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





