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Mathematical Modeling

Performance Management Chart (PMC)

How the rolling daily training load calculates your current cardiovascular fitness, fatigue, and racing readiness.

Core PMC Components

CTL (Chronic Training Load)
"Fitness". An exponentially-weighted rolling 42-day average of daily training stress. It represents your long-term training volume and your body's structural ability to withstand high training loads.
ATL (Acute Training Load)
"Fatigue". An exponentially-weighted rolling 7-day average of daily training stress. It represents your short-term fatigue from workouts performed over the past week.
TSB (Training Stress Balance)
"Form". Calculated simply as:
TSB = CTL - ATL It shows how "fresh" or recovered you are. A positive TSB indicates freshness, while a negative TSB suggests accumulated fatigue.

The Mathematics

The PMC uses **exponential decay** modeling rather than a simple rolling average. This represents the physiological reality that a workout performed yesterday causes more fatigue and adaptation than a workout performed 3 weeks ago.

// CTL (Fitness) Formula
CTLtoday = CTLyesterday × e-1/42 + DailyStress × (1 - e-1/42)
(Where e-1/42 ≈ 0.9765. DailyStress is TSS, or hrSS/sRPE fallbacks.)

// ATL (Fatigue) Formula
ATLtoday = ATLyesterday × e-1/7 + DailyStress × (1 - e-1/7)
(Where e-1/7 ≈ 0.8669.)

// TSB (Form) Formula
TSB = CTLyesterday - ATLyesterday

Training Stress & Form Guide

By tracking TSB, you can plan training sessions, avoid injury, and time peak race fitness.

TSB Range State Physiological Application
> +25 Transition / Rest Loss of fitness. Good for off-season, recovery weeks, or post-race transition.
+15 to +25 Peak / Race Ready Optimal fresh state for racing. Best time for an "A-race".
-10 to +10 Maintenance Healthy balance. Useful for active training blocks that don't overly tax the system.
-30 to -10 Optimal Building Your body is accumulating overload. Perfect zone to stimulate new physical adaptations.
< -30 Danger / Overtraining High fatigue state. Extremely high risk of injury, disease, or cardiovascular depression.
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