Closed Loop · AI running coach
The training plan that checks its own work.
Closed Loop is an AI running coach for iPhone. It builds your plan to race day, reads what actually happened from your watch and strap, and re-plans every week from reality.
Private beta · iPhone · by invitation through TestFlight

Most training plans are written once — then ignore you.
You miss a run, or you run slow because it was hot and hilly, and the plan carries on as if nothing happened.
Closed Loop closes that loop. It writes a full plan from today to your race day, sends each session to your watch, and then looks at what you actually did. Every completed run is corrected for the climbing and the heat, so a hard, hot, hilly run is scored for what it was really worth. Your heart rate is compared with what the session should have cost, which shows whether you are fitter or more tired than the plan assumed.
Every morning the coach gives you a plain verdict on today's session: do it as planned, change it, or rest, and why. Every evening it looks ahead to tomorrow. Every week the plan is re-checked against your real training, including the days you walked or danced instead of running, and against your goal. If the goal is drifting out of reach, it says so, with the numbers.
It works with the data you already collect: Apple Health and Apple Watch, WHOOP, and Garmin.
Why “Closed Loop”
Plan. Run. Measure. Adjust.
- PlanA full plan to race day.
- RunThe session is on your watch.
- MeasureWhat you did, corrected for hills and heat.
- AdjustNext week is re-planned from reality.
Every run, judged fairly
6:30/km on paper. 5:56/km once the hills are counted.
A 6:30/km run over 299 m of climbing is not a slow run. Closed Loop corrects each run for elevation and heat and shows what it was really worth — 5:56/km in this case. It tells you whether you drifted from the plan or only looked like you did.

A coach that talks to you every day
A plain verdict every morning, tied to your week and your goal.
A short verdict each morning on today's session, in plain language, tied to your week and your goal. A look-ahead each evening. After every run, a review that names one thing you did well and one thing to improve.

The best hour to run
It reads the forecast and your calendar, and tells you when to go.
When it is hot, it adjusts the target pace instead of asking you to chase a number.

A plan built around your race and your week
Pick the race, the date and a target time.
Choose how many days you run and lift, and which day is your long run. You get every week to race day, in phases, with the reason for each session.


Structured sessions on your wrist
Warm-up, intervals and cool-down, already on your watch.
Warm-up, intervals, recoveries and cool-down, with heart-rate or pace targets, sent to Apple Watch. Garmin delivery is in beta.

An honest check on your goal
If the goal is a stretch, it tells you by how much.
Closed Loop estimates your current fitness from your own runs and compares it with your target time. If the goal is a stretch, it tells you by how much, and lets you decide.

Join the private beta
Closed Loop is invitation-only while we test it with a small group of runners. Email us and tell us what you are training for.
enroll@halo-design.netiPhone with iOS 17 or later. Installed through Apple TestFlight. Free during the beta.