HRVDex — Heart Rate Variability Analyzer

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Drop your HRV exports here

Welltory CSV or an ECGDex export (CSV / JSON) · imports are additive — drop many files or nights at once and they stack into one multi-day table (exact duplicates are skipped). Your history is saved in this browser between visits; use Clear saved history to wipe it. All processing is local — no data leaves your device
📱 Android: if a file is grayed out, tap the ⋮ menu → "Show all files"

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🔬 Power-user companion analytics

This tool computes biometric patterns from your wearable data to support personal self-quantification. It is not a medical device, does not diagnose, treat, or screen for any condition, and is not a substitute for clinical evaluation. Derived metrics (VO₂max, HRV proxies, AHI estimates, blood pressure projections) are experimental approximations — not validated diagnostic outputs. Consult a qualified clinician for any health concern.

📊 Key Metrics🌅 Morning measurements only

Import a Welltory CSV or an ECGDex export to analyze 85+ HRV metrics from your ANS data.

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Import your HRV data to begin

Reads the Welltory CSV format (SDNN, rMSSD, HF/LF/VLF, Stress, Energy, and all ANS fields) and ECGDex exports (CSV / JSON). Imports are additive — add more nights anytime and they accumulate.

View Window:

Measurements:

Smoothing: 0

📈 Overview

⏱ Time-Domain HRV

🌊 Frequency-Domain

🧮 Composite & ANS

🔄 Rolling / Trend

🏥 Clinical Risk

🔵 Poincaré & Toichi

🧠 Cognitive & Resilience

📊 Distributions & Patterns

🏃 VO₂max & BP

📋 Raw + Derived Table

rMSSD (Parasympathetic Tone)

ln(rMSSD) — gold standard for daily readiness

HRV Score & SDNN

Primary readiness indicators

SNS vs PSNS Balance

Sympatho-vagal autonomic load

Advanced

LF/HF Ratio

Sympathovagal balance. Optimal 0.5–2.0 (morning rest)

Advanced

Baevsky Stress Index

AMo50² / (2 × Mode × MxDMn) — classic autonomic load. Normal <150

Advanced

Vagal Efficiency (rMSSD/HR)

HR-corrected parasympathetic output. Optimal >0.45

Research

DFA α1 Proxy

⚠ No validated formula — derived from SD1/SD2. Directional trend only, not absolute DFA α1.

Research

DFA α1 Proxy (overview)

⚠ No validated formula — derived from SD1/SD2. Directional trend only, not absolute DFA α1.

Stress vs Energy (HRV)

Divergence gap = autonomic dysregulation signal

Baevsky Stress Index (SI)

AMo50² / (2 × Mode × MxDMn) — classic autonomic load. Normal <150, stress >200

CV (Coefficient of Variation)

SDNN / MeanRR × 100 — HR-normalized HRV

RMSSD/SDNN Ratio

Parasympathetic fraction of total HRV. Optimal 0.5–0.9

MxDMn / MeanRR Ratio

Normalized heart period variability range

Stress–Energy Divergence

|Stress − Energy| gap. Large gap = dysregulation flag

ln(rMSSD) — HRV4Training Readiness

Log-transformed parasympathetic readiness score

LF/HF Ratio

SNS/PSNS balance. Optimal 0.5–2.0 (morning rest)

HF & LF Normalized Units (nu)

HFnu = HF/(Total−VLF)×100 | LFnu = LF/(Total−VLF)×100

VLF % of Total Power

>50% = slow regulatory load or poor signal quality

Sympathovagal Index = ln(LF) − ln(HF)

Log-scale ANS balance. Negative = vagal dominant

Spectral Entropy (LF/HF/VLF distribution)

High (→1) = power evenly spread across all bands (balanced ANS). Low (→0) = one band dominates (e.g. VLF-dominant = slow regulatory load). Neither extreme is unconditionally good.

LF+HF / Total Power

Fraction of power in autonomically meaningful bands

ANS Load Score

(SNS × Stress) / (PSNS × Energy + 1) — composite burden

Coherence × Energy Product

Weighted readiness score — both must be high simultaneously

Parasympathetic Tone Index

PSNS × rMSSD / 100 — combined PSNS estimate

Stress × (1/Coherence) — Incoherent Stress

High = stressed AND dysregulated simultaneously

Vagal Efficiency Index = rMSSD / HR

HR-corrected parasympathetic output. Optimal >0.5

Sympathetic Dominance Index

(LF + SNS×10) / (HF + PSNS×10)

Autonomic Recovery Index (rMSSD ratio)

Today ÷ 7-day mean. >1.05 = better than baseline

7-day SDNN Z-Score

Deviation from personal rolling baseline (±1SD flags)

7-day rMSSD Rolling Mean (ln)

HRV4Training gold-standard readiness baseline

Rolling Stress Area Under Curve (7d)

Cumulative autonomic stress load

7-day rMSSD CV (Instability)

Day-to-day HRV variability — high = unstable recovery

Stress Autocorrelation (lag-1)

High persistence = chronic stress; low = acute event

HRV Momentum (14d ln(rMSSD) Slope)

Positive = improving HRV trend; negative = declining. Key long-term training signal.

