Know Your Numbers

There is no single 'threshold'. A 20-minute test gives FTP20, a ramp gives peak power, several maximal efforts give critical power and W′, a lab gives lactate or ventilatory thresholds — and these agree on the average while disagreeing for one athlete by a whole training zone: critical power and lactate markers correlated at r = 0.81–0.98, yet differed by ±22 to ±52 W for the individual (REF-732, B+). So the question is not which test is right but which number your zones hang on, measured the same way every time. These twenty-three sessions are the tests in the Blocks knowledge base plus what practitioners actually use — coaches' field tests (Friel, Allen–Coggan, the app ramps, the long FTP test), how WorldTour teams look at durability and the weekly fatigue check, and the Norwegian lactate-guided threshold — separately for the bike and for running, each with its protocol and an honest note on how strong the evidence is: what a study validated, and what is coaching convention. References are to entries in the Blocks knowledge base, with their evidence level; the assistant can open any of them.

• —How to read the percentages: bike steps are % of FTP, run steps are % of threshold pace (higher is faster). Maximal efforts are open steps — your watch or trainer gets no target, because the number is what comes out of the effort. Their percentage only draws the chart. On a smart trainer, run every maximal test in resistance or slope mode, never ERG.
• —The warm-up is the same in every bike test on purpose: 15–20 min progressive, 5 min near but below threshold, 5–10 min easy, then start. A below-threshold priming bout ending 10 minutes before a 7-minute effort raised power by 2–3%, while repeated sprints did not (REF-270, B). Runners: easy running plus a few relaxed strides; a warm-up at 60–70% of VO2max helped, one at 80% did not (REF-300, B).
• —Test fresh, after an easy day. After muscle-damaging exercise, sprint and incremental test power fell while time-trial performance held (REF-701, A). A 20-minute effort after four hours of riding came out 2.9% lower in professionals, from −8.5% to +1.1% (REF-196, B) — a rested test does not describe your power late in a long day.
• —When two numbers disagree: for the boundary between hard-but-sustainable and unsustainable, critical power (or critical speed) is the anchor the evidence supports (REF-173, B+). Do not switch markers mid-season — the switch will look like a change in fitness. Prescribe steady threshold work a few percent below CP.
• —Where the evidence is thin, the notes say so: no ramp → FTP factor, no validated 30-minute heart-rate test or 5-km → threshold conversion for runners, no evidence for a retest interval, and almost every validation study is small and male. The protocols are still the best available — run them the same way and the comparison with yourself stays honest.
• —Left out on purpose: the Conconi test — its heart-rate deflection was reproducible in only 6 of 15 runners and absent in 4 (Jones & Doust 1995, outside the base) — and modelled thresholds with no test at all (intervals.icu eFTP, WKO mFTP, Xert), which are useful between tests but read only the maximal efforts you happened to do.
• —No maximal test with illness, fever, chest symptoms or unexplained palpitations. The Max Heart Rate and maximal tests are for healthy, rested athletes.

The sessions