal lactate steady-state assessment protocol for trained runners., Med Sci Sports Exerc, volume 31, issue 9, pages 1336-41, Sep 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10487377 10487377]</ref>
<ref name="Tegtbur-1993">U. Tegtbur, MW. Busse, KM. Braumann, Estimation of an individual equilibrium between lactate production and catabolism during exercise., Med Sci Sports Exerc, volume 25, issue 5, pages 620-7, May 1993, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8492691 8492691]</ref>
<ref name="Beneke-2003">R. Beneke, Methodological aspects of maximal lactate steady state-implications for performance testing., Eur J Appl Physiol, volume 89, issue 1, pages 95-9, Mar 2003, doi [http://dx.doi.org/10.1007/s00421-002-0783-1 10.1007/s00421-002-0783-1], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12627312 12627312]</ref>
<ref name="Stegmann-1981">H. Stegmann, W. Kindermann, A. Schnabel, Lactate kinetics and individual anaerobic threshold., Int J Sports Med, volume 2, issue 3, pages 160-5, Aug 1981, doi [http://dx.doi.org/10.1055/s-2008-1034604 10.1055/s-2008-1034604], PMID [http://www.ncbi.nlm.nih.gov/pubmed/7333753 7333753]</ref>
<ref name="Orok-1989">CJ. Orok, RL. Hughson, HJ. Green, JA. Thomson, Blood lactate responses in incremental exercise as predictors of constant load performance., Eur J Appl Physiol Occup Physiol, volume 59, issue 4, pages 262-7, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2583172 2583172]</ref>
<ref name="Binder-2008">RK. Binder, M. Wonisch, U. Corra, A. Cohen-Solal, L. Vanhees, H. Saner, JP. Schmid, Methodological approach to the first and second lactate threshold in incremental cardiopulmonary exercise testing., Eur J Cardiovasc Prev Rehabil, volume 15, issue 6, pages 726-34, Dec 2008, doi [http://dx.doi.org/10.1097/HJR.0b013e328304fed4 10.1097/HJR.0b013e328304fed4], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19050438 19050438]</ref>
<ref name="Gavin-2014">JP. Gavin, ME. Willems, SD. Myers, Reproducibility of lactate markers during 4 and 8 min stage incremental running: a pilot study., J Sci Med Sport, volume 17, issue 6, pages 635-9, Nov 2014, doi [http://dx.doi.org/10.1016/j.jsams.2013.08.006 10.1016/j.jsams.2013.08.006], PMID [http://www.ncbi.nlm.nih.gov/pubmed/24028777 24028777]</ref>
<ref name="Morton-2012">RH. Morton, SR. Stannard, B. Kay, Low reproducibility of many lactate markers during incremental cycle exercise., Br J Sports Med, volume 46, issue 1, pages 64-9, Jan 2012, doi [http://dx.doi.org/10.1136/bjsm.2010.076380 10.1136/bjsm.2010.076380], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21343140 21343140]</ref>
<ref name="Dickhuth-1999">HH. Dickhuth, L. Yin, A. Niess, K. Röcker, F. Mayer, HC. Heitkamp, T. Horstmann, Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility., Int J Sports Med, volume 20, issue 2, pages 122-7, Feb 1999, doi [http://dx.doi.org/10.1055/s-2007-971105 10.1055/s-2007-971105], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10190774 10190774]</ref>
<ref name="Meyer-2003">T. Meyer, HH. Gabriel, M. Auracher, J. Scharhag, W. Kindermann, Metabolic profile of 4 h cycling in the field with varying amounts of carbohydrate supply., Eur J Appl Physiol, volume 88, issue 4-5, pages 431-7, Jan 2003, doi [http://dx.doi.org/10.1007/s00421-002-0712-3 10.1007/s00421-002-0712-3], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12527974 12527974]</ref>
<ref name="Billat-1996">LV. Billat, Use of blood lactate measurements for prediction of exercise performance and for control of training. Recommendations for long-distance running., Sports Med, volume 22, issue 3, pages 157-75, Sep 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8883213 8883213]</ref>
<ref name="EllisSimmons2009">Darren Ellis, Catherine Simmons, Benjamin F. Miller, Sodium lactate infusion during a cycling time-trial does not increase lactate concentration or decrease performance, European Journal of Sport Science, volume 9, issue 6, 2009, pages 367–374, ISSN [http://www.worldcat.org/issn/1746-1391 1746-1391], doi [http://dx.doi.org/10.1080/17461390903009158 10.1080/17461390903009158]</ref>
<ref name="MillerFattor2002">Benjamin F. Miller, Jill A. Fattor, Kevin A. Jacobs, Michael A. Horning, Franco Navazio, Michael I. Lindinger, George A. Brooks, Lactate and glucose interactions during rest and exercise in men: effect of exogenous lactate infusion, The Journal of Physiology, volume 544, issue 3, 2002, pages 963–975, ISSN [http://www.worldcat.org/issn/00223751 00223751], doi [http://dx.doi.org/10.1113/jphysiol.2002.027128 10.1113/jphysiol.2002.027128]</ref>
<ref name="Figueira-2008">TR. Figueira, F. Caputo, JG. Pelarigo, BS. Denadai, Influence of exercise mode and maximal lactate-steady-state concentration on the validity of OBLA to predict maximal lactate-steady-state in active individuals., J Sci Med Sport, volume 11, issue 3, pages 280-6, Jun 2008, doi [http://dx.doi.org/10.1016/j.jsams.2007.02.016 10.1016/j.jsams.2007.02.016], PMID [http://www.ncbi.nlm.nih.gov/pubmed/17553745 17553745]</ref>
<ref name="DenadaiFigueira2004">B.S. Denadai, T.R. Figueira, O.R.P. Favaro, M. Gonçalves, Effect of the aerobic capacity on the validity of the anaerobic threshold for determination of the maximal lactate steady state in cycling, Brazilian Journal of Medical and Biological Research, volume 37, issue 10, 2004, pages 1551–1556, ISSN [http://www.worldcat.org/issn/1678-4510 1678-4510], doi [http://dx.doi.org/10.1590/S0100-879X2004001000015 10.1590/S0100-879X2004001000015]</ref>
<ref name="Denadai-2005">BS. Denadai, EB. Gomide, CC. Greco, The relationship between onset of blood lactate accumulation, critical velocity, and maximal lactate steady state in soccer players., J Strength Cond Res, volume 19, issue 2, pages 364-8, May 2005, doi [http://dx.doi.org/10.1519/1533-4287(2005)19[364:TRBOOB]2.0.CO;2 10.1519/1533-4287(2005)19[364:TRBOOB]2.0.CO;2], PMID [http://www.ncbi.nlm.nih.gov/pubmed/15903376 15903376]</ref>
<ref name="Baron-2008">B. Baron, TD. Noakes, J. Dekerle, F. Moullan, S. Robin, R. Matran, P. Pelayo, Why does exercise terminate at the maximal lactate steady state intensity?, Br J Sports Med, volume 42, issue 10, pages 828-33, Oct 2008, doi [http://dx.doi.org/10.1136/bjsm.2007.040444 10.1136/bjsm.2007.040444], PMID [http://www.ncbi.nlm.nih.gov/pubmed/18070803 18070803]</ref>
