Grant Giles’s threshold essay favors felt effort over number chasing. A 2026 review adds context on the talk test and its limits for endurance athletes.
Grant Giles published his short training essay “Anaerobic Threshold” on October 20, 2026. His central coaching argument is straightforward: threshold sessions deserve close attention to felt effort and movement rather than an overriding commitment to pace, power, or heart-rate readings.
That perspective has a useful scientific companion. A 2026 narrative review in British Medical Bulletin examined noninvasive threshold assessment in endurance athletes. Its discussion of the talk test helps put Giles’s emphasis on internal attention into context without turning his coaching judgment into a research finding.
Giles frames threshold as “the point between accumulation and clearance.” That is his coaching description rather than a formal definition established by his essay. He treats numerical outputs as information about the effort rather than the best inputs for managing it.
The practical distinction is between producing a number and attending to the work behind it. In Giles’s account, an athlete can become too governed by the pace or power achieved in an earlier session. His alternative is close observation of bodily sensations and movement with subtle adjustments as the effort develops.
Read this as an argument about attention. The question is not simply whether a target appeared on the screen. It is whether the athlete remained attentive to the experience of producing that output.
That gives perceived effort a different role from a performance result. A pace describes an output. Giles’s coaching perspective asks the athlete to notice how the work feels rather than allowing that output to dictate the entire session.
The British Medical Bulletin review approaches a related question from the assessment side. It describes the talk test as a way to infer exercise intensity from how comfortably someone can speak. Because it requires no equipment, the authors rate its field feasibility as very high.
The connection between the sources is useful but specific. Giles argues for greater attention to internal experience. The review evaluates methods that include a speech-based cue. Reading them together supports considering subjective information alongside recorded outputs rather than treating either as the whole picture.
The two sources carry different kinds of authority. Giles’s essay expresses coaching judgment. It reports no training experiment, athlete sample, or statistical comparison showing that attention to movement improves threshold performance.
It also does not provide a standardized breathing test or a target perceived-exertion rating. There is no workout prescription or validated procedure to reproduce. Turning the essay into a detailed threshold protocol would therefore go beyond what Giles supplied.
The review offers a broader evidence base. It synthesized 88 reports on noninvasive threshold assessment but did not conduct a meta-analysis. Its conclusions are a narrative assessment of available research rather than a quantitatively pooled estimate of accuracy.
For the talk test, the authors describe resolution as coarse. First difficulty speaking can approximate ventilatory threshold in some settings. In some cohorts, the relationship is closer to lactate threshold. The review consequently characterizes the method as less suitable for precise or high-intensity exercise prescription and not an exact replacement for laboratory assessment.
There is also a terminology issue. The review distinguishes ventilatory threshold and lactate threshold from respiratory compensation threshold and maximal lactate steady state. These are related concepts rather than interchangeable names for one boundary. A practical sensation should not be presented as identifying all of them precisely.
Finally, these sources do not establish a wider move away from device-based training. One is an individual coach’s argument and the other evaluates assessment methods. Neither documents an industry-wide change in how endurance athletes train.
For endurance athletes aged 35 to 65, the relevance is practical rather than age-specific. Neither source provides age-specific prescriptions or demonstrates distinct benefits for this age group. The useful translation is a way to think about threshold work while retaining the broader training plan.
At Reendure, our focus is translating sports science into practical guidance for athletes over 35. Here, that means keeping an ambitious training goal separate from an assumption that every previous output must be repeated. Giles’s perspective offers a prompt for attention rather than a reason to abandon structured training.
A pace or power target can remain part of the session’s context. The coaching adjustment is to consider it alongside bodily sensation and movement rather than allowing it to settle every question about the effort.
Under Giles’s framing, a previous result is something to understand rather than automatically reproduce. That distinction leaves room to ask whether the current effort still feels controlled. It also keeps the purpose of the session in view instead of making numerical matching the only criterion that matters.
For a broader discussion of this relationship, our guide to reading training data alongside perceived effort considers those measures together. The relevant editorial principle is that information from the athlete belongs in the discussion with information from the device.
Giles’s practical emphasis is on noticing sensations and movement while making subtle adjustments. Translating that into training does not require attaching a new numerical score to every sensation.
Useful questions drawn from his coaching perspective include:
These are prompts for reflection rather than a sequence for locating a physiological boundary. Their value within Giles’s argument is to bring attention back to the effort being performed.
Our explanation of using perceived exertion as a training tool provides a broader place to consider that skill. It is a separate discussion from assigning a laboratory meaning to one sensation.
The review suggests a useful distinction between adding context and seeking precision. A speech-based cue belongs naturally in a discussion of how an effort feels. When the question concerns a specific threshold value, the assessment needs to match the threshold being discussed.
For an athlete working with a qualified coach or exercise-testing professional, that creates a clear conversation: which threshold is relevant and how was it assessed? Establishing that shared meaning is more useful than assuming that everyone uses “threshold” in exactly the same way.
This is also a reason to keep coaching language and measurement language distinct. A phrase that helps an athlete manage effort can serve its purpose without being treated as a laboratory result. The practical task is to use each kind of information for the question it actually addresses.
Giles’s essay makes a focused coaching case: threshold training should involve attention to felt effort and movement rather than fixation on numerical outputs. The accompanying review gives speech-based assessment a place in that discussion while defining its appropriate role.
For the veteran endurance athlete, the modest takeaway is to keep both the output and the experience in view. Let the training numbers inform the session while giving bodily sensations a place in how the work is understood. The available evidence supports that measured perspective without requiring a wholesale change to training.
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