With FTP set to 250 W, our calculator shows Zone 2 from 138 to 187 W. Whole-watt boundaries are displayed without gaps or overlaps.
A common language for effort
Andrew Coggan's seven-level framework covers recovery, endurance, tempo, threshold, VO₂max, anaerobic capacity and neuromuscular power. This calculator uses upper references of 55, 75, 90, 105, 120 and 150% of FTP. They describe targets rather than proving that a particular adaptation starts at a specific wattage.
Neuromuscular work concerns very short efforts, where a simple percentage of FTP poorly describes individual ability. Percentages cannot replace instructions appropriate to the duration of an effort and the rider's characteristics.
Why calculators can show different boundaries
Common charts often show endurance as 56–75% using rounded percentages. Multiplying those intervals and then rounding can leave some watts without a zone. Our continuous display assigns each integer watt to one range: the next range starts one watt above the previous range's upper limit.
At 250 W FTP, 55% is 137.5 W. Recovery ends at 137 whole watts; endurance starts at 138 W and ends at 187 W. This display convention does not claim to describe your physiology to the nearest watt. Check your head unit's selected system too: devices do not all use identical zones.
Use Zone 2 without chasing its upper limit
For an easy ride, choose a power that keeps the effort comfortable as the session continues. The upper boundary is not a mandatory target. Terrain, heat, duration and fatigue can change how the same power feels.
An easy ride after a demanding day should not become a test of endurance. If staying inside the range requires constant strain, slow down and reassess the context. Perceived effort complements the number; a power meter does not make it irrelevant.
When should you recalculate?
Recalculate after adopting a new FTP supported by comparable evidence. Avoid changing settings after every isolated estimate. In EndurTrack, estimated FTP is a reference to review; configured FTP remains the value selected by the athlete.
To connect zones with your schedule, use the training week generator or your account. A table of watts cannot decide session frequency, duration or whether a rest day would be more useful.
Common questions
Does Zone 2 mean the same thing everywhere?
No. A three-zone physiological model and a seven-zone power model use the same number for different categories. Check which system is being discussed.
Can I use these percentages for heart-rate zones?
No. Do not apply FTP percentages to maximum heart rate. The signal and the methods used to define the ranges are different.
Sources and editorial approach
The example weeks are educational EndurTrack proposals, not protocols validated for every individual. The sources below explain the principles and their limitations.
Read the EndurTrack method →