Zela IQ · in development
Zela IQ tells you why — and admits it when there is no honest answer.
This run was 12% slower than your usual at this distance. It was 28°C, about 15° above what you normally train in — so this is the conditions rather than your fitness. Efforts in weather like this are worth judging on effort, not on the clock.
That last reading is empty on purpose. The effort was not steady enough to measure drift honestly, so Zela IQ reports nothing rather than a number it cannot defend.
Every verdict arrives with the reasoning and the numbers behind it, in plain English. Not a rating out of a hundred — an explanation you can disagree with.
No population models, no age-group percentiles, no strangers on a leaderboard. Every comparison is against your own history: your paces at that distance, your usual conditions, your normal sleep. “Unusually hot” means something different for a runner in Florida than one in Scotland, and it should.
When a session is too ragged to measure, Zela IQ returns nothing. When the signals disagree about whether you were indoors, it says unknown rather than guessing. When it can tell you wore a dedicated heart-rate sensor but not which kind, it says the first and not the second. Most apps fill those gaps with a confident number. Knowing where the edges are is worth more than an answer that is always available.
Whichever watch you own
Zela IQ reads the .fit files your device already records, so it works
the same whichever brand you train with. Bring an export from any of them — or a Strava
archive spanning every watch you have ever owned — and it merges onto one timeline.
GarminSuuntoCOROSWahooPolarZwiftStrava
And when a new watch reads your resting heart rate a few beats differently from the old one, Zela IQ works the offset out from the days you wore both — so changing device does not masquerade as changing fitness.
Some of what it works out
| Aerobic durability | Whether your heart rate held against your pace — with strict rules about which sessions are even eligible to judge |
|---|---|
| Heart-rate recovery | How fast your heart falls after every hard effort in a session, not once at the end |
| Conditions | Heat and wind for any outdoor session, any brand — including what your body actually experienced, not just what a thermometer said |
| Races | Told apart from training automatically, with the reason shown, and always yours to overrule |
| Real active time | Spots a watch left running after you stopped — and tells you, without ever altering the original recording |
Your data
Your uploads are kept exactly as they arrived. Every metric is derived rather than destructive, so anything can be recomputed from source instead of trusted on faith. Nothing is deleted, and nothing is quietly corrected behind your back.
Zela IQ is in active development, built and tested against real multi-year training histories rather than demo data.