REF-173 · Jamnick et al., 2020 · Sports Medicine, · Paper

An Examination and Critique of Current Methods to Determine Exercise Intensity

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

Jamnick et al. evaluate the construct validity of methods for prescribing exercise intensity by one criterion: does the method provoke homeostatic disturbances (e.g. VO2 kinetics, blood lactate) consistent with the moderate, heavy and severe domains?

Methods reviewed: fixed percentages of maximal anchors from a graded exercise test (VO2max/VO2peak, HRmax, maximal work rate — power or velocity), and submaximal anchors (VT, GET, RCP, LT1, LT2, MLSS, critical power CP, critical speed CS).

Conclusions: a fixed percentage of a maximal anchor "has little merit" for eliciting distinct, domain-specific perturbations; there is some evidence that LT1, GET and VT delineate the moderate-heavy boundary; for the heavy-severe boundary there is little evidence for most commonly used methods, with the exception of CP and CS.

Acute responses do not guarantee chronic adaptations — training studies are needed to verify whether the prescription method changes the training outcome.

Key Findings (from the abstract)

Fixed %VO2max, %HRmax or %maximal work rate: little merit for placing athletes in a chosen domain.
Moderate-heavy boundary: some support for LT1, GET and VT.
Heavy-severe boundary: little support for most methods; CP and CS are the exceptions.
Prescription method vs adaptation: not yet tested — acute physiology is a proxy until training studies compare methods.
The review gives no error percentages for any method; any "±X% domain error" figure quoted from earlier versions of this entry was invented.

Practical Application

Fixed percentages of HRmax, VO2max or maximal power have little merit for putting an athlete in a chosen intensity domain; the moderate-heavy boundary is best anchored to LT1/GET/VT and the heavy-severe boundary to critical power or critical speed — those are the methods this review finds evidence for (narrative critical review, Jamnick 2020).
For VO2max/severe-domain intervals, anchor to CP (or CS in running), not to a %HRmax band — the same %HRmax can sit in different domains in different athletes.
For "Zone 2" / moderate work, an LT1, GET or VT measurement is the supported anchor.
Inference, not tested: FTP is a field proxy that the review does not list among validated boundary markers; treat FTP-derived "threshold" zones as approximations of the heavy-severe boundary, and check them against a CP estimate where possible.
Not from this paper; the base's own practice: RPE is used as a backup domain check (conversational = moderate, laboured = heavy, unsustainable = severe). The review evaluates physiological anchors, not RPE mappings.

Limitations

From the design as the abstract reports it: a narrative critical review — no systematic search or pooled analysis is described, and methods are judged by one construct criterion (whether they provoke homeostatic disturbances consistent with the moderate, heavy and severe domains).
The evidence concerns acute physiological responses; the authors state that acute responses are not always predictive of chronic adaptations and that training studies are required to verify whether the prescription method changes adaptation.
The abstract gives no error margins for any method, so how far fixed-percentage anchors misplace athletes is not quantified here.
How this entry was checked and changed
Why this level

regraded 2026-09-27 from A: narrative review from a leading group (Jamnick, Bishop), no systematic method or pooled data

Content correction 2026-09-27
All "Key Figures" (%HRmax ±15%, %VO2max ±10-12%, FTP vs CP 5-10%, domain-based <5% error) deleted: the review reports no such error percentages.
"Only LT1 and LT2/CP ensure correct domain entry" -> abstract: LT1/GET/VT have some support for the moderate-heavy boundary; only CP and CS have support for the heavy-severe boundary; LT2 is not among the supported markers.
RPE ladder (6-7/10 heavy, 8-9/10 severe) removed as a finding; RPE kept only as the base's own practice.
Level A -> B+: narrative critical review, not a systematic critique.
2026-09-28: added Limitations from the abstract (Europe PMC PMID 32729096).