The ScienceBehind HRU
Built on decades of established physiological research and validated measurement technologies.
What We Measureand How
HRU is a multi-layer physiological systems analysis.
It does not diagnose disease; it detects functional efficiency, stress load, and recovery capacity across the body's key regulatory layers.
Technology
- Advanced Bioelectrical Impedance Analysis
What is Measured
- Total Body Water (TBW)
- Intracellular Water (ICW)
- Extracellular Water (ECW)
- ECW / ICW ratio
- Extracellular Matrix volume
- Phase Angle (PA°)
How It Works
- A low-intensity alternating electrical current passes through the body
- Resistance and reactance differ between fluids, cell membranes, and matrix
- From these values we derive cell membrane integrity, hydration quality, and matrix expansion
Why It Matters
- ↓ PA°, ↑ ECW, ↑ matrix = inflammatory and stress-driven inefficiency
- These shifts occur long before abnormalities appear in blood tests or imaging
Technology
- Photoplethysmography (PPG)
What is Measured
- Pulse wave variability
- Sympathetic vs parasympathetic dominance
- Stress reactivity patterns
- Recovery speed after micro-stress
How It Works
- Optical sensors analyse blood volume changes in the microcirculation
- Variability in the waveform reflects autonomic control and adaptability
Why It Matters
- Chronic stress shows up as loss of variability, not "high stress"
- Flattened patterns correlate with fatigue, poor sleep, reduced cognitive and physical recovery
Technology
- Extracellular Electrolytic Tomography
What is Measured
- Extracellular electrical conductivity
- Electrolyte distribution (Na⁺, K⁺, Cl⁻ driven conduction)
- Local extracellular fluid congestion
- Matrix densification and impedance
- Left–right or regional asymmetries
How It Works
- Low-intensity electrical signals are applied across defined tissue regions
- The system measures impedance, conductivity gradients, and signal dispersion
- These values are reconstructed into a tomographic map of extracellular behaviour
Why It Matters
- The extracellular matrix is where chronic stress accumulates first
- Electrical dysfunction appears before pain, stiffness, or structural damage
- Explains why people feel heavy, rigid, or fragile despite "normal scans"
What it is NOT
Technology
- Near-Infrared Spectroscopy (NIRS / HEG)
What is Measured
- Prefrontal cortex oxygen utilisation
- Cerebral blood flow efficiency
- Cognitive fatigue and load patterns
How It Works
- Infrared light penetrates superficial cortical tissue
- Reflected spectra differentiate oxygenated vs deoxygenated haemoglobin
Why It Matters
- Cognitive fatigue is often an oxygen utilisation problem, not motivation
- Early marker of performance decline in executives, athletes, and high-stress professionals
How the Four Layers Integrate
Global hydration, cellular efficiency, matrix volume
Nervous system control and recovery capacity
Where stress becomes local and physical (extracellular matrix)
Central nervous system performance and fatigue perception
Together, they answer one question:
Is the body converting stress into adaptation — or into inflammation, rigidity, and decline?
HRU measures systemic and local stress by combining cellular bioimpedance, autonomic regulation, extracellular electrolytic tomography, and brain oxygenation — detecting loss of efficiency long before disease appears.
The Challenge
Why HRU Exists: From Medically Unexplained Symptoms (MUS)to Measurable Data
In every healthcare system there is a growing group of people who feel unwell, yet standard tests come back "normal". Their symptoms are real — fatigue, non-specific pain, gut discomfort, palpitations, poor sleep — but don't fit neatly into a disease box.
HRU is designed to sit exactly in that gap
To objectively map the physiological terrain behind the "body whispers": the early, subclinical changes in stress axis, fluid distribution, matrix congestion and cellular efficiency that often precede overt disease.
