The anaerobic threshold: 50+ years of controversy.
Level 5 - mechanism / opinion, no new human data
Narrative conceptual review and mechanism-based reasoning without new empirical data.
PubMed 33112439 · doi:10.1113/JP279963
What was done
This paper is a historical and physiological review analyzing the 50-year controversy surrounding the "anaerobic threshold" (AT) concept originally proposed by Karlman Wasserman. It traces the theoretical framework linking muscle oxygenation, blood lactate accumulation, and gas exchange dynamics, and evaluates the concept against modern lactate shuttle biology and exercise energetics.
What was found
The abstract provides no empirical numbers or quantitative data. Conceptually, it establishes that muscle anoxia or dysoxia is not the cause of elevated blood lactate during exercise; rather, lactataemia results from increased glycolytic flux outstripping lactate clearance. Furthermore, sustained non-oxidative exercise energetics correspond to critical power rather than the lactate threshold. Non-invasive estimation using the gas exchange threshold remains clinically and practically useful, but requires updated mechanistic interpretation.
Why it matters
It decouples widely used clinical and athletic testing concepts (such as the gas exchange threshold) from the disproven hypothesis of exercise-induced muscle tissue hypoxia, aligning practical exercise testing with modern metabolic biochemistry.
Limits
As a narrative review, it presents no new experimental data, statistical analyses, or participant cohorts. It relies on qualitative conceptual synthesis, leaving the comparative precision and clinical reliability of specific testing protocols unquantified in the abstract.
Cited by
- supports Ventilatory threshold 1 (VT1) corresponds to the aerobic threshold where conversation becomes difficult, while ventilatory threshold 2 (VT2) corresponds to the anaerobic threshold where lactic acid accumulates faster than it can be cleared.