Whether you want to finish or you want a time, Tapir is built to get you there.
The idea
Most training apps write your block on day one and never look at it again. Tapir treats every session you finish as evidence, and revises. A bad night trims tomorrow; a good month moves your paces. The two run on separate clocks, which is what stops one rough Tuesday from demolishing a marathon build.
Finishing and racing are different jobs
Tapir asks which one you are after, and it changes the block rather than the encouragement, because physiologically they are not the same problem. What stops you finishing and what stops you going faster are two different limiters, and the training that moves each one is different.
The limiter is fuel and durability
You have roughly ninety minutes of stored carbohydrate and a musculoskeletal system that has to keep absorbing landings after it runs low. Long runs teach the body to burn more fat at the same pace and spare that glycogen, which is what stops you emptying out late, while easy volume builds the capillaries and mitochondria that make the whole thing possible. Hard sessions appear in small doses, because they make a given pace feel easier, not because you are chasing a number.
The limiter is the pace you can hold
Above your lactate threshold, lactate accumulates faster than you clear it and the clock starts. That threshold is the single biggest lever on race pace and it is highly trainable, so threshold work becomes the spine of the block. VO2 intervals lift the ceiling it sits under, race-pace work turns the target from a number into something your legs recognise, and the taper is counted back from the day so you arrive sharp rather than tired.
Both blocks are built from the same published models, the ones in the table below, pointed at different ends of them. And both are honest in the same way: Tapir tells you in weeks and in minutes what the goal you have picked actually requires, before you commit to it rather than afterwards, and shows what your current fitness predicts today alongside what the block is worth if you run it. Neither number is rounded in your favour.
Who it is for
Everybody, and that is a design constraint rather than a slogan. The same engine plans a first 5K and a sub-three marathon, because the physiology is the same and only the numbers differ.
Start from walking
No base is assumed. Tapir builds one, and will not let you skip it however keen you are.
Get faster properly
Threshold and interval work at paces you have earned, not paces you hope for.
Periodised to the day
Base, build, peak and taper, counted backwards from your race date.
Triathlon, all three sports
Sprint, Olympic, half distance and full distance. Swim sets in metres at your own threshold pace, rides in watts, bricks, and the long ride on the day you actually have three hours for it.
The week is balanced by training load rather than by hours, which is the distinction most age-group plans get wrong. Cycling is where the hours go, so a week split evenly by time is a week dominated by cycling stress; split by load, the bike takes the hours it needs and the running is not what breaks you. How far that tips towards the bike follows the distance, because an Ironman is six hours of riding before a marathon and a sprint is decided on the run.
Your swim threshold and your cycling FTP are estimated to begin with, so nothing makes you test before you can start. Swim a 400 and a 200, or ride twenty minutes hard, and every session is rewritten around your own numbers.
Where the numbers come from
Every pace traces back to published work rather than a house opinion.
| What | Method | Why that one |
|---|---|---|
| Paces | Daniels' VDOT model | Maps one race result onto an oxygen-cost curve and reads every other pace off it, so all your paces move together. |
| Swim paces | Critical swim speed | Two timed swims, a 400 and a 200, and the difference between them gives the pace you could hold for about an hour. The same idea as threshold on land, measured in the one sport where effort and speed part company completely. |
| Bike intensity | Functional threshold power | Watts rather than speed or heart rate. A headwind, a hill and a fresh set of legs all change what a given speed costs you; the power meter does not care, and the zones come off one twenty-minute test. |
| Heart rate zones | Lactate threshold heart rate | Anchored on threshold rather than maximum, because you can measure threshold in a twenty-minute test and measuring a true maximum means an all-out effort nobody should be asked for. |
| Training load | Acute-to-chronic workload ratio | Compares the last week against the last month, which is how you catch someone ramping up faster than they are adapting. |
| Fuelling | Carbohydrate per hour by duration | Guidance for long sessions only. No calorie counting and no deficits. |
Some of that maths is open source. It is textbook, it is more useful in the open, and publishing it means you can check what the app is doing to your training.
It tells you the truth
If your goal time drifts out of reach, Tapir says so while there is still time to do something about it.
It works with no signal
Your plan is generated on your phone and stored there, encrypted. No account required, and we do not need to be online.
Nothing to connect
No account linking, no watch to pair. Record a run or a ride in the app, or log either by hand, and the plan responds to it.
You can stop
Injury, illness, a new baby, a bad month. Stop with no end date and nothing is missed. Come back and the plan is built for whoever comes back.
No weight, no calories
No deficits, no BMI, no weight-loss targeting. It coaches your training and nothing else.
What it will not do
- Count your calories, track your weight, or suggest a deficit.
- Nag you while you are stopped. Pause it and it goes quiet until you come back.
- Guilt you for missing a run. Showing up is the whole game, and Tapir goes quiet when you are injured.
- Sell your data, use it for advertising, or train models on it.
Tapir is a fitness product, not a medical one. Talk to a doctor before starting a plan if you have any reason to think exercise may be unsafe for you, and stop if something hurts.
In review
Tapir is with Apple and Google for review, and will be on the App Store and Google Play shortly. Get in touch if you want to hear when it lands.