How HRV Deload Trigger works

Scope

Decides whether your last 7 days of HRV (RMSSD ms or readiness 0–100) signal a deload, comparing the rolling 7-day mean against a user-provided 30-day baseline using the Plews et al. (2014) method.

Formula

SWC (smallest worthwhile change) = 0.5 × baseline_std_dev. If baseline std dev isn't supplied, the tool defaults to 7% of baseline (Plews 2014 typical CV).

Daily flag: belowSwc = (value − baseline) < −SWC.

Recommendation:

• yes: rolling 7-day mean < baseline − 1.5×SWC AND ≥2 consecutive days below SWC.
• yes: rolling 7-day mean < baseline − SWC AND ≥3 consecutive days below SWC.
• maybe: rolling mean < baseline − SWC OR ≥2 consecutive days below SWC.
• no: otherwise.

Data sources

1. Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports Med. 2013;43(9):773-781. — PMID 23580315. The rolling-baseline approach to HRV monitoring.
2. Plews DJ, Laursen PB, Le Meur Y, Hausswirth C, Kilding AE, Buchheit M. Monitoring training with heart-rate variability: how much compliance is needed for valid assessment? Int J Sports Physiol Perform. 2014;9(5):783-790. — PMID 24338609. The 7-day rolling mean and SWC framework.

Assumptions

• Daily HRV is measured first thing in the morning, supine or seated, before caffeine — Plews 2014 protocol.
• Baseline reflects a steady training state; recent macro shifts (illness recovery, big training jump) invalidate the baseline.
• RMSSD or 0–100 readiness scores both work — only the relative deviation matters.

Approximation range

HRV is noisy by nature. The 7-day rolling mean smooths roughly 70% of day-to-day noise (Plews 2014). A "yes" trigger has an estimated 60–75% true-positive rate for actual training fatigue.

Limitations

• Doesn't model context (illness, alcohol, poor sleep, travel) which all suppress HRV without indicating overreach.
• Baseline std dev is a guess unless you measure it — using a default of 7% is reasonable but personalising it is better.
• Decisions should integrate subjective wellness (RPE, motivation, sleep) — not be HRV-only.

Reproducibility

Baseline 56, std dev 4 (default 7% × 56 ≈ 3.92). SWC = 0.5 × 4 = 2. Daily series 55, 54, 52, 50, 48, 47, 46. 7-day mean = 50.3. Δ = −5.7, < −SWC AND < −1.5×SWC (−3). Longest consecutive below-SWC run = 5 days. → Recommendation: yes.

Change log

• 2026-05-08: methodology page first published.

Related tools

• Resting Heart Rate Calculator — Companion physiological metric.
• Sleep Debt Calculator — Sleep-side recovery monitoring.

Worked example

Computed by the same engine bundle served at /engines/hrv-deload-trigger.js. Re-runnable: the values below are the literal output of compute(engineInput).

FAQ

What does the HRV Deload Trigger calculate?

Methodology for the HRV Deload Trigger: Plews 2014 rolling-baseline method, smallest worthwhile change, and consecutive-day decision rules.

What inputs does the HRV Deload Trigger require?

It takes the following inputs: daily, baseline 30 day, baseline std dev.

What does the HRV Deload Trigger return?

It returns: recommendation, rollingMean7Day, rollingDeviationPct, smallestWorthwhileChange, daysBelowSwcInLastWeek, longestConsecutiveBelowSwc, detail.

Is the HRV Deload Trigger free to use?

Yes. It runs entirely client-side in your browser with no signup, and is also importable as an ES module engine for AI agents.

What category does the HRV Deload Trigger belong to?

Recovery. See the methodology above for formulas, assumptions, and limitations.