Restoration Index (Energy × Coherence / Stress+1)

High = physiologically resourced day. Both numerators must be elevated simultaneously.

Recovery Debt (ARI <0.9 days in 14d window)

Accumulating days below baseline recovery signal chronic fatigue burden.

rMSSD Day-to-Day Reactivity (%)

Daily % change in rMSSD vs previous consecutive measurement. Gap >1 calendar day = shown as blank (not meaningful across missed days).

Baevsky Adaptation Potential

0.011×HR + 0.014×age (HR+Age component only) — full formula needs SBP/DBP. Trend direction valid; absolute threshold not applicable without BP input.

Orthostatic Load Proxy

HR × (1/SDNN) — combined cardiac load index

pNN50 Decline Rate (Rolling Slope)

Negative slope = overtraining / autonomic suppression signal

High-Stress / Low-Energy Days

Binary flag: Stress >60 AND Energy <40 — monthly load count

Cardiovascular Research Pattern

ℹ️

Research-grade indicators

These scores are derived from HRV pattern analysis. They are NOT blood pressure measurements and do NOT replace cuff-based monitoring. Individual variation, medications (especially beta-blockers), and confounders (sleep quality, recent exercise, illness) significantly affect them. References at bottom.

Cardiac Autonomic Modulation Quality (CAMQ)

Composite autonomic balance: parasympathetic dominance minus sympathetic dominance. Higher = healthier autonomic state.

>60 healthy 30–60 borderline <30 sympathetic-dominant

Weighted score: parasympathetic indicators (RMSSD, HF power, pNN50) minus sympathetic indicators (LF/HF, AMo50). Lower scores correlate with elevated BP risk in population studies.

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References

• Yu et al. 2018, Int J Hypertens — HRV & heart-rate turbulence in hypertensive patients
• ARIC Study (Schroeder et al. 2003), Hypertension — decreased HRV in hypertension (SDNN, RMSSD)
• Toon Health Study (Saito et al. 2018), Am J Hypertens 31(10):1120–6 — home BP × HRV quartiles
• HELIUS Study (2024) — xBRS predicts incident hypertension over 6.6yr

SD1 vs SD2 (Poincaré Geometry)

SD1 = instantaneous beat variability (pure vagal) · SD2 = long-term regulation

SD1/SD2 Ratio

0.25–0.35 = typical resting; <0.25 = LF/sympathetic dominance; >0.5 = vagal dominant

Toichi CVI (Cardiac Vagal Index)

log₁₀(rMSSD_ms × MeanRR_ms) — orthogonal to CSI; higher = more vagal tone. Thresholds: >4.4 good · 4.1–4.4 moderate · <4.1 suppressed

Toichi CSI (Cardiac Sympathetic Index)

MxDMn / MeanRR_s — independent sympathetic index; higher = more sympathetic drive

CVI vs CSI (Autonomic Quadrant)

Scatter: upper-left = vagal dominant; lower-right = sympathetic dominant

DFA α1 Proxy & HRV Power Law Slope

⚠ DFA proxy is derived from SD1/SD2 — no published formula exists; use as a directional trend only, not absolute DFA α1. Power law slope: less negative = HF-dominant

VLF/HF Ratio & Spectral Asymmetry

VLF/HF >3 = slow regulatory dominance · SAI: −1=vagal, +1=sympathetic

Cardiac Autonomic Index (CAI) — √(SD1×SD2)

Geometric mean of Poincaré axes √(SD1×SD2). Higher = better autonomic control. Thresholds: >45 good · 30–45 moderate · <30 suppressed

EFC Readiness Index

Energy×0.4 + Focus×0.3 + Coherence×0.3 — combined cognitive + physiological readiness

Cardiac Resilience Score

(Coherence × rMSSD × pNN50) / (Stress×1000) — HRV quality buffered against stress load

Autonomic Balance Score (ABS)

(PSNS−SNS)/(PSNS+SNS) · −1=full SNS · 0=balanced · +1=full PSNS

Stress-Focus Dissociation

Stress − Focus. Positive = stress outpacing cognitive focus ("masked stress")

Focus Efficiency

Focus / (SNS+1) — cognitive output per unit sympathetic cost

PNS Efficiency Index

rMSSD / (SDNN × pNN50) — parasympathetic contribution vs total HRV. Shown as blank (—) when pNN50 <1% to avoid paradoxical inflation on high-stress days.

