One word, three different numbers
Ask ChatGPT or Claude for a session at threshold and, in a single sport, that means one thing. In triathlon it means three, measured in three units, found by three different tests, and drifting apart at three different rates.
- On the bike it is FTP, in watts, usually from a ramp or a twenty-minute test.
- On the run it is threshold pace, in time per kilometre, usually from a tempo effort or a recent race.
- In the pool it is critical swim speed, in time per hundred metres, usually from a pair of timed swims.
Give it one of those and it will happily build a triathlon week around all three, filling the gaps with whatever the average athlete looks like. It will try and mimic the thresholds across the other two sports to give you a training plan. Far from ideal as most triathletes know they tend to be strong in one discipline and weak in another so averages don’t work/
The three do not decay together
That independence is specific to multisports like triathlon. A single-sport athlete has one number going slowly out of date. A triathlete has three, moving independently, usually because the training load is not evenly split.
Ride most of the winter and your FTP is current while your run threshold is six months stale. Come back to running in spring and the reverse happens. Swim least of the three, as most age-group triathletes do, and critical swim speed is often the oldest figure in the file by a wide margin, sometimes predating the current season entirely.
The effect is not neutral. ChatGPT reasoning from a stale run threshold and a current FTP will under-prescribe the bike or over-prescribe the run, and the plan will still look coherent, because internal consistency is not the same as accuracy. The mechanics of that, and what a single stale anchor does to every percentage after it, are worked through on the cycling side.
Pool pace and open-water pace are not the same claim
The other multisport-specific trap is treating one swim number as universal. Critical swim speed from a pool is a controlled figure: flat water, a wall every twenty-five metres, a black line to follow. Open water removes all three and adds sighting, a wetsuit, chop and other people.
Most triathletes are slower in open water than their pool number implies, and some are faster in a wetsuit. Either way it is a separate measurement, and an assistant handed only a pool figure will pace a race swim from the wrong one.
Constraints decide more of a triathlon week than fitness does
In one sport the limiter is usually how much training you can absorb. In three it is more often logistics. Pool opening hours, whether the bike is on a trainer or outdoors, how long the commute to open water takes, whether Tuesday can hold a hard run when Wednesday is a swim squad: these decide what is possible before physiology gets a say.
ChatGPT and Claude are both good at respecting constraints and terrible at guessing them. Told nothing, either will produce the plan a triathlete with unlimited pool access and a garage full of equipment would follow. Told that you swim Monday and Thursday because that is when the pool is open, it will build a genuinely different and more usable week.
What this means in practice
Before asking ChatGPT or Claude for anything substantial, it needs four things it cannot work out for itself: the three thresholds with the dates they were set, the race you are pointing at and its distance, the sessions you can actually get to, and anything currently limiting you. The rest it can reason about. Those it cannot, and it will not flag their absence.
Connecting a training platform helps with some of this and not all of it. A platform can supply what you did and often a derived threshold, but a derived value is not the same as a tested one, and no activity feed holds your race date or your pool schedule.
Where Athmex fits
Athmex stores the anchors rather than the plan. Bike FTP in watts, run threshold pace per kilometre, critical swim speed per hundred metres, and open-water pace as its own separate value, each recorded with the date it actually applied. Threshold and maximum heart rate sit alongside them, shared across all three sports.
Races and goals are stored per sport, with an A, B or C priority, so a build race in April and the A race in September are not treated as the same thing. Your available days, weekly hours and constraints are stored too, which is the logistics layer an assistant otherwise has to invent.
Two things follow from storing dates rather than just values. When the assistant reads your context it also receives how old each figure is, and it is instructed to say so rather than reason silently from a stale one. And because superseded values are kept rather than overwritten, the swim number from last October is still visible next to the one from June, which is what turns progression into a question you can ask.
What Athmex does not do is hold your sessions. It stores no activity history and does no coaching. Your swims, rides and runs stay with your training platform and reach the assistant through that platform's own connector; Athmex supplies the athlete those sessions belong to.
Common questions
Does an assistant need all three thresholds?
For a full triathlon week, yes, because each sport's sessions are prescribed against its own anchor. For a question about one sport, that sport's number and your constraints are usually enough.
How out of date is too out of date?
That is a training judgement rather than a rule, and it depends on how much you have been doing in that sport. The practical answer is narrower: record when each value was set, so that whatever reads it later can weigh it rather than assume it is current.
Should I give it my zones or my thresholds?
Thresholds, with their dates. Zones are derived from them, so an assistant given the anchors can build zones on whichever model you prefer, and it can tell you when the anchor underneath them went stale.
Does Athmex store a swim or bike PB?
Not as a personal best. Athmex stores personal bests for running distances, and for swimming and cycling it stores the threshold values, critical swim speed, open-water pace and FTP. Past race results are recorded against the event itself rather than as a PB.
Does Athmex analyse my training or build the plan?
No. It stores no activity history and gives no training advice. It supplies the numbers you entered and confirmed; the assistant does the reasoning.