RestOrTrain - AI that thinks about your training for iOS (yes, another one...)

I’m aware of the AI coach bloat in here - please skip reading this if you’re not interested in yet another AI tool. At the same time, I genuinely believe we’ve built something exceptional over the last 6 months and it’s worth sharing.

I’m Antoni, one of three people building RestOrTrain. I’m a cyclist, a long-time Intervals.icu user, and an ex-Google Software Engineer. I’m super excited to share that we just integrated Intervals.icu with RestOrTrain - an AI tool to analyze and plan your training. Basically, it’s an AI chat interface with cycling-specific “steroids” (and there are quite a lot of them…).

I am genuinely stressed to finally share this with the Intervals community. I know exactly how high the technical bar is here, but I think we’re ready for the feedback.

RestOrTrain is iOS only. An Android app is coming, but if you aren’t on iOS, this isn’t for you right now. Sorry.

What were our main goals when building RestOrTrain:

  • The AI only interprets. CTL, ATL, TSB, zones, and load distribution (and everything else we can) is all calculated deterministically before the model sees anything. We know the AI’s job is making sense of the numbers, not generating them.
  • We didn’t compromise on the model. We benchmark AI models specifically for cycling coaching quality and use whatever performs best at the time. That costs real money, which is why the full version is paid (there is some free quota, more on that below).
  • The interface is focused and elegant. We avoided complex dashboards and charts that we could never build as well as Intervals.icu already does. The app is just three sections:
    • Chat: The brain and driver where you actually interact.
    • Calendar: To schedule workouts and inspect past activities.
    • Athlete Profile: To store your specific goals, preferences, and baseline data.

What’s integrated with Intervals.icu

RestOrTrain syncs your full activity history, pulls HRV/sleep/RHR/weight data, and can push your planned workouts back to your Intervals.icu calendar.

Huge kudos to David for an incredible API. I’ll skip saying how much higher the quality of the Intervals.icu API is compared to other, large platforms (I see you, Strava).

Some things worth trying in RestOrTrain

  • Ask anything about your activities, like “Review this ride”, “Would you adjust power targets next time I do this session?”, or “What training led to my all-time power PBs? Any patterns?”
  • Compare two similar workouts from different training blocks side by side by attaching them to the chat, like “Compare my performance in these two races.”
  • Build workouts (or entire training plans) by just chatting about your goals, preferences, etc.

Pricing

As mentioned, we don’t want to compromise on the AI to avoid ruining the experience. There’s a free tier with around 10 messages per month - enough to schedule a training week or review a few rides. For unlimited access, it’s $12.99/month (might vary slightly depending on your country).

We see a future where we will allow unlimited free access, but at the moment, that would require us to sacrifice the quality of the AI, which we won’t do right now. We want this to be a premium, high-quality app and want to avoid “AI slop” and hallucinations as much as we can.

In case you’d like to explore the quota beyond the free tier, I created the HI_INTERVALS promo code for a week of unlimited usage (you will have to provide your card, though).

Rough edges

This is a fresh integration from a three-person team. Some things won’t be perfect yet, but we’d rather share and learn from everyone in here.

I’d genuinely love your direct input: what is the app missing, and what isn’t working well yet? If your into AI analyzing your data, please give it a try.

Thanks!

Antoni






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PS. Huge thanks to many Intervals.icu users that already helped shape how RestOrTrain app looks today and for your patience waiting for this integration. Your feedback was invaluable so far!

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Thanks Antoni for detailed description.
I am training with RestOrTrain since January and I am absolutely loving it. Integration to intervals.icu was the last missing piece to have fully integrated solution to my training needs.
I would like to mention couple of unique features which make this application so outstanding compared to other AI based training support solutions I have tested so far.

Chat driven interface: say what you want, the app does it. Excellent!

Automation: no manual numbers entering, no manual data syncing. Just focus on your goals.

Smart AI model: I can discuss all things training related, I can get explanation of chosen training approach, I can get tips and hints related to my training - your decision to use premium model here is correct and this is what I want to pay for. Other apps were much dumber and limited in use, sometimes giving useless output.

I can ask AI for and get reports based on my data - trends, summaries, averages, anything, I do not need to read any graphs to get this information, and if I want it anyway, I can see graphs in intervals.icu.

GPX route analysis, weather forecast, Sleep, RHR, HRV metrics - simply fantastic!

And finally I have got great results from suggested training plan, which means that the knowledge base is set up correctly and the application is working as intended.

So I can only recommend trying out RestOrTrain, maybe it suits your needs.

Good job Antoni and team!

Hello Antoni,
I have check your app and at the first glance, it seems to be very clean.
Has you said, you have targeted not too much numbers, charts, etc given a comprehensive UX.
Just a quick note, the app is not properly labeling warm-up and cooldown rides from Intervals.icu … they are all labeled as commute rides :wink:
Races are not recognized too …
i’ll probably give it a try.
Best regards.

Thank you a lot for the kind words. Glad you already improved with the app! :slightly_smiling_face:

Hi! I wasn’t aware Intervals.icu has a separate category for warm-ups and cool-downs. Will take a look.

RestOrTrain will treat everything that looks oddly short or very low stimulous as commute, which makes sense to a lot of people.

Having info about races in RestOrTrain would make a lot of sense. Will take a look at how we could synchronize this.

Thanks you for the feedback, it means a lot!