MyTrainPal - AI Assistant connected to Intervals

[Krzysztof]

Hi everyone,

I had some spare time over the weekend, so I built an alternative to the current AI Coaching platforms (I couldn’t find one that satisfied me 100%).

What’s different? I took a mobile-first approach, keeping the interface and interactions as simple as possible. I’m a huge believer that the best way to operate on data is a natural language chat window. I’ve made that the central interaction point—you use it to update your goals, log data, and retrieve insights.

For example, there is no separate screen for “injuries.” You just tell the AI you have one, it remembers, and it adjusts your plan. This allowed me to simplify the UI significantly compared to other apps.

Current Status:

• Web: Available now via browser.
• Mobile: I have working native versions for iOS and Android ready (with HealthKit synchronization support), but they aren’t published yet.

Pricing & The Future: Currently, it’s free. I’ve only capped the number of messages to prevent a surprise API bill.

I honestly don’t think it’s possible to monetize simple AI wrappers via subscriptions anymore. I’m considering making this open source (after some code cleanup). This would allow power users to host it themselves and use their own LLM API keys, effectively skipping the middleman.

However, that gates the app from casual users who need a simpler App Store experience. I haven’t figured out how to publish a hosted version without incurring too much cost yet.

A note for test users: Workouts won’t be automatically exported to intervals, as I didn’t want to pollute your calendars. However, there is an option on every workout page to manually export the session if you wish. (UPDATE: As people got confused and messaged me why their workouts are not uploaded to Intervals, it now sets auto-sync ON by default, can be configured in Settings → Connections)

App is available here: https://mytrainpal.app
I’d love your feedback!

Cheers

[Mimmolucio]

Hi. Thank you for letting us test it.
Looks very promising - i like it very much.
One thing: I can’t get Wellness-Data to sync from Intervals.icu (HRV and sleep data). Completed activities do sync.
I have a Garmin that syncs this data to Intervals.icu

[Krzysztof]

@Mimmolucio thanks for the feedback!

There was indeed a bug in Welness-Data sync, but it should be fixed now. Please check and let me know if there are any more issues. Also thanks to @David app now supports oAuth, if you use it you need to enable reading wellness data for this to work.

[Mimmolucio]

It works!
Btw: had a few conversations with your bot - very impressed with the results so far.
If you want me to test some specific features, just let me know - I’d be happy to help

[Krzysztof]

Wonderful, I would be more than grateful if you could help me test the “Plan” feature. Bot when prompted for plan creation should walk you through the details and create the plan with specific blueprint (plan strategy, for instance 80/20). Then it should schedule workouts following that plan and the goal.

I have also a branch that has automatic synchronization of this Plan to the Intervals New Plan feature, but I could only rely on API documentation and I don’t have any means to test it. Although, it would be awesome if AI could read and update your plan in intervals so I’ll definitely work on making that happen.

For now it would be great if you could take a look at this feature inside MyTrainPal. Appreciate your help!

[Mimmolucio]

Will do! I will let you know how it went.

[Mimmolucio]

Tried it now.
Works really well. Tailored to my needs: I told the bot in an earlier conversation that I had the flu last week and don’t fee too strong at the moment. It created a plan with the first 2 weeks focused on frequency and not on duration as to not overtax my immunesystem - top notch!
It is a long term plan with an ultramarathon in 12 months, currently tackling ADS with the MAF-Method. The created plan was a good amount of weeks with just base building, including tips and advices to build a strong engine. And then some mountain specific workouts - i hadn’t studied it in detail, but the first look is very promising!

[Mimmolucio]

[Krzysztof]

Thanks for sharing these conversations, looks like it was able to correctly connect your data and come up with the plan that looks convincing. Let me know in private message what email you used to log in to the app, I can give you more credits or enable more powerful model if you wish to continue testing it.

[Mimmolucio]

Thank you, that is very nice of you. But you don’t need to.
I’m always happy to help someone who is building cool things. I keep using it for now, it looks very useful! If you have any other inquiries, you can p.m. me anytime - as long as my schedule allows I’ll help

[Krzysztof]

I think that’s all in terms of new features for now, I wrapped up MVP and I need to take care of other things now.
I’m glad you find it useful, if you encounter any bugs/issues please let me know. I can take care of it when I find some time.

[Krzysztof]

Hi everyone,

Just wanted to let everyone know that iOS version of MyTrainPal was officially released to the iOS AppStore and can be downloaded here: ‎MyTrainPal App - App Store

With the app you can receive push notifications to your phone and connect to Apple Health for collection of metrics like HRV or RHR.

