Procedure

1. Establish Baseline Metrics

   • Determine the user's current Critical Power (CP) and Anaerobic Work Capacity (W') using get_user_history.
   • If metrics are outdated (>4 weeks), schedule a 3-minute all-out test (3MT) to recalibrate baseline values.
   • Use compute_hr_zones to align power-based targets with physiological markers if heart rate data is available.

2. Phase 1: Capacity Building (Weeks 1-4)

   • Long-Interval HIIT (2x/week): Create sessions consisting of 3–5 minute intervals at 100% of CP. Aim for 3–5 repetitions with recovery periods that allow for partial W' reconstitution.
   • Sprint Interval Training (1x/week): Create one session of 4–6 repetitions of 30-second "all-out" supramaximal sprints (Wingate-style). Ensure a minimum recovery of 4 minutes between sprints to maximize W' depletion and buffering capacity adaptations.

3. Phase 2: Intensity Progression (Weeks 5-8)

   • Refined Long-Interval HIIT: Increase intensity to 105–110% of CP. Reduce interval duration to 2–3 minutes to maintain total work time while increasing stimulus for $\text{VO}_2\text{max}$.
   • Maintenance SIT: Continue 1x weekly session of 30-second sprints to sustain anaerobic adaptations and muscle oxidative capacity.

4. W' Reserve Management

   • When building workouts, ensure recovery intervals between high-intensity bouts are sufficient to prevent premature exhaustion before the session goal is met.
   • Use the polarized approach to avoid "middle-ground" fatigue by ensuring easy days (if any) remain strictly aerobic and low-intensity.

5. Monitoring and Recalibration

   • Every 3–4 weeks, use plan_week to insert a testing session (3-minute all-out test).
   • Update the user's training targets based on the new CP and W' values derived from the test results.
   • Use predict_race_time to show the user how these physiological gains translate to potential performance outcomes.

6. Constraint Handling

   • If training frequency is limited to 2 sessions per week, prioritize one Long-Interval HIIT session (for CP) and one SIT session (for W').
   • If training frequency allows 3 sessions, utilize two HIIT sessions and one SIT session.