Estimates & limitations
Physiology estimates
Physiology estimates are not validated personal physiological monitors, ISO PHS, a medical scan or measured body temperatures. Missing profile and workload inputs use explicit starter assumptions stored with each forecast. Peak heart rate differs from session-average heart rate. Estimated effort describes the end of a working interval, not retrospective session effort.
Planned cooling scenarios
Cooling comparisons use an estimate of body heat removed while a device is held. This is not a verified Kühler rating, electrical input power or hot-side dissipation. Planned contact remains within rest. Small differences may be similar at displayed precision. Physiological comparisons and performance comparisons are calculated separately; modeled temperature change is never converted into extra repetitions.
What the estimates are
Heat load is a 0 to 100 planning index built from the session and conditions you enter. Performance forecast is a numerical projection for a specific measurable task, based on preliminary testing and stated model assumptions. Both are estimates, not measurements.
What they are not
Heat load is not a body-temperature reading, an illness probability, or a clearance to train. A lower score is not a guarantee of safety. The performance forecast is not a promised improvement, and it applies only to the task you selected, not your whole workout or your sport.
Where they come from
The forecast starts from a small set of preliminary, dated cooling test sessions and adjusts for the kind of task, how hard the working sets are and how long you plan to hold Kühler within each rest. Longer holding adds progressively less, the effect levels off at about two minutes, and holding is never assumed to extend your rest. This duration relationship is a modeling assumption that testing will refine, not a measured finding. For a whole-workout projection, only the comparable working sets you mark as covered by cooling carry the response; the rest of the workout is assumed unchanged. When you log comparable sessions with and without Kühler, your own results gradually inform your personal projection. The exact calculation and reference data stay on our servers.
Predictions versus observations
A forecast describes what the model expects before the session. An observation is what you recorded afterward. A single good or bad session does not prove or disprove a cooling effect; rest, pacing, adaptation and conditions all contribute. Look for a consistent pattern across similar sessions.
Your part
Confirm current conditions each session, follow any heat rule that applies to you, and stop and get help if you feel unwell. Guidance and forecasts are estimates, not medical advice. Results vary, and your result may be lower, zero or negative.
These limits are part of the App Terms of Use. How your data is handled is described in the Privacy Notice.
Curious how cooling fits into training? Read the short lessons.