<ref name="Laplaud-2006">D. Laplaud, M. Guinot, A. Favre-Juvin, P. Flore, Maximal lactate steady state determination with a single incremental test exercise., Eur J Appl Physiol, volume 96, issue 4, pages 446-52, Mar 2006, doi [http://dx.doi.org/10.1007/s00421-005-0086-4 10.1007/s00421-005-0086-4], PMID [http://www.ncbi.nlm.nih.gov/pubmed/16341873 16341873]</ref>
<ref name="Beneke-2003-2">R. Beneke, Maximal lactate steady state concentration (MLSS): experimental and modelling approaches., Eur J Appl Physiol, volume 88, issue 4-5, pages 361-9, Jan 2003, doi [http://dx.doi.org/10.1007/s00421-002-0713-2 10.1007/s00421-002-0713-2], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12527964 12527964]</ref>
<ref name="Sotero-2009">RC. Sotero, E. Pardono, R. Landwehr, CS. Campbell, HG. Simoes, Blood glucose minimum predicts maximal lactate steady state on running., Int J Sports Med, volume 30, issue 9, pages 643-6, Sep 2009, doi [http://dx.doi.org/10.1055/s-0029-1220729 10.1055/s-0029-1220729], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19569005 19569005]</ref>
<ref name="de Barros-2011">CL. de Barros, TT. Mendes, LÁ. Mortimer, HG. Simões, LS. Prado, U. Wisloff, E. Silami-Garcia, Maximal lactate steady state is altered in the heat., Int J Sports Med, volume 32, issue 10, pages 749-53, Oct 2011, doi [http://dx.doi.org/10.1055/s-0031-1277191 10.1055/s-0031-1277191], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21590640 21590640]</ref>
<ref name="SoteroPardono2009">Rafael da Costa Sotero, Emerson Pardono, Carmen Sílvia Grubert Campbell, Herbert Gustavo Simões, Indirect Assessment of Lactate Minimum and Maximal Blood Lactate Steady-State Intensity for Physically Active Individuals, Journal of Strength and Conditioning Research, volume 23, issue 3, 2009, pages 847–853, ISSN [http://www.worldcat.org/issn/1064-8011 1064-8011], doi [http://dx.doi.org/10.1519/JSC.0b013e318196b609 10.1519/JSC.0b013e318196b609]</ref>
<ref name="Guellich-2010">A. Guellich, S. Seiler, Lactate profile changes in relation to training characteristics in junior elite cyclists., Int J Sports Physiol Perform, volume 5, issue 3, pages 316-27, Sep 2010, PMID [http://www.ncbi.nlm.nih.gov/pubmed/20861522 20861522]</ref>
<ref name="Seiler-2010">S. Seiler, What is best practice for training intensity and duration distribution in endurance athletes?, Int J Sports Physiol Perform, volume 5, issue 3, pages 276-91, Sep 2010, PMID [http://www.ncbi.nlm.nih.gov/pubmed/20861519 20861519]</ref>
<ref name="StögglSperlich2014">Thomas Stöggl, Billy Sperlich, Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training, Frontiers in Physiology, volume 5, 2014, ISSN [http://www.worldcat.org/issn/1664-042X 1664-042X], doi [http://dx.doi.org/10.3389/fphys.2014.00033 10.3389/fphys.2014.00033]</ref>
<ref name="Londeree-1997">BR. Londeree, Effect of training on lactate/ventilatory thresholds: a meta-analysis., Med Sci Sports Exerc, volume 29, issue 6, pages 837-43, Jun 1997, PMID [http://www.ncbi.nlm.nih.gov/pubmed/9219214 9219214]</ref>
<ref name="Evertsen-2001">F. Evertsen, JI. Medbø, A. Bonen, Effect of training intensity on muscle lactate transporters and lactate threshold of cross-country skiers., Acta Physiol Scand, volume 173, issue 2, pages 195-205, Oct 2001, doi [http://dx.doi.org/10.1046/j.1365-201X.2001.00871.x 10.1046/j.1365-201X.2001.00871.x], PMID [http://www.ncbi.nlm.nih.gov/pubmed/11683677 11683677]</ref>
<ref name="Baldari-2000">C. Baldari, L. Guidetti, A simple method for individual anaerobic threshold as predictor of max lactate steady state., Med Sci Sports Exerc, volume 32, issue 10, pages 1798-802, Oct 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11039656 11039656]</ref>
<ref name="Muñoz-2014">I. Muñoz, S. Seiler, J. Bautista, J. España, E. Larumbe, J. Esteve-Lanao, Does polarized training improve performance in recreational runners?, Int J Sports Physiol Perform, volume 9, issue 2, pages 265-72, Mar 2014, doi [http://dx.doi.org/10.1123/ijspp.2012-0350 10.1123/ijspp.2012-0350], PMID [http://www.ncbi.nlm.nih.gov/pubmed/23752040 23752040]</ref>
<ref name="Beneke-1995">R. Beneke, Anaerobic threshold, individual anaerobic threshold, and maximal lactate steady state in rowing., Med Sci Sports Exerc, volume 27, issue 6, pages 863-7, Jun 1995, PMID [http://www.ncbi.nlm.nih.gov/pubmed/7658947 7658947]</ref>
<ref name="RieuMiladi1989">M. Rieu, J. Miladi, A. Ferry, A. Duvallet, Blood lactate during submaximal exercises, European Journal of Applied Physiology and Occupational Physiology, volume 59, issue 1-2, 1989, pages 73–79, ISSN [http://www.worldcat.org/issn/0301-5548 0301-5548], doi [http://dx.doi.org/10.1007/BF02396583 10.1007/BF02396583]</ref>
<ref name="Mujika-2001">I. Mujika, S. Padilla, Cardiorespiratory and metabolic characteristics of detraining in humans., Med Sci Sports Exerc, volume 33, issue 3, pages 413-21, Mar 2001, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11252068 11252068]</ref>
<ref name="GullstrandSjüdin2007">L. Gullstrand, B. Sjüdin, J. Svedenhag, Blood sampling during continuous running and 30-second intervals on a treadmill, Scandinavian Journal of Medicine & Science in Sports, volume 4, issue 4, 2007, pages 239–242, ISSN [http://www.worldcat.org/issn/09057188 09057188], doi [http://dx.doi.org/10.1111/j.1600-0838.1994.tb00434.x 10.1111/j.1600-0838.1994.tb00434.x]</ref>
<ref name="Carter-1999">H. Carter, AM. Jones, JH. Doust, Effect of incremental test protocol on the lactate minimum speed., Med Sci Sports Exerc, volume 31, issue 6, pages 837-45, Jun 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10378911 10378911]</ref>
<ref name="Carter-2000">H. Carter, AM. Jones, JH. Doust, Changes in blood lactate and pyruvate concentrations and the lactate-to-pyruvate ratio during the lactate minimum speed test., J Sports Sci, volume 18, issue 3, pages 213-25, Mar 2000, doi [http://dx.doi.org/10.1080/026404100365117 10.1080/026404100365117], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10737272 10737272]</ref>
<ref name="MiyagiLeite2013">Willian Eiji Miyagi, Jorge Vieira de Mello Leite, Alessandro Moura Zagatto, Influência da seleção dos estágios incrementais sobre a intensidade de lactato mínimo: estudo piloto, Revista Brasileira de Cineantropometria e Desempenho Humano, volume 15, issue 6, 2013, ISSN [http://www.worldcat.org/issn/1980-0037 1980-0037], doi [http://dx.doi.org/10.5007/1980-0037.2013v15n6p715 10.5007/1980-0037.2013v15n6p715]</ref>
