[Tool] PacePartner.app — an AI coach that reads your Intervals.icu data and adapts your plan on the fly

AI Tools
1

Hey all,

Long-time Intervals.icu user here.

I’ve been using Intervals for years and it’s honestly the best training dashboard I’ve found. It gives you everything — fitness, fatigue, power curves, HRV trends — and gets out of your way.

But I kept running into the same friction:

I don’t want a full-time coach.
I don’t want to hand over control.
I don’t want to pay $200/month.

What I do want is something that already understands my data and can help me adapt when real life gets in the way.

Travel week.
Bad sleep.
Work stress spike.
Missed session.

In those moments, I’d stare at my CTL/ATL, HRV, and planned workouts and think:

“Is this 2×20 threshold still a good idea… or am I about to dig a hole?”

So I built something for that exact gap.

What I Built

It’s called PacePartner.

It connects directly to your Intervals.icu account (OAuth — no API keys or weird setup), reads your training data, and acts like a lightweight assistant that already knows your numbers.

Here’s what it does:

  • Daily readiness summary
    It reads your overnight HRV, ATL/CTL, recent load, and fatigue and gives a plain-English snapshot of where you stand.
  • Conversational adjustments
    You can ask:
    • “I only have 45 minutes today — what should I do?”
    • “My legs feel cooked. Swap tomorrow?”
    • “I missed yesterday. How do I rebalance the week?”And it answers based on your data — not generic templates.
  • Structured workout generation
    It builds proper zone-based sessions and pushes them straight into your Intervals calendar. No copy/paste.
  • Race-aware planning
    It reads your A/B/C events and builds a sensible build → peak → taper structure around them.
  • Load management nudges
    If stress is creeping up or recovery looks off, it flags it before you overcook yourself.

The key thing:
You’re still in control. Your Intervals setup doesn’t change. This just makes adapting your plan faster and less mentally heavy.

Why I’m Posting Here

This was built specifically for Intervals users — people who like data, don’t want hand-holding, and don’t want to give up autonomy.

There’s a free trial (no credit card required).

If you’re curious:
:backhand_index_pointing_right: https://pacepartner.app

I’d genuinely love feedback from this community — especially the skeptics. If there’s something it should do (or absolutely shouldn’t), I want to hear it.

Thanks for reading :folded_hands:

2

Small PacePartner update: we’ve just shipped a release focused on smoother access and fewer support headaches.

What’s new:

  • Google sign-in/sign-up is now live
  • login is clearer, with separate Google and magic link options
  • auth/session handling is more reliable
  • there’s now an in-app support form in the dashboard
  • /help includes a direct support link
  • daily Telegram messages are less error-prone for unlinked users

A lot of this release was about removing friction around onboarding, login, and getting help when something breaks.

If you’re using PacePartner with Intervals.icu and notice anything off, send it through the new support flow. Feedback on the integration and coaching experience is always useful.

3

Small PacePartner update for anyone here who likes practical decision tools more than generic AI chat.

I’ve put together a public tools page with two free tools that are useful even without signing up:

HRV Training Decision Tool

Race Taper Planner

The idea with both is to help with two high-friction questions that come up a lot in self-coached training:

  1. Should I actually train today?
    The HRV tool is built around the stuff that usually matters more than a single “readiness score”:
  • symptoms first
  • RHR / HRV trend, not one reading
  • easy pace / heart-rate response
  • recent fatigue, load, sleep, travel, soreness

It gives a practical green / yellow / orange / red decision with the logic shown.

  1. How should I taper for an upcoming race?
    The taper planner builds a taper based on:
  • event duration
  • training load
  • current fatigue
  • health status
  • travel / acclimation context

If you’re connected, the taper can also be exported back into Intervals.

I built these because a lot of training decisions are not really “plan generation” problems, they’re judgment problems:

  • am I good to do threshold today?
  • should this be downgraded?
  • how aggressive should my taper actually be?

Would be glad to hear if these are useful, and also what other focused tools would actually help inside the Intervals workflow.

4

Quick update: Strength Sync is now in beta :flexed_biceps:

Pacepartner

can now pull in your strength work alongside your endurance training, so recommendations and day-to-day plan adjustments reflect your full load — not just bike/run/swim sessions.

This is an early beta, so if you try it, I’d love feedback (especially on data mapping, session detection, and how it affects adaptations).

Currently it’s a beta functionality that can sync with hevy and liftosaur

6

Quick update on what shipped this week.

Since March 15, we’ve made a few customer-facing improvements for athletes using PacePartner with Intervals.icu:

  • Strength support: Hevy and Liftosaur flows are smoother now, with better sync handling and cleaner completion state when strength work is pushed back into your training setup.
  • Planning tools: we added a time-crunched workout adapter for days when real life cuts training short (free for everyone) https://pacepartner.app/tools, and fixed the weekly load graph so it’s more dependable
  • Reliability: workout deletion is safer, and Intervals account linking is more resilient when OAuth returns slightly messy athlete data.