I believe it’s the most convenient way available right now to be able to analyze your training data with AI. Below I’m attaching few screenshots.

Hope you’ll enjoy using iOS and Web app.

Please report any bugs so we can make the AI coaching better and more accessible to everyone.

Cheers,
Krzysztof

[Krzysztof]

Hi again,

I wanted to share with you quite significant update that was released this morning. Our AI chat now uses a unified data pipeline for both analysis and visualization.

That means the chart you see in chat is built from the exact same aggregated dataset the AI uses to make its assumptions and recommendations.

No more “black box” summaries.
No mismatch between what the AI says and what the graph shows.
Just one source of truth, visible in context.

In the screenshot, you can see this in action:

• ai runs tool with the analysis
• the assistant explains the interval comparison
• inline charts display the same power/HR traces used for that explanation

This makes recommendations easier to trust, easier to verify, and much easier to act on during training review.

[Krzysztof]

AI Coach update: richer metrics, better-grounded answers

I’ve extended the MyTrainPal data pipeline with new training metrics, so AI Coach can reason on a broader and more complete performance picture.

Now you can ask natural questions like:
“Am I training with the right intensity balance?”

And instead of a generic response, AI Coach will:

• ground the answer in your training methodology (e.g. Norwegian Threshold principles),
• use your real HR/power distribution and recent load context,
• visualize the evidence directly in chat (like the zone distribution chart shown here).

[Krzysztof]

Huge thanks to all testers for the feedback. It directly shaped the following feature:

I’ve added a dedicated Week-by-Week Plan chart for:

• Load
• Duration
• Distance

You can now track targets vs actuals across weeks in one place, with clearer visibility into base/build/peak/taper/recovery flow.

I also extended the AI agent data plane to use these weekly metrics directly.
So when you ask natural questions like “What is my planned load for next week?”, AI Coach can answer with more precision, grounded in your real plan structure and current progression.

In practice, this means:

• more accurate weekly load interpretation,
• better workout scheduling decisions,
• and chart-backed answers you can verify instantly in chat.

The screenshots show both sides of this upgrade:

1. the new week-by-week planning view, dotted line represents the estimated planned load/distance/duration
2. and AI Coach using that same data to explain next-week training load in context.

The Web version already supports this new feature, iOS version will need one more day for the AppStore Review to be completed.

[Sjedwardz]

Hi - I’ve been playing with it over the last few days and very impressed with what you have created.

However, chatting with the AI burns through those 200 tokens pretty quickly? Are there any plans to allow us to use our own API keys as I’ve nearly used my allowance already!

[Krzysztof]

Hi @Sjedwardz , thanks so much, really glad you’re finding it useful!

I’m still figuring out the direction for the app, until then there’s a contact email displayed if you reach the limit — please message me there and I’ll reset your usage. Sorry for the inconvenience, running AI isn’t cheap and I need to keep costs in check for now!

One thing worth noting on the API key idea — since the AI agent runs server-side, your key would need to be stored on my server anyway. Curious which you’d actually prefer: trusting me with your API key, or paying a subscription fee that would cover the AI cost?

[DGCom]

I decided to try your app… got some issues:

1. No Android app yet
2. Once you login to the web app, there are no links to mobile apps in UI
3. Trainings-Activities - does not load, but system has data as far as I can see on Progress page
4. Fitness - readiness - Coach Insight does not work claiming it does not have wellness data, but I can see all body and metrics data with history

[Krzysztof]

Hi @DGCom , thanks for checking out the app!

1. Android app will be released soon, I postponed it to not have to manage too many ecosystems at once as people are still testing it and changes are frequent.
2. I’ll think about adding those links. On iOS there’s a standard mechanism that will display badge on top of the page with link to the App. I need to check how that works on Android.
3. Probably some caching issue, I do a lot of caching on the client side to make the experience as smooth as possible, but sometimes things might need a moment to update.
4. Also a caching issue, I’ll update the code to display loading state instead of an outdated message, thanks for pointing that out.

Feedback like this is very valuable for me, so thanks a lot for it. Let me know please if you find any more problems and I’ll make sure to patch it.

[Sjedwardz]

Hi @Krzysztof You raise an interesting point about storing API key. I do use a few apps that have this capability, but I guess as they are more established companies, trust is a bit less of a concern. I think you can put a cap on each API key so you don’t run up a large bill but will need to check
Is it Gemini that you use?

I suppose the decision would depend on the cost of a subscription.