<ref name="Davies-2011">RC. Davies, AV. Rowlands, DC. Poole, AM. Jones, RG. Eston, Eccentric exercise-induced muscle damage dissociates the lactate and gas exchange thresholds., J Sports Sci, volume 29, issue 2, pages 181-9, Jan 2011, doi [http://dx.doi.org/10.1080/02640414.2010.526626 10.1080/02640414.2010.526626], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21170804 21170804]</ref>
<ref name="Mamen-2009">Mamen, Asgeir. "Estimating the Maximal Lactate Steady State Power from an Incremental Test Using Lactate Pro (R) LP1710." International Journal of Applied sports sciences (IJASS) 21.1 (2009): 74-85.</ref>
<ref name="Foxdal-1996">P. Foxdal, A. Sjödin, B. Sjödin, Comparison of blood lactate concentrations obtained during incremental and constant intensity exercise., Int J Sports Med, volume 17, issue 5, pages 360-5, Jul 1996, doi [http://dx.doi.org/10.1055/s-2007-972861 10.1055/s-2007-972861], PMID [http://www.ncbi.nlm.nih.gov/pubmed/8858408 8858408]</ref>
<ref name="HeadHolman2015">Megan L. Head, Luke Holman, Rob Lanfear, Andrew T. Kahn, Michael D. Jennions, The Extent and Consequences of P-Hacking in Science, PLOS Biology, volume 13, issue 3, 2015, pages e1002106, ISSN [http://www.worldcat.org/issn/1545-7885 1545-7885], doi [http://dx.doi.org/10.1371/journal.pbio.1002106 10.1371/journal.pbio.1002106]</ref>
<ref name="Palmer-1999">GS. Palmer, LB. Borghouts, TD. Noakes, JA. Hawley, Metabolic and performance responses to constant-load vs. variable-intensity exercise in trained cyclists., J Appl Physiol (1985), volume 87, issue 3, pages 1186-96, Sep 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10484594 10484594]</ref>
<ref name="Jones-2000">AM. Jones, H. Carter, The effect of endurance training on parameters of aerobic fitness., Sports Med, volume 29, issue 6, pages 373-86, Jun 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10870864 10870864]</ref>
<ref name="Donovan-1983">CM. Donovan, GA. Brooks, Endurance training affects lactate clearance, not lactate production., Am J Physiol, volume 244, issue 1, pages E83-92, Jan 1983, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6401405 6401405]</ref>
<ref name="Gleeson-1998">M. Gleeson, AK. Blannin, NP. Walsh, CN. Field, JC. Pritchard, Effect of exercise-induced muscle damage on the blood lactate response to incremental exercise in humans., Eur J Appl Physiol Occup Physiol, volume 77, issue 3, pages 292-5, Feb 1998, doi [http://dx.doi.org/10.1007/s004210050336 10.1007/s004210050336], PMID [http://www.ncbi.nlm.nih.gov/pubmed/9535593 9535593]</ref>
</references>
=What is Lactate?=
''Main article: [[Lactate]]''
At one time [[Lactate]] was viewed as a harmful waste product due anaerobic exercise, but research since the early 2000s has shown that Lactate is an intermediate fuel in the metabolism of carbohydrates. Muscles will burn Lactate in preference to Glucose, and will convert Lactate back to Glucose at rest. The level of Lactate in the blood is primarily dependent on exercise intensity. Note that Lactate forms Lactic Acid in the blood, and the terms are used interchangeably. Lactate is used as a fuel source by working muscles, and injecting extra lactate into the blood results in increased lactate metabolism and carbohydrate sparing<ref name="MillerFattor2002"/> without impairing performance<ref name="EllisSimmons2009"/>.
=What is the Lactate Threshold?=
The Lactate Threshold (LT) is the point at which the lactate level in the blood will rise even if the work intensity is kept constant. This is sometimes referred to as the Anaerobic Threshold (AT), or the Onset of Blood Lactate Accumulation (OBLA), though the most accurate term is Maximal Lactate Steady State (MLSS). Even within the scientific community terminology is confusing<ref name="Binder-2008"/>. It is sometimes believed that the MLSS represents the maximum clearance of Lactate, but this may not be the case<ref name="EllisSimmons2009"/>. Note that Lactate is normally measured in the blood stream, so the Lactate level reflects the net of the muscles releasing and absorbing Lactate.
Lactate Threshold is important as it is an excellent good predictor of race performance<ref name="Billat-1996"/><ref name="Palmer-1999"/><ref name="Baldari-2000"/><ref name="Jones-2000"/>. Lactate Threshold can be thought of as the percentage of VO2max that can be maintained for a protracted time<ref name="Costill-1973"/>, though it's not clear what the limiting factor is for exercise above the Lactate Threshold<ref name="Baron-2008"/>.
=Lactate Curve=
It is common to plot exercise intensity against lactate level to produce a blood lactate curve similar to the one below, showing an exponential rise in lactate level with intensity. It's generally accepted that a shift of the curve to the right indicates an improved athletic performance<ref name="Bosquet-2002"/><ref name="Yoshida-1990"/>, and training can improve performance because of this shift without a change in aerobic capacity ([[VO2max|V̇O<sub>2</sub>max]])<ref name="Acevedo-1989"/>. There is some limited evidence from radio-isotope studies in animals that a benefit of endurance training may be in Lactate clearance<ref name="Donovan-1983"/>. Note that above the Lactate Threshold the Lactate level is not at a steady state, but rises even though the intensity remains constant, so the typical curve that is shown is rather misleading.
[[File:Blood Lactate Curve.jpg|none|thumb|500px|A typically blood lactate curve with lactate level plotted against intensity.]]
=Lactate Threshold Training =
''Main article: [[Tempo Runs]]''
There is good evidence that endurance training changes Lactate Threshold. However, the idea that training at threshold intensity (Tempo Runs) is particularly effective has no evidence<ref name="Beneke-2011"/>"/><ref name="Guellich-2010"/>, and polarized training is a better approach<ref name="StögglSperlich2014"/><ref name="Muñoz-2014"/>. For trained athletes, Tempo runs are ineffective<ref name="Londeree-1997"/> and may actually be counterproductive<ref name="Evertsen-2001"/><ref name="Guellich-2010"/>. See [[Tempo Runs]] for more details.
