Regulation Score
Daily nervous system summary (0–100)
- Combines HRV, RHR, sleep, and respiratory rate into one score
- 70–100: Balanced & restorative
- 50–69: Steady but watchful
- 0–49: Elevated stress — prioritize recovery
The science
Signals 101 — Understanding what your body is telling you
Your nervous system constantly adapts to stress and recovery. These five signals — and the practices that move them — are the foundation of SoMana. Every claim below is anchored in peer-reviewed research.
Key metrics
Your body's primary communication channels
Five signals SoMana tracks from Apple Health — and what each one actually tells you.
Heart Rate Variability (HRV)
Autonomic nervous system adaptability
- Higher variability = better resilience and balance
- Reflects parasympathetic (rest & digest) activity
- Measured in milliseconds (SDNN)
- Drops with stress, illness, overtraining, and poor sleep
Resting Heart Rate (RHR)
Baseline cardiovascular load
- Lower generally indicates better fitness & recovery
- Elevations suggest stress, illness, or incomplete recovery
- Best measured upon waking
- Responds to training load, sleep, and hydration
Sleep Quality
Foundation for nervous system recovery
- Deep sleep drives physical recovery
- REM supports emotional processing
- Sleep efficiency = time asleep vs. time in bed
- Consistency stabilizes circadian rhythm
Respiratory Rate
Breaths per minute, autonomic signal
- Adult resting range: 12–20 breaths/min
- Lower rates indicate better autonomic balance
- Elevations may signal stress or anxiety
- Directly trainable through breathwork
Research foundation
The peer-reviewed evidence behind SoMana's practices
Every practice inside SoMana is grounded in published research. Below are the studies that inform what we build. Filter by intervention to find the ones that matter to you.
Slow Breathing
Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and meta-analysis
Voluntary slow breathing leads to an increase in parasympathetic nervous control of the heart, with increased RMSSD during practice, immediately after, and after multi-week interventions.
Resonance Breathing
Effect of resonance breathing on heart rate variability and cognitive functions in young adults: A randomised controlled study
4 weeks of daily resonance breathing significantly improved HRV parameters (SDNN, pNN50, total power), cognitive performance, and reduced perceived stress.
Resonance Frequency Breathing
The impact of resonance frequency breathing on measures of heart rate variability, blood pressure, and mood
Breathing at resonance frequency resulted in higher LF/HF ratio, more positive mood, and decreased blood pressure response to stress compared to controls.
Mantram Repetition
A spiritually based group intervention for combat veterans with posttraumatic stress disorder: Feasibility study
Small RCT of combat veterans found mantram repetition produced large effect sizes on PTSD severity (d = -0.72), psychological distress (d = -0.73), and quality of life (d = 0.70).
Cold Exposure
The effects of cold exposure on cardiovascular and cardiac autonomic control responses in healthy individuals: A systematic review, meta-analysis and meta-regression
Significant increases in RMSSD, RR interval, and HF power, with reduced LF and LF/HF ratio persisting up to 15 minutes after cold exposure.
Cold Face Test
Vagus activation by Cold Face Test reduces acute psychosocial stress responses
Cold facial stimulus induced parasympathetic activation, improved stress recovery, and significantly reduced cortisol increase after acute stress.
Gratitude Journaling
Pilot randomized study of a gratitude journaling intervention on heart rate variability and inflammatory biomarkers in patients with Stage B heart failure
8 weeks of gratitude journaling increased parasympathetic HRV and reduced inflammatory biomarkers compared to treatment as usual.
Physical Activity
Beneficial impacts of physical activity on heart rate variability: A systematic review and meta-analysis
Physical activity significantly improved RR interval, SDNN, RMSSD, and HF power, especially in patients with chronic heart failure.
Journaling
Efficacy of journaling in the management of mental illness: A systematic review and meta-analysis
Meta-analysis of 20 RCTs showed journaling interventions resulted in 5% greater reduction in mental health symptom scores compared to controls.
