PMC Fitness/Fatigue Simulator
Use CTL, ATL, TSB and future weekly TSS to estimate six-week fitness, fatigue and race readiness.
This reverse-estimated range aims to keep future TSB around the -10 to -30 training-stimulus zone. If the week includes multiple VO2 or anaerobic sessions, practical planning should stay near the lower bound.
| Day | TSS | CTL | ATL | TSB |
|---|---|---|---|---|
| 8/8 | 0 | 43.9 | 45.1 | -7.0 |
| 8/14 | 129 | 48.3 | 65.0 | -8.8 |
| 8/21 | 129 | 51.2 | 69.8 | -11.5 |
| 8/28 | 129 | 53.6 | 71.6 | -11.1 |
| 9/4 | 129 | 55.6 | 72.3 | -9.7 |
| 9/11 | 129 | 57.3 | 72.5 | -8.3 |
| 9/18 | 129 | 58.7 | 72.6 | -6.9 |
CTL is a 42-day exponentially weighted trend of long-term training load, ATL is a 7-day trend of recent fatigue, and TSB is the difference between fitness and fatigue. This model traces back to the "impulse-response" framework proposed by Banister and colleagues: training produces two simultaneous effects — a long-lasting fitness gain (CTL) and a short-lived fatigue buildup (ATL) — and TSB quantifies "how you feel today" as the difference between the two. TSB below -30 does not automatically mean injury, but it does mean recovery should become a higher priority. Before racing, TSB is usually allowed to rise gradually.
Model source: Banister, Calvert, Savage & Bach 1975, Australian Journal of Sports Medicine