Detraining shifts the curve to the left<ref name="Coyle-1985"/>. Lactate levels can be higher at a given intensity after just a few days without training<ref name="Mujika-2001"/>, suggesting rapid detraining effects.
=Determining Lactate Threshold=
There are various ways of determining the Lactate Threshold, each with their own problems.
* '''MLSS'''. The gold standard test (and the only one that appears to be valid) is to measure Maximal Lactate Steady State (MLSS). The test requires 3 to 5 constant intensity trials of at least 30 minutes' duration, each performed on separate days. Each test is at a different exercise intensity, and the highest intensity that does not have a rise in blood lactate in the last 20 minutes is the MLSS. While this is the best way of determining Lactate threshold, it's obviously time consuming and interferes with the athlete's regular training. Because of the effort of MLSS testing, various shortcuts have been tried.
* '''Fixed Blood Lactate Accumulation'''. A simple approach is to assume that Lactate Threshold always occurs at the same Lactate level. Sadly, this assumption is wrong, as Lactate Threshold can occur at vastly different levels.
* '''Lactate Patterns'''. There are various approaches that look at the pattern of change in Lactate in an attempt to create a simple test. So far, I've seen little evidence to support any of these approaches.
* '''Heart Rate Deflection'''. An indirect way of finding Lactate Threshold is to look for the [[Heart Rate Deflection]], sometimes called the "Conconi test". This test only requires a heart rate monitor to perform rather than blood draws, so it is much easier than the above approaches. However, the validity of the Conconi test has many issues and seems of dubious value<ref name="Cook2011"/>. See [[Heart Rate Deflection]] for details.
* '''Respiratory gasses'''. Another method for estimating Lactate Threshold is to measure the respiratory gasses<ref name="Binder-2008"/><ref name="Laplaud-2006"/>, but given this is impractical for most athletes, it's not covered here.
==Lactate Threshold & Maximal Lactate Steady State ==
The best approach to determine Lactate Threshold is to measure the Maximal Lactate Steady State (MLSS)<ref name="Faude-2009"/>. The test is actually several constant load trials of at least 30 minutes' duration on different days at various exercise intensities (in the range of 50–90% [[VO2max|V̇O<sub>2</sub>max]]. The highest workload that results in an increase of less than 1 mmol/L of lactate between the 10 and 30 minute mark defines the MLSS<ref name="Urhausen-1993"/><ref name="De SouzaGrossl2012"/><ref name="Beneke-2003"/>. Lactate is typically measured using a blood sample, either using a pinprick or a catheter. Note that MLSS for a given individual will vary by sport<ref name="Figueira-2008"/>, probably based on the mass of muscle engaged<ref name="Beneke-1996"/><ref name="Beneke-2003-2"/>. The difficulty of performing this test makes it impractical in most situations.
[[File:LactateMLSS.jpg|none|thumb|500px|Blood lactate levels over time at various workloads. The lower lines are at lower intensities, with the line marked MLSS being the highest intensity that produces stable lactate levels.]]
==Lactate Threshold & Incremental Power Test ==
A common approach to determine the Lactate Threshold is the Incremental Power Test. The subject exercises in stages of increasing intensity, with lactate measured at the end of each stage, with stages typically lasting 3 to 10 minutes. However, blood lactate takes 20-30 minutes to stabilize for a given intensity<ref name="Billat-1996"/>. This means that the incremental power test tends to be of limited value<ref name="Foxdal-1996"/>, with 3 minute stages giving low reproducibility<ref name="Morton-2012"/>, the stage length changing the lactate values<ref name="Faude-2009"/>, and even longer stages lengths of 8 minutes having low reproducibility<ref name="Gavin-2014"/>. The lactate level can drop between the 4<sup>th</sup> and 12<sup>th</sup> minute of exercise at a constant intensity<ref name="RieuMiladi1989"/>. Some have suggested using the lactate value measured as an indication of the prior stage's intensity, as it takes more than 3 minutes for lactate to stabilize<ref name="Orok-1989"/>, but this rather arbitrary approach can be used as a guideline (at best)<ref name="Baldari-2000"/>. For running, it is common to pause the exercise for 30 seconds to take a blood sample. These breaks only make a non-significant difference to the testing, though the slight difference tends to be greater at higher intensities<ref name="GullstrandSjüdin2007"/>.
==Lactate Threshold & Fixed Blood Lactate Accumulation==
Because MLSS is time consuming and expensive, a shortcut is often used to estimate MLSS by assuming that it occurs at a fixed Lactate Level (Fixed Blood Lactate Accumulation, or FBLA)<ref name="De SouzaGrossl2012"/>, unusually 4.0 mmol/l<ref name="Heck-1985"/> though sometimes 3.5 mmol/l<ref name="DenadaiFigueira2004"/><ref name="Denadai-2005"/>. However, while the MLSS may average around 4.0 mmol/l<ref name="Denadai-2005"/>, there are significant differences for individuals<ref name="Mamen-2009"/>, with variations between 3.0 and 5.5 in small sample sizes<ref name="Heck-1985"/> and has been shown to have a range as wide as 2.0 to 10.0 mmol/l<ref name="Faude-2009"/><ref name="Stegmann-1981"/>. This approach also typically uses a blood test, but in some sports (like running), the athlete has to pause to have a pinprick blood sample taken, further confusing the test<ref name="Heck-1985"/>. The term "Individual Anaerobic Threshold" (IAT) has been used to emphasize that the Lactate Threshold is specific to each individual rather than using a FBLA, though this can refer to a specific protocol for estimating MLSS<ref name="Stegmann-1981"/>. The Fixed Blood Lactate Accumulation is sometimes called "Onset of Blood Lactate Accumulation" (OBLA)<ref name="Mamen-2009"/>, a particularly misleading term in this context.
==Lactate Threshold Estimation From Lactate Patterns==
There have been several approaches to determining MLSS without the difficulty of the full protocol<ref name="Billat-1994"/><ref name="Harnish-2001"/><ref name="Palmer-1999"/><ref name="Tegtbur-1993"/><ref name="Dickhuth-1999"/><ref name="Urhausen-1993"/>, but their validity is limited<ref name="Kilding-2005"/><ref name="De SouzaGrossl2012"/><ref name="Beneke-1995"/>. These approaches generally look for some pattern in the change of Lactate level.
For example, one approach called the "Lactate Minimum Speed Test" (LMST) uses an initial sprint to elevate blood lactate followed by an incremental power test<ref name="SoteroPardono2009"/><ref name="Sotero-2009"/><ref name="MiyagiLeite2013"/>. However, the effectiveness of the LMST is profoundly impacted by the starting speed of the incremental portion of the test<ref name="Carter-1999"/>and so the results may be coincidence<ref name="Carter-2000"/>. This is not entirely surprising given the initial sprint phase disrupts the metabolism<ref name="Carter-2000"/>.
