Questions runners ask

Absorb works with Strava, and Strava is the only connection it needs. Garmin, COROS, Suunto, Polar and Apple Watch all sync to Strava automatically, so if your runs already appear there, Absorb can read them.

Direct connections to the watch brands are not live yet. Everything Absorb needs is already in what Strava has.

Absorb only asks about runs long enough for fuelling to matter. You set that length yourself when you sign up, and anything shorter is skipped without being counted against you.

If you want to log a short run anyway, you can open it and do so. A run that went fine takes two taps.

Absorb says something on your first logged run, and something worth acting on after about five. The first run gives you where it sat among your conditions. From two runs in the same condition it will name what has coincided, and it says so in careful language, because two runs is two runs.

Below two runs it says nothing at all rather than guessing.

Absorb imports about three years of your running and works out the terrain, the temperature, the climb and how hard each one was, so the picture of what you have been out in starts full rather than empty. That part needs nothing from you.

What it cannot do is know how those runs went. Patterns are built from runs you have marked, so an unmarked run adds to what you have run in and adds nothing to what you have learned. The picture fills from the day you start logging.

Absorb keeps the part you use every week free, and it is not a trial. Logging runs, everything in insights, your race results and retrodiction cost nothing. Planning a race is the paid part: the course, the pacing, the per-stop fuelling and the crew console.

The first 100 members pay £100 a year and keep that price for as long as they stay. After that it is £199 a year, or £20.99 a month. See the full breakdown.

Absorb does not sell, rent or license your data to anyone, and does not use it, or anything derived from it, to train models across users. There is no analytics tool and no tracking in the product: it does not record which pages you open or which features you use.

Three services see a slice each and nothing more. The hosting and database run the service. Open-Meteo receives the time and rough place of a run so the weather can be looked up, and never your name or anything you wrote. Anthropic receives the text of race webpages you ask Absorb to read, and never your runs, your notes or your health data.

Absorb gives you both from inside the app, with no email to anyone. Account settings, Advanced, Download your data builds a single file with your profile, every run and everything derived from it, every note you wrote, your race plans and the patterns worked out from them. Anything stored encrypted is decrypted for you. It asks for your password first, because the file is your whole account.

Deleting the account is the same two taps, with a grace period before anything is removed so you can change your mind.

Absorb does not identify causes, and nothing that reads a finished run can. What it can show is which conditions were present when a race went wrong, and whether those conditions had appeared in your training beforehand.

A race in 30C heat when you had never trained above 22C is an untested condition. That is a useful thing to know and it is not a diagnosis.

Absorb is neither. It is a memory and calibration system, not a nutrition app, a macro tracker, an optimiser or a training plan. It does not count calories, does not build you a meal plan, does not tell you what to eat and does not write your week. It remembers what you did and what went with it.

It is meant to sit alongside a coach, or alongside your own judgement, as a cross-check rather than an authority.

Absorb does not set you a number, and the published range has moved. Guidance for long efforts has clustered around 60 grams an hour for most endurance work, rising to about 90 for long events, and reaching 90 depends on mixing glucose and fructose rather than relying on one source. More recent trials in trained runners have gone higher again, with 120 grams an hour tested over a mountain marathon in athletes who had built up to it over months.

Those are population averages from the published literature and they are not advice from Absorb. The number that matters is the one you have actually run on. Absorb records what you took and what happened afterwards, so that after enough runs you can see which rates you have tested and which you have not.

Absorb is not a medical or dietary service and nothing here is individual nutrition advice.

Absorb cannot tell you why. What it can tell you is that race day combines conditions your training rarely combined: longer, hotter, more climb, an earlier start and a higher effort, all at once. Each one on its own may be familiar and the combination may never have happened.

Whether that is what got you is not something a finished run can answer. What Absorb does is make the combination visible beforehand rather than afterwards, by showing which of race day’s conditions you have runs behind and which you do not.

Absorb calls a condition untested when you have no marked runs in it, so it has nothing to say about that condition. It is a gap in the evidence, not a verdict about you. Plenty of people finish races in conditions they never trained in.

Absorb also tracks how long ago you last tested something, so a condition can move from dialled in, to worth a refresh, to going cold, without anything having gone wrong.

Absorb gives a range, never a single predicted time. The projection is built from runs you have actually done: where your training covers the course the range tightens, and where it does not it widens on purpose. A single figure would read as a promise the app cannot make.

Once you save a target, your plan does show one time per stop, because that is what you run to. The range is still there behind it. Where a race has a cutoff, Absorb reports the chance of not finishing separately rather than folding it into an optimistic time, and it will not show you a finish beyond the cutoff.

Absorb turns your race plan into a shared page for your crew. You generate a short code and send it by link or message. They open it, choose a name and a password, and they are in. No Absorb account, no app to install, nothing to pay.

They see one race: every stop in course order, where to park, arrival windows, cutoffs, drop bags, the forecast at the hour you should reach each stop, and what you need handed over. They see nothing else about you, not your training, your patterns, your other races or your email.

Absorb lets your crew save the whole race page to their phone before the start, so the plan, the stops, the arrival windows and the cutoffs stay readable with no signal at all. That is a deliberate button rather than something that happens by accident.

Reading works offline. Ticking things off and sending messages need signal, and there is no queue that sends them later, so anything logged in a dead spot has to be done again when the signal returns. Your own runner view does not have an offline mode yet.

Absorb was built by one ultra runner in the UK, and it publishes its own misses. The clearest example is retrodiction: it rewinds the engine to the morning of races you have already finished, using only what was known before that start line, and shows you what it would have said. Hits and misses both.

The honest state of it: the constants behind the pacing engine were fitted against a handful of runners, which is a small sample, and the internal audit says so plainly. That is exactly why the founding members matter. A hundred people with real race histories is what turns a model calibrated for a few people into one calibrated for runners.

Absorb has an optional cycle space that is off unless you turn it on, and turning it on is its own separate consent step that names exactly what will be stored. You can use every other part of Absorb without it.

What makes it different is what it refuses to do. Absorb never predicts a phase, never estimates which one you are in, and never adjusts your fuelling or pacing by phase. It records the phases you name, on the dates you give, in your own words, and shows them next to your runs. It is encrypted with its own key, never appears in logs, and one tap erases all of it without touching the rest of your account.

Absorb is not open yet, as of August 2026. Leave an email on the waitlist and you get one message on the day it opens, and one about the founding member places. Nothing else.