Overtraining Risk Index

(SNS/PSNS) × (100/pNN50) — composite overreaching flag; not standalone diagnostic

rMSSD Circadian-Adjusted vs Raw

Removes morning (+8%) and evening (−5%) bias for fair cross-measurement comparison

RSA Power Proxy & NN50 Estimate

RSA = HF/(MeanRR²) · NN50 = estimated count from pNN50 × beat count

🏃 VO₂max Daily Estimates

Method: Uth-Sørensen (2004) — 15.3 × (HRmax/HRrest), HRmax = Tanaka formula (208 − 0.7×age), altitude-corrected above 1500 m. HRV-adjusted = base × rMSSD ln-modifier (±8% band). Enter your VO₂max ground truth in the User Profile to anchor the delta chart. Accuracy: ±4–5 ml/kg/min SEE — use for trend direction, not exact value. Categories follow ACSM age- and sex-adjusted norms.

VO₂max Daily Estimate vs 7-Day Rolling Mean

Base (Uth-Sørensen HR ratio) vs HRV-adjusted vs rolling 7d mean. Enter a real VO₂max test result in the profile to anchor the ground truth reference line.

VO₂max Delta from Ground Truth

Daily deviation from profile VO₂max. ⚠ If GT was auto-inferred (not from a real test), this chart shows daily HR+rMSSD variation vs your median — not deviation from a true VO₂max measurement.

Resting HR vs VO₂max Estimate

Scatter: lower resting HR → higher VO₂max. Color = stress level.

rMSSD HRV Modifier (% adjustment to base VO₂max)

How much rMSSD adds or subtracts from the HR-only estimate each day.

📊 Distributions & Patterns

New analytical views over your full history — value distributions, day-of-week rhythms and cross-metric correlations. These read raw daily values across the selected date range and are independent of the time-series smoothing slider.

Metric Distribution

Histogram of any metric across the selected range. —

Metric

Correlation Explorer

Pick any two metrics to see how they move together. —

X Y

Day-of-Week Pattern

Average by weekday — surfaces weekly rhythms (weekend recovery, mid-week strain). —

Metric

🔗 Correlation Matrix

Pearson r across core metrics over the selected range. Teal = move together · red = inverse relationship · deeper colour = stronger. Hover any cell for the exact value.

📋 Full Derived Metrics Table

T Tepna physiological-signal suite

licenceApache-2.0

Drop your HRV exports here

👤 User Profile — personalizes all formulas & norms

Import your HRV data to begin

rMSSD (Parasympathetic Tone)

HRV Score & SDNN

SNS vs PSNS Balance

LF/HF Ratio

Baevsky Stress Index

Vagal Efficiency (rMSSD/HR)

DFA α1 Proxy

DFA α1 Proxy (overview)

Stress vs Energy (HRV)

Baevsky Stress Index (SI)

CV (Coefficient of Variation)

RMSSD/SDNN Ratio

MxDMn / MeanRR Ratio

Stress–Energy Divergence

ln(rMSSD) — HRV4Training Readiness

LF/HF Ratio

HF & LF Normalized Units (nu)

VLF % of Total Power

Sympathovagal Index = ln(LF) − ln(HF)

Spectral Entropy (LF/HF/VLF distribution)

LF+HF / Total Power

ANS Load Score

Coherence × Energy Product

Parasympathetic Tone Index

Stress × (1/Coherence) — Incoherent Stress

Vagal Efficiency Index = rMSSD / HR

Sympathetic Dominance Index

Autonomic Recovery Index (rMSSD ratio)

7-day SDNN Z-Score

7-day rMSSD Rolling Mean (ln)

Rolling Stress Area Under Curve (7d)

7-day rMSSD CV (Instability)

Stress Autocorrelation (lag-1)

HRV Momentum (14d ln(rMSSD) Slope)

Restoration Index (Energy × Coherence / Stress+1)

Recovery Debt (ARI <0.9 days in 14d window)

rMSSD Day-to-Day Reactivity (%)

Baevsky Adaptation Potential

Orthostatic Load Proxy

pNN50 Decline Rate (Rolling Slope)

High-Stress / Low-Energy Days

Cardiovascular Research Pattern

Cardiac Autonomic Modulation Quality (CAMQ)

SD1 vs SD2 (Poincaré Geometry)

SD1/SD2 Ratio

Toichi CVI (Cardiac Vagal Index)

Toichi CSI (Cardiac Sympathetic Index)

CVI vs CSI (Autonomic Quadrant)

DFA α1 Proxy & HRV Power Law Slope

VLF/HF Ratio & Spectral Asymmetry

Cardiac Autonomic Index (CAI) — √(SD1×SD2)

EFC Readiness Index

Cardiac Resilience Score

Autonomic Balance Score (ABS)

Stress-Focus Dissociation

Focus Efficiency

PNS Efficiency Index

Overtraining Risk Index

rMSSD Circadian-Adjusted vs Raw

RSA Power Proxy & NN50 Estimate

VO₂max Daily Estimate vs 7-Day Rolling Mean

VO₂max Delta from Ground Truth

Resting HR vs VO₂max Estimate

rMSSD HRV Modifier (% adjustment to base VO₂max)

Metric Distribution

Correlation Explorer

Day-of-Week Pattern