Part of the problem with these approaches may be that MLSS may not represent the point of maximum lactate clearance<ref name="Beneke-2003-2"/>, as injecting additional lactate into the blood of athletes exercising above MLSS did not significantly increase lactate levels<ref name="EllisSimmons2009"/>.
Some of the tests could be "p-hacking", where the study looks at a sufficiently large number of variables that some correlation occurs randomly<ref name="HeadHolman2015"/>.
[[File:LactateComp.jpg|none|thumb|500px|The correlation (or lack thereof) between MLSS and the lactate levels at the MLSS intensity seen during 3 or 5 minute incremental power tests<ref name="Heck-1985"/>.]]
=Factors that may influence Lactate Threshold=
There are a few factors that may change the Lactate Threshold (other than training)
* Because lactate is produced from the metabolism of carbohydrate, a reduction in carbohydrate intake (or [[Glycogen]] depletion) will shift the lactate curve to the right<ref name="Reilly-1999"/><ref name="Yoshida-1984"/><ref name="Maassen-1989"/><ref name="McLellan-1989"/>.
* It's not clear if [[Delayed Onset Muscle Soreness]] changes the lactate curve as there are reports that it does<ref name="Gleeson-1998"/> and reports that it does not<ref name="Davies-2011"/>.
* Lactate Threshold will vary by sport, probably based on the mass of muscle engaged<ref name="Beneke-1996"/>, or because the inactive muscles consume more lactate as the concentration rises<ref name="Orok-1989"/>. MLSS may also vary with environmental conditions, with a lower lactate levels at MLSS in hotter conditions<ref name="de Barros-2011"/>.
=Aerobic Threshold=
There is a related concept called "Aerobic Threshold" that is generally used to mean the exercise intensity at which Lactate levels rise above resting baselines<ref name="Faude-2009"/>. This threshold is believed to be the upper limit of nearly exclusive use of aerobic metabolism that can be sustained for many hours. Intensities just above the aerobic threshold can be maintained for prolonged periods (~4 hours)<ref name="Meyer-2003"/>. This aerobic threshold can be hard to determine in untrained subjects as it occurs at very low intensities<ref name="Seiler-2010"/>. Unfortunately, the term "Lactate Threshold" is sometimes used to mean this point where lactate rises above resting levels<ref name="Yoshida-1984"/>.
=References=
<references>
<ref name="Cook2011">I Cook, Was the Conconi test validated by sporting success, expert opinion or good science?, South African Journal for Research in Sport, Physical Education and Recreation, volume 33, issue 1, 2011, ISSN [http://www.worldcat.org/issn/0379-9069 0379-9069], doi [http://dx.doi.org/10.4314/sajrs.v33i1.65483 10.4314/sajrs.v33i1.65483]</ref>
<ref name="Beneke-1996">R. Beneke, SP. von Duvillard, Determination of maximal lactate steady state response in selected sports events., Med Sci Sports Exerc, volume 28, issue 2, pages 241-6, Feb 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8775160 8775160]</ref>
<ref name="Stegmann-1981">H. Stegmann, W. Kindermann, A. Schnabel, Lactate kinetics and individual anaerobic threshold., Int J Sports Med, volume 2, issue 3, pages 160-5, Aug 1981, doi [http://dx.doi.org/10.1055/s-2008-1034604 10.1055/s-2008-1034604], PMID [http://www.ncbi.nlm.nih.gov/pubmed/7333753 7333753]</ref>
<ref name="Heck-1985">H. Heck, A. Mader, G. Hess, S. Mücke, R. Müller, W. Hollmann, Justification of the 4-mmol/l lactate threshold., Int J Sports Med, volume 6, issue 3, pages 117-30, Jun 1985, doi [http://dx.doi.org/10.1055/s-2008-1025824 10.1055/s-2008-1025824], PMID [http://www.ncbi.nlm.nih.gov/pubmed/4030186 4030186]</ref>
<ref name="Faude-2009">O. Faude, W. Kindermann, T. Meyer, Lactate threshold concepts: how valid are they?, Sports Med, volume 39, issue 6, pages 469-90, 2009, PMID [http://www.ncbi.nlm.nih.gov/pubmed/19453206 19453206]</ref>
<ref name="De SouzaGrossl2012">Kristopher Mendes De Souza, Talita Grossl, Rubens José Babel Junior, Ricardo Dantas De Lucas, Vitor Pereira Costa, Luiz Guilherme Antonacci Guglielmo, Máximo estado estável de lactato estimado por diferentes métodos de determinação, Revista Brasileira de Cineantropometria e Desempenho Humano, volume 14, issue 3, 2012, ISSN [http://www.worldcat.org/issn/1980-0037 1980-0037], doi [http://dx.doi.org/10.5007/1980-0037.2012v14n3p264 10.5007/1980-0037.2012v14n3p264]</ref>
<ref name="Urhausen-1993">A. Urhausen, B. Coen, B. Weiler, W. Kindermann, Individual anaerobic threshold and maximum lactate steady state., Int J Sports Med, volume 14, issue 3, pages 134-9, Apr 1993, doi [http://dx.doi.org/10.1055/s-2007-1021157 10.1055/s-2007-1021157], PMID [http://www.ncbi.nlm.nih.gov/pubmed/8509241 8509241]</ref>
<ref name="Costill-1973">DL. Costill, H. Thomason, E. Roberts, Fractional utilization of the aerobic capacity during distance running., Med Sci Sports, volume 5, issue 4, pages 248-52, 1973, PMID [http://www.ncbi.nlm.nih.gov/pubmed/4774203 4774203]</ref>
<ref name="McLellan-1989">TM. McLellan, GC. Gass, The relationship between the ventilation and lactate thresholds following normal, low and high carbohydrate diets., Eur J Appl Physiol Occup Physiol, volume 58, issue 6, pages 568-76, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2731528 2731528]</ref>
<ref name="Maassen-1989">N. Maassen, MW. Busse, The relationship between lactic acid and work load: a measure for endurance capacity or an indicator of carbohydrate deficiency?, Eur J Appl Physiol Occup Physiol, volume 58, issue 7, pages 728-37, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2737193 2737193]</ref>
<ref name="Yoshida-1984">T. Yoshida, Effect of dietary modifications on lactate threshold and onset of blood lactate accumulation during incremental exercise., Eur J Appl Physiol Occup Physiol, volume 53, issue 3, pages 200-5, 1984, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6542853 6542853]</ref>
