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Watt4 vs RestOrTrain
Both are AI cycling coaches you can talk to. RestOrTrain is a phone app that connects to almost every device, reads your sleep and HRV, and changes your plan when you ask. Watt4 is free with no limit on messages and re-plans your week by itself. Looking for a RestOrTrain alternative? Here is where the two differ.
| Watt4 | RestOrTrain | |
|---|---|---|
| Free to use | Watt4Yes: Free, with no limit on coach messages | RestOrTrainPartly: A few coach questions a month are free; unlimited costs $14.99 a month or $134.99 a year (€14.99 or €134.99 in the eurozone) |
| AI coach chat | Watt4Yes: Ask about your training, have it build a session, or have it propose a plan change you approve | RestOrTrainYes: Changes your plan in the chat when you ask; ideas of its own arrive as a proposal |
| Plan adapts by itself | Watt4Yes: Re-plans when a ride differs from the plan, a session is missed, or your week changes | RestOrTrainNo: By design, the plan only changes when you ask the coach |
| Plans around your availability | Watt4Yes: Time per weekday and sessions per week; mark single days off with a reason | RestOrTrainYes: Tell the coach which days and how long you can ride |
| Event goals | Watt4Yes: One event, or another goal: getting faster, an aerobic base, maintaining, recovering; optional W/kg target | RestOrTrainYes: Races on your calendar up to a year out |
| Rides from Garmin, Wahoo, COROS and others | Watt4Partly: From Garmin | RestOrTrainYes: From Garmin, Wahoo, Hammerhead, COROS, Zwift, Rouvy, Intervals.icu and Apple Health |
| Workouts sent to your device | Watt4Yes: To Garmin or Wahoo, with one tap | RestOrTrainYes: Automatically, to Garmin, Wahoo, Hammerhead, COROS, Zwift, Rouvy, Intervals.icu and Apple Watch |
| FTP without testing | Watt4Yes: Estimated from your rides and shown on your Progress page | RestOrTrainYes: Estimated from your rides; the coach uses it, but it isn't shown as a number |
| Training without a power meter | Watt4Yes: Heart-rate targets switch on automatically | RestOrTrainYes: Uses heart rate and how hard it felt |
| Sleep and HRV | Watt4No: No wearable data; today's session eases when fatigue runs high or you tell the coach you're ill | RestOrTrainYes: From Garmin, Apple Health, COROS, WHOOP or Intervals.icu |
| Swimming and triathlon | Watt4No: Cycling and running | RestOrTrainYes: Cycling first, with running and swimming for triathletes |
| Indoor workout player (ERG) | Watt4No: No player of its own; download workouts for Zwift (.zwo) | RestOrTrainNo: No built-in ERG player; workouts go to Zwift, Rouvy or your head unit |
| Works in the browser | Watt4Yes: In any browser, and from your phone's home screen | RestOrTrainNo: No browser version |
| App-store app | Watt4No: Web app only | RestOrTrainYes: iPhone, iPad and Android |
RestOrTrain's details checked on 7 October 2026 against RestOrTrain's website, FAQ and App Store listing. Apps change: check restortrain.com for the latest.
Which one fits you
Watt4 is the better pick if
- you want to message your coach as often as you like, for free
- you want your plan to adjust by itself after a missed or different ride, without asking
- you'd rather use it in a browser
RestOrTrain is the better pick if
- you want your sleep and HRV from a watch or WHOOP to shape your training
- you use COROS, Hammerhead, Rouvy or an Apple Watch and want workouts on them automatically
- you train for triathlon
- you want an app from the App Store or Google Play
Price
RestOrTrain has a free tier with a few coach questions a month. Those questions can build and change your plan, and when they run out your plan stays and keeps reaching your devices. Unlimited questions cost $14.99 a month or $134.99 a year in the US; the App Store charges €14.99 or €134.99 in the eurozone.
Watt4 is free while we are building it, with no limit on how often you message the coach. There is no card to enter.
Who changes the plan
This is the biggest difference in approach. RestOrTrain's plan never moves by itself: the coach changes it when you ask, and it says what changed and why. That is a deliberate choice, and it means you are the one who starts every change.
Watt4 re-plans on its own. When a ride goes harder, shorter or differently than planned, when you miss a session or when your week changes, the coming days are planned again. When you ask the coach for a change, it shows you what it would do to your week, and nothing changes until you approve it.
Devices and recovery data
Here RestOrTrain is ahead. It sends your plan automatically to Garmin, Wahoo, Hammerhead, COROS, Zwift, Rouvy, Intervals.icu and Apple Watch, and it reads sleep, HRV and resting heart rate from Garmin, Apple Health, COROS, WHOOP or Intervals.icu.
Watt4 sends a session to Garmin or Wahoo with one tap, or lets you download it as a Zwift workout file. It doesn't read sleep or HRV: it eases today's session when your fatigue runs high or when you tell the coach you're ill or sore.
FTP and training by heart rate
Both estimate your FTP from the rides you already do, so neither sends you out to test. RestOrTrain's coach uses its estimate without showing it as a number. Watt4 shows its estimate on your Progress page, and you can accept it or enter your own.
Both work without a power meter. RestOrTrain uses heart rate and how hard each ride felt. Watt4 notices you ride without power and switches your targets to heart rate by itself.
Questions
Is Watt4 a free alternative to RestOrTrain?
Yes. Watt4 is free with no limit on coach messages. RestOrTrain's free tier includes a few coach questions a month, and unlimited use costs $14.99 a month or $134.99 a year. RestOrTrain does have things Watt4 doesn't, such as sleep and HRV data, automatic workout sync to more devices, swimming, and phone apps.
Does the plan adapt automatically?
In RestOrTrain, no, and that is by design: the plan changes when you ask the coach. Watt4 re-plans by itself when a ride differs from the plan, a session is missed or your week changes.
Is there a web version?
RestOrTrain has no browser version; it runs on iPhone, iPad and Android. Watt4 is a web app that works in any browser and can be added to your phone's home screen.
Do I need a power meter?
Not for either. RestOrTrain uses heart rate and how hard each ride felt. Watt4 switches your targets to heart rate automatically when you ride without power.
What do I need to switch from RestOrTrain to Watt4?
A Garmin account with your rides on it. Watt4 reads your last three months, estimates your FTP and fitness from them, and plans your first week straight away.
Try Watt4 next to what you use now
Connect your account and Watt4 reads your recent rides, sets your FTP from them and plans your week. Free, no card.
Start freeRestOrTrain is a trademark of its owner. Watt4 is not affiliated with or endorsed by RestOrTrain.