What data comes in
- ·Planned workouts (structured intervals, target TSS)
- ·CTL / ATL / TSB (fitness / fatigue / form)
- ·Form zones (recovered, fresh, neutral, fatigued, overreaching)
- ·Ramp rate
What Intervals.icu is good at
Fitness tracking over time. Quantifying fatigue and form. Structured workout plans. Intervals.icu is the most comprehensive free training analytics platform in endurance sports. If you care about your numbers, you’re probably already using it.
What it misses
Subjective readiness. Sleep quality. Recovery signals. Whether your body matches what the numbers predict. Life stress. TSB says you’re overreaching — but do you feel overreached? That’s the question Intervals can’t answer.
How Rudder uses it
Intervals.icu feeds the Load channel. Rudder looks at:
- ·TSB for form-based conflict detection
- ·Ramp rate — over 7 CTL/week triggers aggressive loading warnings
- ·Planned workouts pre-populate the plan card with structured interval details
- ·Form zone disagreements with subjective feel
When TSB says overreaching but you feel great, Rudder detects the conflict and resolves it. The numbers are one input. Your body is another. Rudder weighs both.
Best for
Data-driven athletes who already use Intervals.icu and want their form metrics to connect to a daily decision.
Example decision
TSB is -25 (overreaching zone). Ramp rate 8.2 CTL/week. But you feel good and slept 8 hours.
Rudder recommends GO WITH LIMITS — your body is handling the load, but cap today’s session. Don’t add more fatigue to an already aggressive block.
Frequently asked
- What does the Intervals.icu integration provide?
- Full OAuth connection. Rudder reads your CTL, ATL, TSB (fitness, fatigue, form), planned workouts, and wellness data. This is the most complete data source we support.
- Do I need both Intervals.icu and Strava?
- You can use either. If you have Intervals.icu connected, Rudder uses its fitness metrics (more accurate). If not, Rudder calculates fitness from Strava activity data.
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