Learn what threshold means, why different tests produce different anchors, and how to interpret controlled hard work without equating a percentage band with a measured boundary.
Threshold is a common coaching label for sustained hard work. The app's fourth percentage band is not a measurement of lactate threshold, critical power or FTP.
How it feels
Hard, with limited comfortable speech
Why use it
Practice controlled demanding work
An example
Controlled hard repetitions paced so that the planned work can be completed consistently.
These names describe this guide’s five-zone convention. Thresholds, effort and useful session duration vary with your zone system, sport and individual testing.
Treat Threshold as a label until the method is known
The app places Zone 4 at 80–90% of maximum heart rate, or 80–90% of reserve added to resting heart rate. The label Threshold does not mean either boundary measures your second threshold. Percentage bands and physiological anchors are different layers of information.
When someone gives you a threshold target, ask what was measured, how it was measured, in which activity and when. A heart-rate value from running cannot automatically establish a cycling power target, and a pace estimate cannot supply a lactate concentration.
LT2, ventilatory landmarks, MLSS, FTP and critical power
These terms describe measurements or models developed for different purposes. A second lactate threshold comes from interpreting a lactate response; a ventilatory landmark comes from gas exchange; maximal lactate steady state uses repeated constant-load testing. Critical power or speed is estimated from the relationship between performance and duration.
FTP is a practical cycling performance anchor whose meaning depends on the test or estimation method. None of these terms should be silently replaced with another. Even when values are close for a person, agreement must be established rather than assumed from the word threshold.
A threshold-style workout generally asks you to sustain demanding work with control rather than turn every repetition into a maximum effort. Useful observations include whether the output stayed consistent, whether the final work segment resembled the first, and whether the session matched its planned purpose.
There is no universal repetition duration or recovery rule attached to a zone number. The appropriate structure depends on the athlete, event, metric and phase of training. An example on this site illustrates how a session fits together; it does not establish personal readiness or the right dose.
Read a segment rather than one isolated bpm value
Compare heart rate and output from the same work segment. A whole-session average mixes preparation, work and recoveries, while a peak may be brief or affected by the signal. If the numbers conflict, inspect timing, conditions and sensor quality before changing a training anchor.
Repeating a familiar segment under similar conditions can help you recognize what is usual. Still, an unexpected heart-rate response is not enough to infer overtraining, dehydration or a new threshold. Record the context and avoid assigning a diagnosis to a chart.
Threshold-centered training is one distribution pattern studied alongside high-volume, high-intensity and polarized approaches. Their results depend on the actual intervention and participants. A paper that favors one pattern for a laboratory measure does not mean threshold work has no purpose.
Review it alongside the week's other demanding sessions and long outings. If adding a threshold session means every day becomes hard, reconsider the structure rather than trying to fix it by shifting a bpm boundary. Keep the easier days and the purpose of the training block visible.
The examples in this guide illustrate training concepts. Percentage bands and planning heuristics are identified as conventions; they do not measure your individual thresholds. The research library describes study populations, methods, outcomes, and limitations.
Oliveira, Boppre and Fonseca · 2024 · Systematic review and meta-analysis of controlled training interventions; searches through October 2022.
Practical interpretation: Assess the outcome you want to improve. A VO2peak advantage does not establish a universally superior race plan or a mandatory 80/20 split.
Limits: Interventions and comparators differed, participants were predominantly male, and study durations were generally short. Publication year does not mean the search included 2024 studies.
Jamnick, Pettitt, Granata, Pyne and Bishop · 2020 · Critical review of measurement methods and their relationship to exercise-intensity domains.
Practical interpretation: Name the method and measurement. Do not treat LT2, a fixed lactate value, FTP and critical power as automatically equivalent.
Limits: Method validity for acute responses does not itself establish which prescription produces the best long-term training adaptation.
Gillinov and colleagues · 2017 · Device-validation experiment comparing contemporaneous wearable readings with ECG.
Practical interpretation: Check signal quality before interpreting a sudden zone change. Compare sensors when an unexpected reading drives a training decision.
Limits: Specific 2017 devices and laboratory conditions. These results cannot rank today's hardware or guarantee that every chest-strap reading is correct.
Meyer, Gabriel and Kindermann · 1999 · Incremental cycling-test analysis comparing fixed percentages with individual anaerobic threshold.
Practical interpretation: A percentage band is a starting convention. Its boundaries should not be presented as individually verified physiological landmarks.
Limits: Specific male athlete sample and threshold definition. It did not test whether a percentage-based training plan could still be useful.