Exercise
Effects of different exercise interventions on heart rate variability and cardiovascular health factors in older adults: A systematic review
Endurance, multimodal, and coordinative training improve cardiac autonomic control and cardiovascular health factors in older adults.
Cyclic Sighing
Brief structured respiration practices enhance mood and reduce physiological arousal
5 minutes per day of cyclic sighing over 28 days improved mood and lowered resting respiratory rate more than mindfulness meditation, box breathing, or cyclic hyperventilation.
Slow Breathing (Review)
How breath-control can change your life: A systematic review on psycho-physiological correlates of slow breathing
Comprehensive review showing slow breathing (< 10 breaths/min) increases parasympathetic activity, improves emotional control, and shifts CNS activity toward relaxation and well-being.
Trait Gratitude
The role of gratitude in spiritual well-being in asymptomatic heart failure patients
Higher gratitude scores correlated with better sleep, less depressed mood, less fatigue, better cardiac self-efficacy, and lower inflammatory biomarkers in Stage B heart failure patients.
Gratitude
Effects of gratitude intervention on mental health and well-being among workers: A systematic review
Systematic review of gratitude RCTs in working populations found perceived stress and depression improved significantly across the trials measuring those outcomes, with positive affect gains across additional trials.
Expressive Writing
Research on expressive writing in psychology: A forty-year bibliometric analysis and visualization of current status and research trends
Forty-year bibliometric review of the Pennebaker paradigm documents expressive writing's effects on immune function, fewer health-center visits, reduced anxiety, and mediated depression symptoms across decades of studies.
Expressive Writing (Meta-Analysis)
Written emotional expression: Effect sizes, outcome types, and moderating variables
Meta-analysis found written emotional expression produced an effect size of d = 0.47, equating to roughly a 23% improvement over controls across reported physical health, psychological well-being, physiological functioning, and general functioning.
Positive Writing (Meta-Analysis)
Efficacy of expressive writing versus positive writing in different populations: Systematic review and meta-analysis
Meta-analysis of 24 RCTs comparing positive writing to trauma-focused expressive writing found positive writing produced greater mood and cognitive gains in general populations, while expressive writing helped clinical patients more.
Mantra Recitation
Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: Comparative study
Both rosary prayer and yoga mantras independently slowed breathing to ~6 breaths/minute, synchronizing cardiovascular rhythms and significantly increasing baroreflex sensitivity.
Mantram Repetition Program
Targeting hyperarousal: Mantram Repetition Program for PTSD in US veterans
Two-site RCT of 173 veterans found the Mantram Repetition Program produced significantly greater hyperarousal reductions than Present-Centered Therapy (d = 0.57 post-treatment, 0.52 at follow-up), and hyperarousal reduction mediated other PTSD gains.
Interoception (Body Awareness)
Interoception and mental health: A roadmap
Consensus white paper framing interoception as a transdiagnostic mechanism across anxiety, mood, eating, addictive, and somatic-symptom disorders. Sharper interoceptive awareness is linked to better emotional regulation.
Body Awareness Measurement
The Multidimensional Assessment of Interoceptive Awareness (MAIA)
Development and validation of the MAIA, a 32-item self-report questionnaire across 8 dimensions of interoceptive body awareness; now the standard measurement instrument used to study body-based interventions.
Somatic Experiencing
Somatic Experiencing for posttraumatic stress disorder: A randomized controlled outcome study
First RCT of Somatic Experiencing (n=63 with full DSM PTSD): large effects on PTSD symptom severity (Cohen's d = 0.94–1.26) and depression (d = 0.7–1.08); 44.1% no longer met PTSD criteria post-treatment, with gains held at follow-up.
Contemplative Body Awareness
Interoception, contemplative practice, and health: Relations to brain mechanisms, mental health, and psychological well-being
Comprehensive review proposing that sustained contemplative practice may reshape how the brain integrates interoceptive signals over time, linked to long-term improvements in mental health and psychological well-being.
No studies match that filter.
These studies demonstrate measurable physiological improvements from the practices integrated in SoMana. Research consistently shows that simple, consistent interventions can significantly enhance autonomic nervous system function.
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