<ref name="Reilly-1999">T. Reilly, V. Woodbridge, Effects of moderate dietary manipulations on swim performance and on blood lactate-swimming velocity curves., Int J Sports Med, volume 20, issue 2, pages 93-7, Feb 1999, doi [http://dx.doi.org/10.1055/s-2007-971099 10.1055/s-2007-971099], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10190768 10190768]</ref>
<ref name="Coyle-1985">EF. Coyle, WH. Martin, SA. Bloomfield, OH. Lowry, JO. Holloszy, Effects of detraining on responses to submaximal exercise., J Appl Physiol (1985), volume 59, issue 3, pages 853-9, Sep 1985, PMID [http://www.ncbi.nlm.nih.gov/pubmed/3902770 3902770]</ref>
<ref name="Yoshida-1990">T. Yoshida, M. Udo, M. Chida, M. Ichioka, K. Makiguchi, T. Yamaguchi, Specificity of physiological adaptation to endurance training in distance runners and competitive walkers., Eur J Appl Physiol Occup Physiol, volume 61, issue 3-4, pages 197-201, 1990, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2282901 2282901]</ref>
<ref name="Acevedo-1989">EO. Acevedo, AH. Goldfarb, Increased training intensity effects on plasma lactate, ventilatory threshold, and endurance., Med Sci Sports Exerc, volume 21, issue 5, pages 563-8, Oct 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2607946 2607946]</ref>
<ref name="Bosquet-2002">L. Bosquet, L. Léger, P. Legros, Methods to determine aerobic endurance., Sports Med, volume 32, issue 11, pages 675-700, 2002, PMID [http://www.ncbi.nlm.nih.gov/pubmed/12196030 12196030]</ref>
<ref name="Beneke-2011">R. Beneke, RM. Leithäuser, O. Ochentel, Blood lactate diagnostics in exercise testing and training., Int J Sports Physiol Perform, volume 6, issue 1, pages 8-24, Mar 2011, PMID [http://www.ncbi.nlm.nih.gov/pubmed/21487146 21487146]</ref>
<ref name="Billat-1994">V. Billat, F. Dalmay, MT. Antonini, AP. Chassain, A method for determining the maximal steady state of blood lactate concentration from two levels of submaximal exercise., Eur J Appl Physiol Occup Physiol, volume 69, issue 3, pages 196-202, 1994, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8001529 8001529]</ref>
<ref name="Kilding-2005">AE. Kilding, AM. Jones, Validity of a single-visit protocol to estimate the maximum lactate steady state., Med Sci Sports Exerc, volume 37, issue 10, pages 1734-40, Oct 2005, PMID [http://www.ncbi.nlm.nih.gov/pubmed/16260974 16260974]</ref>
<ref name="Harnish-2001">CR. Harnish, TC. Swensen, RR. Pate, Methods for estimating the maximal lactate steady state in trained cyclists., Med Sci Sports Exerc, volume 33, issue 6, pages 1052-5, Jun 2001, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11404673 11404673]</ref>
<ref name="Palmer-1999">AS. Palmer, JA. Potteiger, KL. Nau, RJ. Tong, A 1-day maximal lactate steady-state assessment protocol for trained runners., Med Sci Sports Exerc, volume 31, issue 9, pages 1336-41, Sep 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10487377 10487377]</ref>
<ref name="Tegtbur-1993">U. Tegtbur, MW. Busse, KM. Braumann, Estimation of an individual equilibrium between lactate production and catabolism during exercise., Med Sci Sports Exerc, volume 25, issue 5, pages 620-7, May 1993, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8492691 8492691]</ref>
<ref name="Beneke-2003">R. Beneke, Methodological aspects of maximal lactate steady state-implications for performance testing., Eur J Appl Physiol, volume 89, issue 1, pages 95-9, Mar 2003, doi [http://dx.doi.org/10.1007/s00421-002-0783-1 10.1007/s00421-002-0783-1], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12627312 12627312]</ref>
<ref name="Stegmann-1981">H. Stegmann, W. Kindermann, A. Schnabel, Lactate kinetics and individual anaerobic threshold., Int J Sports Med, volume 2, issue 3, pages 160-5, Aug 1981, doi [http://dx.doi.org/10.1055/s-2008-1034604 10.1055/s-2008-1034604], PMID [http://www.ncbi.nlm.nih.gov/pubmed/7333753 7333753]</ref>
<ref name="Orok-1989">CJ. Orok, RL. Hughson, HJ. Green, JA. Thomson, Blood lactate responses in incremental exercise as predictors of constant load performance., Eur J Appl Physiol Occup Physiol, volume 59, issue 4, pages 262-7, 1989, PMID [http://www.ncbi.nlm.nih.gov/pubmed/2583172 2583172]</ref>
<ref name="Binder-2008">RK. Binder, M. Wonisch, U. Corra, A. Cohen-Solal, L. Vanhees, H. Saner, JP. Schmid, Methodological approach to the first and second lactate threshold in incremental cardiopulmonary exercise testing., Eur J Cardiovasc Prev Rehabil, volume 15, issue 6, pages 726-34, Dec 2008, doi [http://dx.doi.org/10.1097/HJR.0b013e328304fed4 10.1097/HJR.0b013e328304fed4], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19050438 19050438]</ref>
<ref name="Gavin-2014">JP. Gavin, ME. Willems, SD. Myers, Reproducibility of lactate markers during 4 and 8 min stage incremental running: a pilot study., J Sci Med Sport, volume 17, issue 6, pages 635-9, Nov 2014, doi [http://dx.doi.org/10.1016/j.jsams.2013.08.006 10.1016/j.jsams.2013.08.006], PMID [http://www.ncbi.nlm.nih.gov/pubmed/24028777 24028777]</ref>
<ref name="Morton-2012">RH. Morton, SR. Stannard, B. Kay, Low reproducibility of many lactate markers during incremental cycle exercise., Br J Sports Med, volume 46, issue 1, pages 64-9, Jan 2012, doi [http://dx.doi.org/10.1136/bjsm.2010.076380 10.1136/bjsm.2010.076380], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21343140 21343140]</ref>
<ref name="Dickhuth-1999">HH. Dickhuth, L. Yin, A. Niess, K. Röcker, F. Mayer, HC. Heitkamp, T. Horstmann, Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility., Int J Sports Med, volume 20, issue 2, pages 122-7, Feb 1999, doi [http://dx.doi.org/10.1055/s-2007-971105 10.1055/s-2007-971105], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10190774 10190774]</ref>
<ref name="Meyer-2003">T. Meyer, HH. Gabriel, M. Auracher, J. Scharhag, W. Kindermann, Metabolic profile of 4 h cycling in the field with varying amounts of carbohydrate supply., Eur J Appl Physiol, volume 88, issue 4-5, pages 431-7, Jan 2003, doi [http://dx.doi.org/10.1007/s00421-002-0712-3 10.1007/s00421-002-0712-3], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12527974 12527974]</ref>
