How ready are you?

Four inputs flow into the score, in order of influence:

• TSB (form) — the single biggest daily signal. Fresh TSB bumps the score, deeply negative TSB tanks it.
• Monotony — 7-day Foster monotony. Above 1.3 starts subtracting points, above 2.0 penalizes heavily.
• Days since last quality — days since your last Z4+ session. 0 days subtracts 5 points (just hit it); 4+ days adds 3 points (recovered).
• Rule-engine hard caps — if a safety rule is active, the score is capped regardless of other inputs.

Start at 70. Adjust from there:

TSB component (±25 points)

• TSB > +25: −10 (stale/overtapered)
• TSB +5 to +25: +15 (fresh)
• TSB −5 to +5: +5 (fit)
• TSB −15 to −5: −5 (overreached short-term)
• TSB −30 to −15: −15
• TSB < −30: −25

Monotony penalty

• Monotony > 2.0: −15
• Monotony > 1.5: −8
• Monotony > 1.3: −3

Recovery since last quality

• Today: −5
• Yesterday: −2
• 2–3 days: 0
• 4+ days: +3

Hard caps (safety)

• NEGATIVE_TSB_PROLONGED → capped at 40
• ACUTE_SPIKE → capped at 50
• HIGH_MONOTONY → capped at 55
• CROSS_SPORT_LOAD_ADD → capped at 55

Caps take precedence. If you’re in ACUTE_SPIKE, even perfect sleep and a week off last week won’t push your readiness past 50 — because the safety flag is still on.

80–100 — Primed

Green light for intensity if the plan calls for it.

65–79 — Ready

Normal training. Build or quality session as prescribed.

50–64 — Fit but tired

Prefer quality over volume. Short sharp sessions beat long volume today.

35–49 — Underrecovered

Easy aerobic only or take the day off if the legs feel heavy.

Under 35 — Recovery day

Rest, mobility, or very easy spin. Do not force it.

Most device-based readiness scores (Garmin, Whoop, Oura) use sleep duration, HRV, and resting HR. We don’t — for two reasons:

• Strava doesn’t publish that datavia its API, so we’d need a separate device integration per vendor. Outside MVP scope.
• Training load alone is remarkably predictive. TSB + monotony + recovery-since-quality explains most of the variance. Sleep/HRV adds precision, not a new signal.

If we add Garmin Connect integration later, the score will fold sleep and HRV in as modifiers — not replacements.