What large MUS studies and expert guidance agree on:
- These patients are not "imagining it"
- Their symptoms often sit at the intersection of chronic stress, low-grade inflammation, altered body composition, and autonomic dysregulation
- These processes are measurable, but not captured by routine blood work or imaging
Global Research Data
MUS Prevalence: A Growing Global Concern
Global research reveals concerning trends in medically unexplained symptoms across a massive international sample of over 1.2 million participants.*
Year-over-Year MUS Prevalence
Percentage of subjects with MUS presence
Gender Distribution
Most Common Symptoms
Most prevalent medically unexplained symptoms
Consistent Prevalence
MUS affects approximately two-thirds of the population consistently across years, highlighting the need for better diagnostic approaches.
Systemic Patterns
Symptoms cluster across autonomic, digestive, and mood systems — suggesting interconnected physiological dysfunction that standard tests miss.
Evidence Base
Scientific Validation & Medical Literature Support
The following peer-reviewed studies and long-term research projects support the physiological principles measured by HRU. These studies span performance science, clinical physiology, and applied human optimisation.
Nervous System Regulation & Stress Physiology
Chrousos GP, et al. (2022). PPG-determined HRV and extracellular water in the evaluation of chronic stress and inflammation. Hormones.
→ Validates PPG-HRV for stress assessment
Wiley CR, et al. (2025). The interplay between heart rate variability, inflammation, and lipid accumulation. Physiol Rep.
→ Links HRV to inflammatory load
Shaffer F, Ginsberg JP (2017). An overview of heart rate variability metrics and norms. Front Public Health.
→ Establishes HRV measurement standards
Cellular Function, Hydration & Tissue Readiness
Tsigos C, et al. (2015). Stress and inflammatory biomarkers and symptoms are associated with bioimpedance measures. Eur J Clin Invest.
→ Connects bioimpedance to stress physiology
Boschiero D, Semenzato A (2009). Stress, vague symptoms and chronic inflammation: TomEEx extracellular bioimpedance tomography. TomEEx Research.
→ Foundation for extracellular analysis
Perez-Morales R, et al. (2021). Extracellular water/total body water ratio as predictor of mortality in hemodialysis patients. Ren Fail.
→ ECW/TBW clinical significance
Lai TF, et al. (2025). Elevated extracellular water to total body water ratio and mortality. Clinical Research.
→ ECW as health predictor
Park KS, et al. (2021). ECW/TBW and sarcopenia. Aging Clin Exp Res.
→ Links hydration to muscle health
Medically Unexplained Symptoms
Marks E (2015). Medically unexplained symptoms: an acceptable term?. Br J Gen Pract.
→ Defines MUS clinical context
Jadhakhan F, et al. (2019). Prevalence of medically unexplained symptoms in adults. BMJ Open.
→ Establishes MUS prevalence
Husain M, et al. (2021). Medically unexplained symptoms: assessment and management. Clin Med.
→ MUS assessment approaches
* MUS prevalence data from BioTekna's Epidemiological Observatory
See what your report reveals
Every HRU assessment generates a comprehensive report showing how your systems are functioning together. Clear visualisations, professional interpretation, and actionable guidance.
Multi-system efficiency overview
Key biomarkers with clear explanations
Traffic light indicators for quick reference
Personalised recommendations
Progress tracking over time
HRU Analysis Report
System Overview
Sample Report
System Efficiency Scores
Autonomic
78%
Metabolic
65%
Cellular
82%
Inflammatory
71%
Cardiovascular
85%
Recovery
58%
Key Metrics
HRV Index
42ms
Phase Angle
6.2°
ECW/TBW
0.39
Stress Load
Moderate
Personalised Recommendations
Your full report includes tailored guidance based on your unique results...
Our Foundation
Tested Over Time — Not Built Overnight
HRU is built on technologies and physiological principles that have been studied, refined, and applied for years across medical, sports, and performance environments. What is new is not the science — but the integration, structure, and accessibility of the data.
"HRU translates proven physiology into clarity, direction, and measurable change."
Take the Next Step
Ready to Understand Your Body's Signals?
Book your HRU analysis and discover what conventional medicine might be missing.
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