<ref name="Billat-1996">LV. Billat, Use of blood lactate measurements for prediction of exercise performance and for control of training. Recommendations for long-distance running., Sports Med, volume 22, issue 3, pages 157-75, Sep 1996, PMID [http://www.ncbi.nlm.nih.gov/pubmed/8883213 8883213]</ref>
<ref name="EllisSimmons2009">Darren Ellis, Catherine Simmons, Benjamin F. Miller, Sodium lactate infusion during a cycling time-trial does not increase lactate concentration or decrease performance, European Journal of Sport Science, volume 9, issue 6, 2009, pages 367–374, ISSN [http://www.worldcat.org/issn/1746-1391 1746-1391], doi [http://dx.doi.org/10.1080/17461390903009158 10.1080/17461390903009158]</ref>
<ref name="MillerFattor2002">Benjamin F. Miller, Jill A. Fattor, Kevin A. Jacobs, Michael A. Horning, Franco Navazio, Michael I. Lindinger, George A. Brooks, Lactate and glucose interactions during rest and exercise in men: effect of exogenous lactate infusion, The Journal of Physiology, volume 544, issue 3, 2002, pages 963–975, ISSN [http://www.worldcat.org/issn/00223751 00223751], doi [http://dx.doi.org/10.1113/jphysiol.2002.027128 10.1113/jphysiol.2002.027128]</ref>
<ref name="Figueira-2008">TR. Figueira, F. Caputo, JG. Pelarigo, BS. Denadai, Influence of exercise mode and maximal lactate-steady-state concentration on the validity of OBLA to predict maximal lactate-steady-state in active individuals., J Sci Med Sport, volume 11, issue 3, pages 280-6, Jun 2008, doi [http://dx.doi.org/10.1016/j.jsams.2007.02.016 10.1016/j.jsams.2007.02.016], PMID [http://www.ncbi.nlm.nih.gov/pubmed/17553745 17553745]</ref>
<ref name="DenadaiFigueira2004">B.S. Denadai, T.R. Figueira, O.R.P. Favaro, M. Gonçalves, Effect of the aerobic capacity on the validity of the anaerobic threshold for determination of the maximal lactate steady state in cycling, Brazilian Journal of Medical and Biological Research, volume 37, issue 10, 2004, pages 1551–1556, ISSN [http://www.worldcat.org/issn/1678-4510 1678-4510], doi [http://dx.doi.org/10.1590/S0100-879X2004001000015 10.1590/S0100-879X2004001000015]</ref>
<ref name="Denadai-2005">BS. Denadai, EB. Gomide, CC. Greco, The relationship between onset of blood lactate accumulation, critical velocity, and maximal lactate steady state in soccer players., J Strength Cond Res, volume 19, issue 2, pages 364-8, May 2005, doi [http://dx.doi.org/10.1519/1533-4287(2005)19[364:TRBOOB]2.0.CO;2 10.1519/1533-4287(2005)19[364:TRBOOB]2.0.CO;2], PMID [http://www.ncbi.nlm.nih.gov/pubmed/15903376 15903376]</ref>
<ref name="Baron-2008">B. Baron, TD. Noakes, J. Dekerle, F. Moullan, S. Robin, R. Matran, P. Pelayo, Why does exercise terminate at the maximal lactate steady state intensity?, Br J Sports Med, volume 42, issue 10, pages 828-33, Oct 2008, doi [http://dx.doi.org/10.1136/bjsm.2007.040444 10.1136/bjsm.2007.040444], PMID [http://www.ncbi.nlm.nih.gov/pubmed/18070803 18070803]</ref>
<ref name="Laplaud-2006">D. Laplaud, M. Guinot, A. Favre-Juvin, P. Flore, Maximal lactate steady state determination with a single incremental test exercise., Eur J Appl Physiol, volume 96, issue 4, pages 446-52, Mar 2006, doi [http://dx.doi.org/10.1007/s00421-005-0086-4 10.1007/s00421-005-0086-4], PMID [http://www.ncbi.nlm.nih.gov/pubmed/16341873 16341873]</ref>
<ref name="Beneke-2003-2">R. Beneke, Maximal lactate steady state concentration (MLSS): experimental and modelling approaches., Eur J Appl Physiol, volume 88, issue 4-5, pages 361-9, Jan 2003, doi [http://dx.doi.org/10.1007/s00421-002-0713-2 10.1007/s00421-002-0713-2], PMID [http://www.ncbi.nlm.nih.gov/pubmed/12527964 12527964]</ref>
<ref name="Sotero-2009">RC. Sotero, E. Pardono, R. Landwehr, CS. Campbell, HG. Simoes, Blood glucose minimum predicts maximal lactate steady state on running., Int J Sports Med, volume 30, issue 9, pages 643-6, Sep 2009, doi [http://dx.doi.org/10.1055/s-0029-1220729 10.1055/s-0029-1220729], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19569005 19569005]</ref>
<ref name="de Barros-2011">CL. de Barros, TT. Mendes, LÁ. Mortimer, HG. Simões, LS. Prado, U. Wisloff, E. Silami-Garcia, Maximal lactate steady state is altered in the heat., Int J Sports Med, volume 32, issue 10, pages 749-53, Oct 2011, doi [http://dx.doi.org/10.1055/s-0031-1277191 10.1055/s-0031-1277191], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21590640 21590640]</ref>
<ref name="SoteroPardono2009">Rafael da Costa Sotero, Emerson Pardono, Carmen Sílvia Grubert Campbell, Herbert Gustavo Simões, Indirect Assessment of Lactate Minimum and Maximal Blood Lactate Steady-State Intensity for Physically Active Individuals, Journal of Strength and Conditioning Research, volume 23, issue 3, 2009, pages 847–853, ISSN [http://www.worldcat.org/issn/1064-8011 1064-8011], doi [http://dx.doi.org/10.1519/JSC.0b013e318196b609 10.1519/JSC.0b013e318196b609]</ref>
<ref name="Guellich-2010">A. Guellich, S. Seiler, Lactate profile changes in relation to training characteristics in junior elite cyclists., Int J Sports Physiol Perform, volume 5, issue 3, pages 316-27, Sep 2010, PMID [http://www.ncbi.nlm.nih.gov/pubmed/20861522 20861522]</ref>
<ref name="Seiler-2010">S. Seiler, What is best practice for training intensity and duration distribution in endurance athletes?, Int J Sports Physiol Perform, volume 5, issue 3, pages 276-91, Sep 2010, PMID [http://www.ncbi.nlm.nih.gov/pubmed/20861519 20861519]</ref>
<ref name="StögglSperlich2014">Thomas Stöggl, Billy Sperlich, Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training, Frontiers in Physiology, volume 5, 2014, ISSN [http://www.worldcat.org/issn/1664-042X 1664-042X], doi [http://dx.doi.org/10.3389/fphys.2014.00033 10.3389/fphys.2014.00033]</ref>
<ref name="Londeree-1997">BR. Londeree, Effect of training on lactate/ventilatory thresholds: a meta-analysis., Med Sci Sports Exerc, volume 29, issue 6, pages 837-43, Jun 1997, PMID [http://www.ncbi.nlm.nih.gov/pubmed/9219214 9219214]</ref>
