Changelog

Updates that affect how you use IcuSync with Claude.

New tools available. To get the latest tools, click the three-dot menu next to IcuSync in your Claude Customize settings and select Refresh tools list, then start a fresh conversation. If that does not work, disconnect and reconnect instead.

3 Jun 2026

  • Added direct Intervals.icu coach access. Coaches who already have coaching relationships on Intervals.icu can now connect their own account via OAuth and access all their coached athletes through Claude with no athlete setup required. Athletes do not need an IcuSync account. The coach connects once, and Claude automatically detects their full coached roster. All 14 tools are available for every coached athlete. This is in addition to the existing IcuSync invite system, which remains unchanged. If you are an existing IcuSync user and already coach athletes on Intervals.icu, you need to reconnect your Intervals.icu account once from your dashboard to activate this. New users connecting after this update will get it automatically.

26 May 2026

  • Claude now checks your current training load and recovery status before recommending or creating a training plan. Get Wellness and Get Fitness are called automatically to assess ATL, CTL, and TSB so that workout prescriptions reflect your actual fatigue state rather than an assumed baseline.
  • Tags are now visible to Claude. Activity tags you apply in intervals.icu (e.g. Z2, Intervals, Threshold) are now returned by get_training_history and get_events, so Claude can filter and analyse your training by tag.

10 May 2026

  • Added push_wellness to write wellness data back to intervals.icu. Claude can now log daily nutrition totals (kcal, carbohydrates, protein, fat) from a food tracking source, subjective scores (fatigue, soreness, mood, motivation, stress on a 1-5 scale), body weight, and daily notes. Only the fields provided are updated. Device-synced data such as HRV, sleep, and resting HR is left untouched.
  • The intervals.icu OAuth connection now requests Wellness Update permission alongside the existing Wellness Read permission. Existing users need to grant this permission before push_wellness will work. You can do this by going to intervals.icu Settings, Apps, finding IcuSync and clicking edit to add the Wellness update permission. Alternatively, reconnect your intervals.icu account from the IcuSync dashboard.

4 May 2026

  • Updated get_wellness to include carbohydrate, protein and fat intake (in grams) alongside the existing kcal field. Data is only populated if the athlete logs food in intervals.icu.

1 May 2026

  • Updated push_workout with day of week validation. If Claude calculates the wrong date for a given day (for example, thinking Monday is May 5 when it is actually May 4) the server catches the mismatch and returns the corrected date so it can be fixed before landing on your calendar.
  • IcuSync now works with ChatGPT following the addition of MCP support in ChatGPT Developer Mode. Reading training data works reliably. Creating structured workouts is supported but Claude remains the more accurate option for that. See the full comparison article for setup details and what to watch for.

23 April 2026

  • Added get_training_summary to aggregate training stats over any date range. Returns total volume, TSS, and calories by sport, power/HR/pace zone distribution with time and percentages, and a week-by-week breakdown. Useful for block reviews, load tracking, and answering questions like “how much Z2 did I do this month”.
  • Weather conditions are now included in get_activity_detail when available. Temperature, feels-like, min/max temp, wind speed, wind gusts, wind direction, and headwind/tailwind percentage.
  • One-click calendar subscription added to the dashboard. Once connected to Intervals.icu, your training calendar appears automatically with buttons to add it directly to Apple Calendar, Google Calendar, or Outlook. No copy-pasting required.
  • Workouts pushed to your calendar via IcuSync are now automatically tagged with "icusync" in Intervals.icu. Custom tags can also be added by asking Claude (e.g. "tag this as marathon block"). To skip tagging entirely, just ask Claude not to add tags.

20 April 2026

  • Added get_extended_metrics to retrieve advanced sensor data aggregated per interval. For cyclists: core body temperature, DFA alpha1 aerobic threshold marker, W’ prime balance (energy reserve), and blood glucose. For runners: ground contact time, vertical oscillation, GCT balance, and vertical ratio. Data availability depends on the athlete’s device and sensor setup.

17 April 2026

  • Intervals.icu connection now uses OAuth. New users connect with one click via the Connect with Intervals.icu button in their dashboard. No API key or Athlete ID entry required. Existing users connected via API key continue to work without any changes. If an existing user disconnects, they reconnect through OAuth. Garmin attribution added to activity data returned to Claude, in line with Garmin brand guidelines.

16 April 2026

  • Added Strava activity detection. Claude now automatically identifies activities sourced via Strava and explains why detailed data may be unavailable, with guidance on how to fix it.

15 April 2026

  • Added coach access, allowing athletes to invite their coach by email from the dashboard. Coaches receive a personal MCP URL and can access their athletes' training data through Claude with no IcuSync account required. Athletes control which tools to grant and can revoke access at any time. One MCP URL covers all athletes who invite the same coach email.

12 April 2026

  • Added get_power_curves to analyse your best power output across key durations for run and ride, including CP and FTP model estimates.

11 April 2026

  • Added get_best_efforts to retrieve your personal bests directly from Intervals.icu across key distances and durations.

8 April 2026

  • Added get_wellness to retrieve daily wellness data including sleep, HRV, resting HR, and weight.

March 2026

  • Launched IcuSync with 8 tools covering training history, activity detail, fitness metrics, athlete profile, calendar events, and workout push, edit and delete.

Have feedback or questions? Join the discussion on the Intervals.icu forum.