Private beta · Invite only · Spring 2027
Your training data isn't telling you anything.
You have four years of runs, a heart-rate zone chart and a fitness curve. None of it answers the only question that matters four months out: am I on track for my goal race?
Bib is a coach that reads your Strava, your watch and Apple Health together. Every week it tells you where you stand and the marathon you could run today. Every day it turns that into your session, grades the run once you're home, and adjusts the plan with you when the week doesn't go to plan.
- 11
- past races tested
- 3.1%
- average miss
- 10 of 11
- inside its band
Bib opens to a small group of early adopters in spring 2027 — tell us a little about how you run and we'll write when your spot is ready.
Apply for the betaAlready invited? Sign in with Google, Apple or your email link. No password, no card.
Tuesday's 8.1 — your best efficiency of the block.
Seven weeks on plan and the projection closing a minute a week.
Coach: Saturday's 12 is the week's real test. Keep today under 141 and arrive fresh for it.
You're already doing something extraordinary.
Only a small fraction of people will ever complete a half marathon.
Even fewer will cross the finish line of a marathon.
And among marathon finishers, only about 1 in 9 runs fast enough to meet the Boston Marathon qualifying standard.
Each finish line puts you in increasingly rare company.
You've run a marathon. Now you're chasing a mark achieved by roughly 11% of marathon finishers.
Mile 13 · California International Marathon
The only question that matters is whether you'll be ready for this.
The math
Three numbers, and no black box behind them.
You already know what a fitness curve is worth. These are the three we compute, exactly how we compute them, and what each one can't tell you.
Your FIT number
Every run, at any heart rate, says how fast you are at one reference heart rate once heat, hills and duration are accounted for. Restated as a marathon time and blended with your latest race, it is the one number your Standing measures against — and it moves only when your fitness does.
It grew out of the efficiency factor (speed per heartbeat), which still runs underneath. A hot week or a hilly route can move it a minute or two, which is why the Standing reads it by the week, not the day.
Load ratio
Whether this week is a sensible step up from the last month. Under 0.8 you're resting or detraining; up to 1.3 is a build your body absorbs; past 1.5 is a spike. Between them is where adaptation actually happens.
It's a guardrail, not a prediction. The coach reads it before it suggests what next week should hold.
Race projection
Your FIT number blended with your recent races, calibrated on how your own past races actually went, then priced on the course you'll run — its hills, and how your last 10K tends to fade. Shown against the time you're chasing.
Every forecast carries a 90% band, and a thin season gives a wide one. Tested against eleven of our founder's past races, it missed by 3.1% on average.
The coach
The numbers say where you stand. The coach tells you what to do about it.
Bib writes a plan for your race from the miles you run now, then walks it with you — through the bad night's sleep, the tight hamstring and the Saturday that won't happen.
- 06:00 · The morning brief
Your sleep, soreness and recovery shape the day’s session, its heart-rate target and what to eat around it.
- Before the run
Hard sessions explained in plain words: the effort to hold and the signal to stop, with more care for a masters runner or a sore spot. Strides are 80–85% of top speed, never a sprint.
- Minutes after
The run graded row by row against the plan, then a short read on what went well, what drifted and what it means for tomorrow.
- Any time · Ask the coach
A coach with your day, your week, your goal and your own notes in front of it — one that remembers what you told it last week.
Hamstring's tight after Tuesday's 8. Should I still run Saturday's 12?
Tuesday held under 141 the whole way, so this reads as tightness, not fatigue. Keep tomorrow's 7 easy and see how it answers on Friday.
If it's still talking to you, make Saturday 10. The long run is the one session this week worth protecting — shortening it beats skipping it.
The long run is a key session, so its miles stay off the other days. Week 38 → 36 mi.
The plan moves with you
An easier day when you need one
When sleep, resting heart rate or a sore spot says today’s session will cost more than it gives, the coach offers the easier version. One tap takes it; one tap keeps the plan.
Change the week by asking
Tell the coach Thursday won’t happen. It works out where the miles can go without touching a key session, shows you the new week, and changes nothing until you apply it.
A review at every block
At the end of each block the coach reads how it went against the forecast and proposes the next: hold, build or ease off. You decide.
Every run is graded before the coach writes a word, and it may only quote what Bib computed from your data. A figure that isn't in your numbers never reaches you.
Who it's for
Built for the runner with a job, a family and a goal.
Not the elite in the front pack. The rest of us — chasing a standard, a best, or a finish line, with forty minutes on a Tuesday and one long run a week. The preparation should be the simple part: run what the plan says, let one word a week tell you whether it's working, and have a coach to ask on the Tuesday the plan doesn't fit your life.
Connections
Keep Strava. Keep your watch. Log only what you want to.
Bib doesn't want to be your training log. Strava is a good one and you already use it — we read from it, we don't replace it. Connect the watch you wear — Garmin today, Coros and Polar next — and the recovery numbers and the lifts arrive on their own. You never have to enter a workout by hand; a note after a run, or a minute on how you slept, is there if you want the coach to know.
Nothing is posted to Strava, and nothing is shared. The only things Bib writes are the ones you ask for: your sessions to your watch, your meals to Health. Disconnect and your history comes with you.
Find out on a Tuesday, not on race day.
Private beta opens in spring 2027, one training block at a time, to the early adopters on this list. Tell us a little about how you run.