<ref name="Evertsen-2001">F. Evertsen, JI. Medbø, A. Bonen, Effect of training intensity on muscle lactate transporters and lactate threshold of cross-country skiers., Acta Physiol Scand, volume 173, issue 2, pages 195-205, Oct 2001, doi [http://dx.doi.org/10.1046/j.1365-201X.2001.00871.x 10.1046/j.1365-201X.2001.00871.x], PMID [http://www.ncbi.nlm.nih.gov/pubmed/11683677 11683677]</ref>
<ref name="Baldari-2000">C. Baldari, L. Guidetti, A simple method for individual anaerobic threshold as predictor of max lactate steady state., Med Sci Sports Exerc, volume 32, issue 10, pages 1798-802, Oct 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11039656 11039656]</ref>
<ref name="Muñoz-2014">I. Muñoz, S. Seiler, J. Bautista, J. España, E. Larumbe, J. Esteve-Lanao, Does polarized training improve performance in recreational runners?, Int J Sports Physiol Perform, volume 9, issue 2, pages 265-72, Mar 2014, doi [http://dx.doi.org/10.1123/ijspp.2012-0350 10.1123/ijspp.2012-0350], PMID [http://www.ncbi.nlm.nih.gov/pubmed/23752040 23752040]</ref>
<ref name="Beneke-1995">R. Beneke, Anaerobic threshold, individual anaerobic threshold, and maximal lactate steady state in rowing., Med Sci Sports Exerc, volume 27, issue 6, pages 863-7, Jun 1995, PMID [http://www.ncbi.nlm.nih.gov/pubmed/7658947 7658947]</ref>
<ref name="RieuMiladi1989">M. Rieu, J. Miladi, A. Ferry, A. Duvallet, Blood lactate during submaximal exercises, European Journal of Applied Physiology and Occupational Physiology, volume 59, issue 1-2, 1989, pages 73–79, ISSN [http://www.worldcat.org/issn/0301-5548 0301-5548], doi [http://dx.doi.org/10.1007/BF02396583 10.1007/BF02396583]</ref>
<ref name="Mujika-2001">I. Mujika, S. Padilla, Cardiorespiratory and metabolic characteristics of detraining in humans., Med Sci Sports Exerc, volume 33, issue 3, pages 413-21, Mar 2001, PMID [http://www.ncbi.nlm.nih.gov/pubmed/11252068 11252068]</ref>
<ref name="GullstrandSjüdin2007">L. Gullstrand, B. Sjüdin, J. Svedenhag, Blood sampling during continuous running and 30-second intervals on a treadmill, Scandinavian Journal of Medicine & Science in Sports, volume 4, issue 4, 2007, pages 239–242, ISSN [http://www.worldcat.org/issn/09057188 09057188], doi [http://dx.doi.org/10.1111/j.1600-0838.1994.tb00434.x 10.1111/j.1600-0838.1994.tb00434.x]</ref>
<ref name="Carter-1999">H. Carter, AM. Jones, JH. Doust, Effect of incremental test protocol on the lactate minimum speed., Med Sci Sports Exerc, volume 31, issue 6, pages 837-45, Jun 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10378911 10378911]</ref>
<ref name="Carter-2000">H. Carter, AM. Jones, JH. Doust, Changes in blood lactate and pyruvate concentrations and the lactate-to-pyruvate ratio during the lactate minimum speed test., J Sports Sci, volume 18, issue 3, pages 213-25, Mar 2000, doi [http://dx.doi.org/10.1080/026404100365117 10.1080/026404100365117], PMID [http://www.ncbi.nlm.nih.gov/pubmed/10737272 10737272]</ref>
<ref name="MiyagiLeite2013">Willian Eiji Miyagi, Jorge Vieira de Mello Leite, Alessandro Moura Zagatto, Influência da seleção dos estágios incrementais sobre a intensidade de lactato mínimo: estudo piloto, Revista Brasileira de Cineantropometria e Desempenho Humano, volume 15, issue 6, 2013, ISSN [http://www.worldcat.org/issn/1980-0037 1980-0037], doi [http://dx.doi.org/10.5007/1980-0037.2013v15n6p715 10.5007/1980-0037.2013v15n6p715]</ref>
<ref name="Davies-2011">RC. Davies, AV. Rowlands, DC. Poole, AM. Jones, RG. Eston, Eccentric exercise-induced muscle damage dissociates the lactate and gas exchange thresholds., J Sports Sci, volume 29, issue 2, pages 181-9, Jan 2011, doi [http://dx.doi.org/10.1080/02640414.2010.526626 10.1080/02640414.2010.526626], PMID [http://www.ncbi.nlm.nih.gov/pubmed/21170804 21170804]</ref>
<ref name="Mamen-2009">Mamen, Asgeir. "Estimating the Maximal Lactate Steady State Power from an Incremental Test Using Lactate Pro (R) LP1710." International Journal of Applied sports sciences (IJASS) 21.1 (2009): 74-85.</ref>
<ref name="Foxdal-1996">P. Foxdal, A. Sjödin, B. Sjödin, Comparison of blood lactate concentrations obtained during incremental and constant intensity exercise., Int J Sports Med, volume 17, issue 5, pages 360-5, Jul 1996, doi [http://dx.doi.org/10.1055/s-2007-972861 10.1055/s-2007-972861], PMID [http://www.ncbi.nlm.nih.gov/pubmed/8858408 8858408]</ref>
<ref name="HeadHolman2015">Megan L. Head, Luke Holman, Rob Lanfear, Andrew T. Kahn, Michael D. Jennions, The Extent and Consequences of P-Hacking in Science, PLOS Biology, volume 13, issue 3, 2015, pages e1002106, ISSN [http://www.worldcat.org/issn/1545-7885 1545-7885], doi [http://dx.doi.org/10.1371/journal.pbio.1002106 10.1371/journal.pbio.1002106]</ref>
<ref name="Palmer-1999">GS. Palmer, LB. Borghouts, TD. Noakes, JA. Hawley, Metabolic and performance responses to constant-load vs. variable-intensity exercise in trained cyclists., J Appl Physiol (1985), volume 87, issue 3, pages 1186-96, Sep 1999, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10484594 10484594]</ref>
<ref name="Jones-2000">AM. Jones, H. Carter, The effect of endurance training on parameters of aerobic fitness., Sports Med, volume 29, issue 6, pages 373-86, Jun 2000, PMID [http://www.ncbi.nlm.nih.gov/pubmed/10870864 10870864]</ref>
<ref name="Donovan-1983">CM. Donovan, GA. Brooks, Endurance training affects lactate clearance, not lactate production., Am J Physiol, volume 244, issue 1, pages E83-92, Jan 1983, PMID [http://www.ncbi.nlm.nih.gov/pubmed/6401405 6401405]</ref>
<ref name="Gleeson-1998">M. Gleeson, AK. Blannin, NP. Walsh, CN. Field, JC. Pritchard, Effect of exercise-induced muscle damage on the blood lactate response to incremental exercise in humans., Eur J Appl Physiol Occup Physiol, volume 77, issue 3, pages 292-5, Feb 1998, doi [http://dx.doi.org/10.1007/s004210050336 10.1007/s004210050336], PMID [http://www.ncbi.nlm.nih.gov/pubmed/9535593 9535593]</ref>
</references>
