Rider model
The central representation Gritmo builds from a rider’s evidence and uses across analysis, course planning, and training.
The Profile explains what the rider model means; it is not a second model.
Gritmo reference
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Gritmo Glossary
The canonical public meanings of the terms Gritmo uses to describe riders, evidence, and training.
One concept should have one public name and one stable meaning. Technical implementation language stays out unless it changes how an estimate should be understood.
01
Rider model
Evidence
Observed information that supports or changes the rider model.
Evidence may come from rides, power bests, files, connected providers, or values entered by the rider.
Power bests
The highest credible average power a rider has produced for a specific duration.
Power bests are evidence. They are not a separate rider model.
Observed
A value directly supported by recorded or rider-provided evidence.
Observed efforts remain points; Gritmo does not connect sparse points and call the result observed.
Modeled
An estimate produced by applying a defined relationship to the available evidence.
A modeled value is useful when its evidence, scope, and limits remain visible.
Confidence
How strongly the available evidence supports an estimate.
Confidence describes the estimate, not the ability or value of the rider.
02
Physiology
CP asks: at what power does hard riding start pushing you toward a slowdown? W′ asks: once you ride above that power, how much work can you do before you have to back off?
Two riders can both have a CP of 280 W. At 320 W, both are riding 40 W above CP. The rider with more W′ can keep that move going longer.
Same CP. Different ability above it. That difference helps shape the rider profile: more above-CP power can support a punchier profile, while high sustained power relative to body weight supports a climbing profile. Gritmo also considers short power, Durability, and Repeatability.
Critical power (CP)
CP is where hard riding changes. Below CP, you can hold a hard rhythm. Above it, the effort keeps getting harder until you have to slow down.
The modeled boundary between efforts the body can stabilize and efforts where fatigue keeps accumulating.
In practice: For example, if your CP is 280 W, you can hold a hard rhythm at 270 W. At 320 W, fatigue keeps building and the extra 40 W draws on W′ until you have to back off.
Model limit: CP is not exactly FTP, 60-minute power, or a promise of indefinitely sustainable power.
W′ — work above CP
W′ estimates how much work you can do above CP before you have to slow down.
The model’s estimate of the finite work you can perform above CP before power must fall.
In practice: For example, if CP is 280 W and you attack at 320 W, the extra 40 W draws on W′. A harder attack uses W′ faster; riding below CP lets Gritmo estimate recovery.
Model limit: W′ is not a literal tank, a single energy store, or a direct measurement of your remaining physiology.
Modeled W′ balance
An estimate of how much above-CP work capacity remains as work and recovery unfold.
W′ balance is calculated from the rider model and power trace. It is not a direct measurement of remaining physiology.
Durability
Ability to preserve performance after accumulated fatigue.
Without relevant late-Ride evidence, Durability is unknown—not weak.
Repeatability
Ability to reproduce hard efforts.
A large W′ does not automatically imply strong Repeatability.
03
Product and training
Profile
The interpretation of what the rider model currently means about the rider.
Profile is not another name for Account and not a second rider model.
Ride
One recorded cycling session.
Activity remains valid internal or provider language, but the cycling product calls it a Ride.
Course
A saved or rideable path used for planning, following, or trainer execution.
Route may remain an internal geometry term. Segment is reserved for a measured portion of a Course.
Strategy
A rider-specific plan for distributing effort across a Course.
Strategy describes the planned effort, not the Course geometry itself.
Training target
The rider quality or adaptation that training is intended to develop.
A Training target describes what should improve; a Workout method describes how.
Workout method
The session structure or intensity used to pursue a Training target.
Sweet Spot, Threshold, and Microbursts are methods—not rider adaptations.