Polar H10 Monitor

	Date	Name	Duration	Samples	Avg RR	RMSSD	SRI	Events	Tags	Actions

Connection

Not Connected

Data Quality: --

Recording

⏱ 00:00

Export Data

RR only

Include raw data

Heart Rate

--BPM

RMSSD (1 min)

--ms

RR Intervals

Avg RR (1 min)

--ms

Stress Recovery Index

Real-time autonomic nervous system balance

What is SRI?

The Stress Recovery Index (SRI) is a composite score (0-100) that quantifies your autonomic nervous system balance and recovery capacity. Higher scores indicate better stress resilience and parasympathetic activity.

How is it Calculated?

SRI combines three validated Heart Rate Variability (HRV) metrics with scientifically-weighted contributions:

35%

RMSSD (Root Mean Square of Successive Differences)

Measures beat-to-beat variability. Higher values indicate greater parasympathetic (rest-and-digest) activity. Optimal: >50ms

35%

LF/HF Ratio (Low Frequency / High Frequency)

Balance between sympathetic and parasympathetic activity via frequency domain analysis. Lower ratios indicate better recovery. Optimal: 0.5-2.0

30%

HR Recovery Rate

Speed of heart rate decrease from peak to baseline. Faster recovery indicates better cardiovascular fitness and autonomic regulation.

Interpretation

75-100 Excellent Recovery

Optimal autonomic balance, strong parasympathetic activity

55-74 Good Recovery

Healthy stress response, adequate recovery capacity

35-54 Fair Recovery

Moderate stress detected, may benefit from relaxation techniques

0-34 Poor Recovery

High stress levels, prioritize recovery and rest

Scientific Validation

This index is based on well-established HRV research:

RMSSD: Task Force of the European Society of Cardiology (1996) - Gold standard for parasympathetic activity measurement
Frequency Domain Analysis: Validated by hundreds of peer-reviewed studies for autonomic assessment
HR Recovery: Proven predictor of cardiovascular health and mortality risk (Cole et al., NEJM 1999)

Best Practices

Measure SRI at consistent times (e.g., morning, before exercise)
Allow at least 2 minutes of stable recording for accurate results
Track trends over days/weeks rather than single measurements
Use alongside subjective stress assessment for complete picture
Ensure proper sensor contact for data quality >95%

SRI Score

RMSSD

LF/HF Ratio

HR Recovery

⏱️

Calculating... Need at least 2 minutes of data

ECG Signal

RR Intervals

Rolling RMSSD (1 min)

Poincaré Plot

Power Spectral Density

❤️ Polar H10 Monitor

Session History

Mark Event

📋 Session Table

About the Stress Recovery Index

What is SRI?

How is it Calculated?

Interpretation

Scientific Validation

Best Practices