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Glossary: Yousuli power, HR, and pace zones

The Yousuli zone definitions for bike, HR, run pace, and swim pace, all anchored to your tested threshold.

What the Hub uses

The Hub uses the Yousuli zone system by default: an 8-band power scheme for bike, an 8-band scheme for run power, a 7-band scheme for run pace, a 5-band scheme for swim pace, and a 5-band scheme for HR.

Phase B adds an alternative for bike power zones: athletes can be set to the classic Coggan 7-zone model instead. The choice is per athlete and is set by the coach (or the admin) on the athlete edit page. See Choosing a bike zone system for who can change it and what it affects.

The article below describes the default Yousuli system. For the Coggan alternative, see Coggan reference.

Bike power zones (anchored to CP or FTP, unified 8-band)

Your bike zones use the bike power anchor: Critical Power (CP) if you have a CP test logged, FTP otherwise. See Zone anchor methodology for the selection rule and why it works that way.

The band definitions are anchor-relative:

Zone % of anchor Use
Zone 1 (Easy / recovery) 0 to 60% Active recovery, warm-up
Zone 2 (Endurance) 60 to 75% Aerobic base
Zone 3a (Mid endurance) 75 to 86% Race-pace endurance, upper aerobic
Zone 3b (Sweet spot) 86 to 96% FTP-building tempo work
Zone 4 (Threshold) 96 to 101% LT / "one-hour max"
Zone 5 (Suprathreshold) requires W' Race-pace surges, 5 to 20 min
Zone 6 (VO₂max) requires W' 3 to 8 minute intervals
Zone 7 (Anaerobic) requires W' Short hard efforts (under 3 min)

The upper bands (5, 6, 7) need W' (anaerobic work capacity) to place their boundaries precisely. W' comes from a CP test. Without W', the dashboard shows those bands as "Need W' data". The lower bands (1 through 4) render correctly regardless.

The time-in-zone stored on every uploaded activity uses the same 8-band Yousuli definitions. Two cumulative buckets are also recorded for race analysis: time above 95% of anchor and time above 100% of anchor.

If you see a prescription written as "60 minutes in 3a with 4 by 8 minutes in 3b", that refers to this band set.

HR zones (anchored to your sport-specific LTHR, 5 zones)

HR zones lag power by 30 to 90 seconds, so HR is smoother but slower to react. The Hub stores a separate LTHR for bike, run, and swim (since each is different) and computes:

Zone Name % of LTHR Use
Z1 Recovery 68 to 82% Recovery, very easy
Z2 Endurance 82 to 89% Aerobic base
Z3 Tempo 89 to 94% Sub-threshold
Z4 Threshold 94 to 100% LT
Z5 VO2 / Max 100 to 110% VO2 and above

Run pace zones (anchored to your run threshold pace, 7 zones)

Note that for pace, faster is a smaller numeric percentage of threshold pace (because pace is measured as time per distance, so faster = less time).

Zone Pace (relative to threshold pace) Use
Easy slower than 1.30 x threshold pace Recovery
Zone 2 1.20 to 1.29 x Aerobic base
Endurance 1.10 to 1.19 x Upper aerobic
Tempo 1.03 to 1.09 x Sub-threshold
Threshold 0.97 to 1.02 x LT
VO2max 0.88 to 0.96 x 3 to 8 minute intervals
Anaerobic faster than 0.87 x Short hard efforts

So if your run threshold pace is 4:00 / km (240 s / km), your Easy zone is anything slower than 5:12 / km, your Threshold band sits around 3:53 to 4:05 / km, and your VO2max band is 3:31 to 3:50 / km.

Swim pace zones (anchored to your CSS, 5 zones)

CSS = critical swim speed (your 30-minute sustainable pace). All bands are anchored to CSS pace in seconds per 100 m.

Zone Pace (relative to CSS pace) Use
Easy slower than 1.12 x CSS pace Recovery, drills
Endurance between CSS+3s and 1.12 x CSS pace Aerobic base
CSS (threshold) CSS pace plus or minus 3 seconds Threshold work
Suprathreshold between 80% of CSS pace and CSS - 3s Race-pace surges
Anaerobic faster than 80% of CSS pace Sprint, neuromuscular

So if your CSS is 1:30 / 100m (90s), CSS-band sits at 1:27 to 1:33, and Anaerobic begins at 1:12 / 100m or faster.

How zones drive prescription

Workouts in the Hub are prescribed in Yousuli zones (e.g. "60 min Zone 2 normal, then 4 x 8 min Threshold"). The actual targets in watts, bpm, or pace are computed from your current sport-specific threshold (CP for bike, LTHR for HR, run threshold pace for run, CSS for swim). When you log a new test, your bands recompute automatically.

Relationship to Coggan (rough map)

If you came from Coggan-style coaching, the rough translation:

The Hub does not display Coggan zone numbers anywhere. The map is provided only to translate prior workout history that was written in Coggan terms.

Last updated May 12, 2026

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