Procedure

1. Assess Environmental Conditions

   • Use web_search or local data to determine the ambient temperature (°F) and dew point (°F) for the user's scheduled running time.
   • Calculate the Total Load Score (Temperature + Dew Point).

2. Determine Primary Adjustment Strategy

   • If Total Load Score $\le 100$: No adjustment needed.
   • If Total Load Score is $101–160$: Apply the Combined Heat Load Method to determine the percentage pace reduction.
     • 101–110: 0.5% slower
     • 111–120: 0.5%–1.0% slower
     • 121–130: 1.0%–2.0% slower
     • 131–140: 2.0%–3.0% slower
     • 141–150: 3.0%–4.5% slower
     • 151–160: 5.0%–8.0% slower
   • If Total Load Score $> 160$: Pivot the workout to Effort-Based (RPE) only.

3. Refine Pace Using Dew Point Thresholds

   • For specific target paces between 60°F and 75°F dew point, apply the linear formula: $\text{Adjusted Pace} = \text{Base Pace} + [(\text{Dew Point} - 60) \times 0.025]$.
   • If dew point is $70^{\circ}\text{F}–75^{\circ}\text{F}$, recommend a 5–12% pace reduction for hard intervals.
   • If dew point is $> 75^{\circ}\text{F}$, instruct the user to ignore GPS pace and use a Rate of Perceived Exertion (RPE) target (e.g., Threshold = 7/10).

4. Update Training Plan

   • Use update_workout to modify the targets for the current session based on the calculated adjustments.
   • If a sustained heatwave is present (multiple days > 150 Total Load), use update_week to reduce total volume by 10–15% and increase rest between hard sessions.

5. Provide Physiological Context

   • Create a note using create_note advising the user on:
     • Strategic timing (pre-sunrise runs to minimize Total Load).
     • Increased electrolyte/sodium intake to support plasma volume.
     • The non-linear nature of performance degradation in extreme conditions.

6. Monitor and Iterate

   • Review session RPE and HR data after the run to calibrate future adjustments, noting that heat stress increases the recovery tax on the central nervous system.