Connect IQ Data Field

Manage Your Anaerobic Matches.

W' Balance is a real-time anaerobic energy tank indicator designed for Garmin bike computers. It models the instantaneous depletion and exponential recovery of your glycolytic capacity (W') relative to your Critical Power (CP), letting you see exactly how much battery you have left before blowing up.

Anaerobic Reserve (W' Bal)

78% Remaining
Capacity Pool: 22.0 kJ W' Bal: 17.1 kJ Critical Power: 330 W

Optimized Pacing Metrics

Know exactly when to burn a match and how long it will take to recover.

Real-Time Depletion

Whenever you power above your Critical Power (CP), the app integrates the cumulative work done above threshold to drain the W' tank in real-time.

Exponential Recharge

When you drop back below CP, the app runs an exponential recharge model, tracking how muscle perfusion and recovery power replenish your tank.

FIT File Integration

Automatically writes your dynamic W' Balance directly into your activity FIT file for advanced post-ride analytical mapping on Intervals.icu.

The Integral of Work Above CP

Critical Power (CP) represents the highest constant power output you can maintain without catastrophic accumulation of fatiguing metabolites. The total capacity pool (W') represents the finite amount of work you can perform above CP before absolute exhaustion occurs.

This data field calculates your dynamic W' balance using Skiba's integral model. By configuring your exact CP (W) and W' (kJ), the algorithm dynamically computes the depletion and recharge cycle, allowing you to survive race-defining climbs and time trial pacing perfectly.

Cross-referencing this anaerobic battery with local muscle oxygenation (SmO₂) via SmO2Graph provides the ultimate window into peripheral extraction vs autonomic metabolic fatigue.

Configuration Checklist

  1. Determine your **Critical Power** (e.g. 330W) and **W' capacity pool** (e.g. 22.0 kJ) from your power-duration curve.
  2. Open the Garmin Connect app on your phone.
  3. Select **Wprime Datafield Settings**.
  4. Enter your exact Critical Power (CP) and W' pool values.
  5. Add the data field to your primary Garmin activity screen.