Scientific Programme
Exchange Symposia
IS-EX03 - ACSM-ECSS exchange symposium: Lactate metabolism
Date: 02.07.2025, Time: 11:00 - 12:15, Session Room: Anfiteatro
Description
Lactate (La-) metabolism has long been a controversial topic in research, clinical, and athletic settings. Since its discovery in 1780, La- has often been erroneously viewed as simply a hypoxic waste product with multiple deleterious effects. Not until the 1980s, with the introduction of the cell-to-cell lactate shuttle did a paradigm shift in our understanding of the role of La- in metabolism begin. The evidence for La- as a major player in the coordination of whole-body metabolism has since grown rapidly. La- is a readily combusted fuel that is shuttled throughout the body. Through rapid multisystem exchange involving membrane monocarboxylate transporters, lactate concentration ([La-]) in the blood offers a partial "snapshot" of relative rates of glycolytic La- production and its mitochondrial consumption. Thus, while strenuous physical activity elicits a transient La- accumulation, adaptations to exercise training often include attenuated [La-]s for a given submaximal work rate, as well as lower [La-]s at rest. Despite these new perspectives, many fundamental discoveries about La- are still working their way into mainstream research, clinical care, and practice. Beyond the basic mechanisms, various indices of La- metabolism are central to our understanding of performance, assessment, and training in athletes. Primary among these are the La- and gas exchange thresholds, maximal La- steady state and its relationship to critical power/speed and the use of peak and recovery La- dynamics to evaluate ‘anaerobic capacity’. These exchange lectures will synthesize current understanding of La- metabolism from basic physiology/biochemistry to applied sports considerations.
Chair(s)
Romain Meeusen
Vrije Universiteit Brussel, Human Physiology Research Lab
Belgium
Speaker A
Bruce Gladden
Auburn University, School of Kinesiology
United States
Read CVECSS Rimini 2025: IS-EX03
Lactate Metabolism: From Hypoxia to Shuttles
Lactate (La-) stands at the crossroads of glycolytic and oxidative energy metabolism. Studies of exercise and muscle metabolism from the 1700s to the mid-twentieth century asserted that La- is the product of anaerobic glycolysis, with “anaerobic” implying a lack or absence of oxygen (O2) availability for mitochondria. However, it is now appreciated that healthy mitochondria function well, even at low O2 levels such that dysoxia (O2 levels so low that mitochondrial oxidative phosphorylation is inhibited) is rare and low O2 is often a minor factor in the increasing concentrations of La- typically observed with exercise or even many acute critical care situations. Instead the basic mechanisms underlying La- production, removal, and accumulation emphasize stimulation of key glycolytic enzyme activities, limitations to lactate removal, and the distribution of La- among cells throughout the body and even within tumors. From its role in coordinating whole-body metabolism as a fuel to its role as a signaling molecule in tumors, the study of La- metabolism continues to expand and holds potential for multiple clinical applications. Various aspects of the history of La- metabolism, as well as the structures, processes and mechanism of La- appearance, disappearance, and exchange will be examined.
Speaker B
Andrew Jones
Exeter University, Sport and Health Sciences
United Kingdom
Read CVECSS Rimini 2025: IS-EX03
Lactate: its use (and misuse) in sport
Measurement of blood [La-] during exercise is a mainstay of fitness assessment, performance estimation and training prescription in athletes. However, the application and interpretation of such measurements has been mired in controversy. This presentation will outline several misunderstandings regarding the role of La- in exercise performance, particularly in relation to its role, or otherwise, in fatigue development. Despite these misconceptions, blood La- measurements continue to be valuable if used appropriately. Blood La- dynamics during exercise typically reflect changes in other muscle metabolites that might be more directly involved in fatigue development and help identify exercise intensity domains within which broader physiological responses are manifest - with implications for adaptations to training. While the La- threshold, or its pulmonary gas exchange counterpart, continues to find application in clinical settings, the highest exercise speed that can be sustained in a metabolic (including La-) ‘steady state’ is of particular importance in endurance sports. New approaches for defining this transition point will be described and the future directions for La- monitoring in athlete evaluation, training intensity assessment and exercise prescription will be considered.
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