Glossary
The acronyms you see in the panel, explained without hedging. For each: what it means, how to read the values, and what to do about them.
HRV
heart rate variability
The variation in time between consecutive heartbeats — an indirect indicator of nervous-system readiness.
Readiness score
readiness indicator
A single number combining sleep, how you feel, resting heart rate and HRV — the answer to whether today is a day for hard training.
RPE
rate of perceived exertion
Your own rating of how hard an effort was, on a 1-10 scale — the simplest and most universal measure of training load.
RIR
reps in reserve
How many more reps you could have done at the end of a set — a measure of how close you were to failure.
FTP
functional threshold power
The power in watts you can hold for roughly an hour — the reference point for every cycling zone.
CTL
chronic training load
A 42-day exponentially weighted average of training load — a measure of the fitness you have built.
TSB
training stress balance, freshness
The difference between fitness and fatigue (CTL minus ATL) — an indicator of how rested you are today.
Zone 2
low-intensity aerobic training
The intensity at which you can hold a conversation — the foundation of endurance volume in every sport.