Threshold pace and tempo runs explained
Distinguish threshold, tempo and intervals. Learn what a defined session needs and why a race estimate is different from a physiological measurement.
In this article
Tempo, threshold and intervals are not interchangeable labels. Tempo can mean different things; threshold requires a definition; intervals describe how work and recovery are organised rather than one specific intensity.
If a plan says only “twenty minutes tempo”, information is missing. Clarify the purpose and how to recognise the intended effort before simply running faster.
What does threshold mean?
Exercise physiology uses different thresholds and methods to identify them. Lactate, ventilation and critical-speed references are related but should not be presented as identical measurements. Definitions and testing protocols matter. Lactate diagnostics review and intensity in endurance runners.
When someone says a threshold improved, ask what changed and how it was measured. A faster workout alone does not establish which physiological mechanism changed.
Tempo needs additional instructions
Instead of arguing over the correct word, look for the components that make a workout usable:
| Component | Question it answers |
|---|---|
| Purpose | What are we trying to train? |
| Reference | Estimated pace, sensation or an individual measurement? |
| Work duration | How long is each effort? |
| Recovery | How long, and what activity? |
| Context | What comes before and after? |
| Adjustment | What changes if effort is not as intended? |
A label can abbreviate a conversation when runner and coach share definitions. An online plan should not assume that shared understanding.
Continuous running and intervals change the structure
Consider two arithmetic examples, not prescriptions: eighteen continuous minutes, or three six-minute blocks separated by recovery. Both accumulate eighteen work minutes, but their organisation differs.
Equal minutes do not establish equal load, intensity or effect. The other components still matter. Replacing twenty continuous minutes with faster repeats while retaining the threshold label changes the task.
Fartlek also alternates effort, but does not independently define a physiological threshold. Session names should not replace instructions.
An estimate differs from a measurement
Entering a result into the VDOT calculator provides a performance reference and approximate paces. It does not measure blood lactate or respiratory gas exchange.
For a professionally conducted test, keep the date and definition used. Identify an estimate as an estimate. Mixing estimated and measured values without explanation creates misleading precision.
You do not need to perform an unsupervised maximal test to read this article or begin organising training. Test suitability depends on preparation and health.
Describe what happened before explaining why
Instead of “my threshold has worsened”, record: “I could not sustain the planned block; conditions were hotter and the effort felt harder.” That preserves observations without prematurely assigning a mechanism.
Review whether the pace reference is recent, conditions comparable and preceding load appropriate. The perceived-effort guide helps describe a session, not measure threshold.
A useful record includes completed duration, recovery, effort and reasons for changes. Several comparable observations support a better review than a single success-or-failure label.
Scope of this article
The examples illustrate structure. They do not assign sessions to a level or validate an individual pace.