If you’ve tried any of this already, I’d really appreciate hearing what feels better and what still feels rough.

7

Since March 21, we’ve rolled out one of our biggest update waves yet for PacePartner.

Highlights:

  • Foundations for human-in-the-loop coaching (expanded coach experience, onboarding, improved linking/invites, coached tiers)
  • More stable login/session handling (fewer auth loops)
  • Reliability upgrades across Intervals and wellness data
  • UX & accessibility polish across key areas

On a related note:

I’ve been building PacePartner.app as a tool to help athletes adapt their training based on health data and load.

We’ve now started trialing coach functionality, and I’m looking for a few coaches (roughly 2–10 athletes) who’d be interested in testing it and helping shape how this evolves.

If that sounds interesting, feel free to reply here or reach out

8

Hi Intervals.icu community :waving_hand:

I wanted to share what has changed in PacePartner since April 17. Most of this release is about making the Intervals.icu integration more useful day-to-day, especially around workout fueling and reliability.

New: workout fueling plans

PacePartner can now generate practical fueling guidance for planned workouts.

You can enable fueling in settings, add your body weight, choose a gut-training stage, and optionally add sweat-rate data. From that, PacePartner can estimate:

  • carbs per hour
  • fluid per hour
  • sodium per hour
  • pre-workout carb timing
  • post-workout recovery guidance

The goal is not calorie tracking or diet logging. It is specifically performance fueling for training sessions and races.

Fueling plans can be written back to Intervals.icu workouts

When enabled, fueling guidance can be added directly to Intervals.icu workout descriptions. That means the plan travels with the workout instead of living only in chat.

This now applies across exported plans from the PacePartner tools, including:

  • taper plans
  • missed-workout replans
  • time-crunched workout adaptations

There is also an endpoint for applying a fueling plan to a specific Intervals.icu event.

Daily updates can include fueling reminders

Morning training briefings can now include a compact fueling summary for today’s planned workout when your fueling profile is enabled and complete.

Ask the coach about fueling

You can ask PacePartner fueling questions directly in chat, for example:

  • “How should I fuel tomorrow’s long run?”
  • “What should I eat after my workout?”
  • “How many carbs per hour for this session?”

If there is a matching planned workout, PacePartner will use that session’s duration and intensity to calculate the plan. For recovery questions, it can use your recent completed workout.

Easier setup: sync weight from Intervals.icu

The fueling settings page now has a “Sync from Intervals” button for body weight. PacePartner tries today’s wellness entry, then recent wellness history, then the athlete profile, so you do not have to manually re-enter data if it already exists in Intervals.icu.

Intervals.icu connection fixes

A lot of work went into making the OAuth connection flow more reliable, especially for new web accounts and accounts linking Intervals.icu after signup.

Fixes include:

  • better handling of new-account Intervals.icu linking
  • refreshing stale auth/session cache after OAuth connection
  • linking Supabase web sessions to the correct Intervals.icu athlete record
  • better fallback behavior when the token response already contains the athlete payload

In short: connecting Intervals.icu should be less brittle now.

Free users can always access help and today’s plan

The /help and /today commands now bypass trial and daily chat limits. Even if you are out of AI coach messages, you can still see help text and today’s planned workouts.

Feedback welcome

If you try the fueling feature, I would especially love feedback on:

  • whether the carb/hour ranges feel useful
  • whether the Intervals.icu workout-description format is readable
  • whether you would prefer fueling fields as custom wellness fields, workout text, or both
  • what sports or workout types need better defaults

Thanks as always to the Intervals.icu community — PacePartner is built around making the most of the training data you already keep there.

9

Hi everyone,

I wanted to share a PacePartner update with the main things added since the last update

The biggest new feature is a Race Plan Builder. It uses your connected Intervals.icu history to help build a race-day plan with pacing, fueling, aid-stop notes, route constraints, injury/rules/nutrition notes, and contingencies. You can also upload a GPX file so the plan can account for route distance and elevation. Generated plans are saved so you can come back to them later.

I’ve also added more public planning tools:

  • Missed Workout Replanner: helps decide whether to move, shorten, replace, or skip a missed session. If you’re logged in with Intervals.icu connected, it can prefill likely missed workouts, recent fatigue context, race timing, and the next few days of planned training.

  • Time-Crunched Workout Adapter: turns a planned workout into a shorter session while preserving the main training intent where possible. It can also use Intervals.icu calendar context for logged-in users.

  • Race Taper Planner improvements: better usability and clearer output for taper adjustments.

