Interpreting Pro Plus Research Data
This article explores the scientific rationale and research-backed interpretation of the assessments provided in the emWave Pro Plus system. It focuses on how to determine autonomic regulation, stress response, and resilience/fatigue status.
1. Why the 1-Minute Deep Breathing Assessment?
Research indicates that the overall amount of HRV is the best indicator of ANS health, involving the lower brain, vagus nerves, and heart.
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Accuracy: This 1-minute test has strong correlations with the “gold standard” 24-hour HRV assessments for parasympathetic activity (HF, RMSSD) and even VLF activity.
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Vagal Dominance: During this guided deep-breathing test, HRV is generated almost entirely by the vagus (parasympathetic) system.
2. Key Research Markers & Interpretation
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Mean Heart Rate Range (MHRR):
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What it is: The average difference between the maximum and minimum heart rate during each 10-second breath cycle.
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Why it matters: It is the easiest metric to explain. Ideally, a client’s MHRR should fall near or above the center of the age-adjusted reference range.
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Warning Sign: Values at the bottom of the range or below it suggest reduced resilience or potential health risks.
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SDNN (Standard Deviation of Normal-to-Normal Intervals):
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In 1-Minute Tests: Acts as a marker for overall nervous system function.
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Comparison: Unlike in 24-hour recordings, the SDNN in a 1-minute deep breathing test is highly correlated with vagal activity.
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RMSSD (Root Mean Square of Successive Differences):
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Role: Reflects parasympathetic dominance and the body’s capacity to regenerate.
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Interpretation: Low RMSSD values suggest poor regenerative capacity and potential “parasympathetic burnout,” which is often more concerning than simple sympathetic dominance.
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Normalized Coherence:
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Medulla Coupling: If this score is below the normative range during a 1-minute test, it may indicate a lack of proper coupling between the respiratory and cardiovascular control centers in the medulla.
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3. Normative Data and Confidence Intervals
All client values are compared against a database of healthy individuals of the same age.
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95% Confidence Intervals: The “normal” range is defined as approximately two standard deviations above and below the mean.
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Athletes vs. General Population: Healthy athletes with high-resilience lifestyles define the top of the range, while healthy but less fit individuals define the bottom.
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Chronological vs. Biological Age: If a client’s value sits in the middle of the range, their biological age is well-matched to their chronological age.
4. Sympathetic vs. Parasympathetic Dominance
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First Stage of Stress: Often manifests as sympathetic dominance (high heart rate, low coherence).
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Advanced Stress: Parasympathetic burnout is the later, more significant stage of stress.
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VLF (Very Low Frequency): Low VLF is a critical marker associated with future health risks. The 1-minute deep breathing assessment is uniquely capable of providing a reliable VLF correlation compared to other short-term resting tests.