REF-171 · Keir et al., 2022 · Sports Medicine, · Paper

Identification of Non-Invasive Exercise Thresholds: Methods, Strategies, and an Online App

B+moderate evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Keir, Iannetta, Mattioni Maturana, Kowalchuk & Murias give a theoretical and practical resource for identifying the two thresholds visible in standard gas exchange and ventilatory measurements during incremental exercise: the first signifies the onset of blood lactate accumulation (the lactate threshold, LT — estimated non-invasively as θLT) and the second the onset of metabolic acidosis (the respiratory compensation point, RCP).

The review is written for instructors, clinicians, researchers, lab technicians and students, and introduces an online application for identifying the estimated LT and RCP from real incremental-exercise data.

Key Findings — what the review covers (its four stated objectives)

1

The underlying physiology that produces the LT and the RCP

2

The classic non-invasive measurements by which these thresholds are identified, connecting the variable profiles to the underlying physiological behaviour

3

Common issues that can obscure threshold detection, and strategies to identify and mitigate them

4

An online resource to standardise practice: a novel application that identifies the estimated LT (θLT) and RCP, offered both as a learning platform on real exercise data and as an analysis tool for anyone with incremental-exercise data

Worked examples of gas exchange and ventilatory data are provided throughout (abstract).

Practical Application

Methodological review with an online app: the two non-invasive thresholds of an incremental test — the estimated lactate threshold (θLT, onset of lactate accumulation) and the respiratory compensation point (RCP, onset of metabolic acidosis) — are explained physiologically, identified from standard gas exchange and ventilatory variables, protected against common detection problems, and can be computed with the authors' online application. Standardise how thresholds are read before trusting how they change.
Use the review's structured approach when a lab report gives VT1/VT2 numbers: know which variables the threshold was read from and whether detection issues (noise, protocol, breathing pattern) were handled — the abstract's third objective.
Not from this paper; the base's own practice: identify each threshold from more than one variable profile and, when possible, run the data through the authors' app as a second reader; the review itself does not specify a required number of methods.
For the lactate-side terminology (first and second lactate threshold, three-phase model) see REF-170; for protocol effects on threshold validity see REF-031.

Limitations

Narrative teaching review; no data comparing methods, no reproducibility figures in the abstract; the online app is introduced, not validated against invasive measures here.

How this entry was checked and changed
Why this level

regraded 2026-09-27 from A: narrative methodological review from a leading threshold group, no systematic method, no meta-analysis

Content correction 2026-09-27
"Non-standardized approach → ±10-15% threshold determination error", "Error with standardization: <5% CV", "Error without standardization: 10-15% CV" -> not in the abstract; deleted.
"V-slope method most objective", "confirm via VE/VO2", "RCP via VE/VCO2 breakpoint and PETCO2", "use ≥2 independent methods" -> specific method names and a method count are not in the abstract; replaced by the abstract's four objectives; the multi-variable habit relabelled base practice.
Level A ("systematic, with online app") -> B+: a narrative methodological review, not a systematic review.
Cross-reference labels pointed at the wrong entry or named the wrong author (checked against each cited entry's byline); repointed to the entry the label describes, or removed where the base holds no such paper.