The coaching side has also improved. PacePartner now fetches Intervals.icu wellness, recent activities, and upcoming calendar data concurrently, which should make chat replies, Telegram replies, and daily updates faster. Calendar mutation handling in chat has been made more robust, so workout updates generated by the coach are parsed and applied more reliably.

Account and login flows have had a lot of cleanup too: Apple sign-in support, email/password signup fixes, better handling of expired Intervals connections, improved session refresh behavior, and clearer GDPR consent handling for new and existing accounts.

For Telegram users, the onboarding/consent flow now uses inline buttons instead of typed commands, and transient polling/network errors are handled more gracefully.

Under the hood, there has been a large database migration/cutover, stronger auth guards, CSRF fixes, better Sentry/PostHog instrumentation, production smoke checks, and several deployment/reliability improvements. The aim there is less visible but important: fewer stale sessions, fewer schema-cache issues, and more reliable connected-coaching behavior.

I’ve also added more public educational content and SEO improvements around training decisions, including a new article on distinguishing productive overload from under-recovery.

As always, feedback from Intervals.icu users is especially useful because the product is built around connected training history and calendar-aware coaching.

10

I subscribed for one month as a trial, but I would like to cancel it. However, it’s not clear whether I actually succeeded or not. How can I tell if it worked?

11

First of all thank you for trying the service I hope you find value in it during the month. I will make sure to update the UI to give clearer feedback of the subscription status.

In your case the subscription was canceled and you will continue to have the pro functionality until the end of the subscription month

1 Like
12

Hey all,

Quick update on PacePartner.

First off, on a personal note: I’m just back from riding the 315km Vätternrundan. Despite spending most of the spring traveling—which, ironically, was the exact scheduling chaos that sparked the idea for PacePartner in the first place—I actually managed to get through the race in decent shape. Having the system adapt my load around my travel days really paid off.

On the development side, I’ve got some solid momentum going. The biggest news is that I’m currently building an iOS companion app. The primary focus right now is seamless syncing: getting your workouts to and from Intervals.icu directly to your Apple Watch and Apple Health.

For the web platform, the main focus lately has been stability, speed, and UI improvements to get out of your way even faster.

Here is what is now live in production:

Smarter Coaching Engine

Upgraded AI Models: The recommendations and workout adaptations based on your Intervals data are noticeably sharper and more context-aware.

Backend Overhaul Refactored the bot engine and scheduler so everything from generating sessions to email processing is faster and more reliable.

Bulletproof Intervals.icu Syncing

Smoother OAuth Flow: I’ve ripped out a lot of the friction when connecting your Intervals account. This includes fixing the annoying Safari mobile cookie-blocking issue.

Plain-English Errors: If a sync or connection fails (access denied, server error, etc.), you now get a clear, actionable message instead of a generic error code.

Parallelized Authentication: Hardening the OAuth flow even further and running backend logging concurrently so the initial connection process feels instantaneous.

Better Onboarding & Billing

Checkout Upgrades Cleaned up the Stripe checkout experience. Upgrading, managing your subscription, or returning from the payment portal is now much smoother.

Under-the-Hood Analytics: Added (privacy-sanitized) activation tracking. This just helps me see exactly where new users are getting stuck during setup so I can fix those bottlenecks faster.

If you haven’t checked it out yet, you can connect your Intervals account and give the upgraded engine a spin here: https://pacepartner.app

1 Like
13

Hey everyone,

I am excited to share the latest improvements to PacePartner that went live on Sep 7th. This release is all about making your experience smoother, more reliable, and more secure.

Your Coaching Just Got Smarter

The AI coaching engine has received a major upgrade with our new reliable coaching decision flow. What does this mean for you? More consistent, transparent, and dependable training recommendations. The system now uses structured policy evaluations to ensure that every piece of advice you receive is based on clear, logical decisions. No more guessing why a recommendation changed—just better, more reliable coaching every day.

Faster, More Responsive Experience

We have significantly improved performance across the platform. You will notice faster load times when connecting to your training platforms and quicker responses when the system fetches your health and training data. Behind the scenes, we have optimized how we talk to Intervals.icu and other services, so you spend less time waiting and more time training.

Rock-Solid Data Sync

Data synchronization is now more reliable than ever.

If you have ever seen a vague error when connecting to Intervals.icu, those days are over. OAuth errors now provide clear, actionable messages, so you know exactly what to do to get back on track.

Your Data, Your Control

We take your privacy seriously. This release includes hardened GDPR deletion processes, ensuring that when you request data removal, it happens completely and reliably. We have also added additional security protections, including origin checks and rate limiting, to keep your data safe and the platform secure.

Built for You

Every change in this release was made with one goal: to make PacePartner work better for you. Whether it is faster performance, more reliable coaching, or smoother data syncing, these improvements directly impact your daily experience.

Try it out and let us know what you think. We are here to help you train smarter, not harder.

Fredrik