What could be causing my elevated Garmin stress score?

Understanding Your Elevated Garmin Stress Score

Your elevated Garmin stress score is most likely reflecting physiological responses to either physical demands (exercise intensity, inadequate recovery, illness) or psychological stressors (work pressure, sleep deprivation, emotional distress), measured through heart rate variability changes detected by your device's sensors.

How Garmin Measures Stress

Garmin devices calculate stress scores using heart rate variability (HRV)—specifically analyzing the variation in time intervals between heartbeats. When your body is under stress (physical or psychological), your sympathetic nervous system activates, reducing HRV and triggering higher stress scores 1. The standard deviation of interbeat intervals is one of the most important features for detecting stress states 1.

Primary Causes to Investigate

Physical Stressors

Overtraining or inadequate recovery is a leading cause in active individuals:

• Running more than 105 km weekly or less than 25 km weekly increases physiological stress 2
• Running frequency extremes (less than 2 times or more than 7 times weekly) affect stress markers 2
• Insufficient sleep between training sessions prevents HRV normalization

Acute illness or inflammation directly elevates stress scores:

• Inflammatory biomarkers (C-reactive protein, IL-6) link perceived stress with metabolic dysregulation 3
• Even subclinical infections cause measurable HRV changes
• Hemoconcentration from dehydration increases blood viscosity and stress markers 4

Psychological Stressors

Work-related strain shows robust associations with physiological stress markers 5:

• High-demand, low-control work environments (job strain)
• Long working hours or shift work
• Effort-reward imbalance situations

Acute psychological stress produces measurable physiological changes 6, 4:

• Increases in blood pressure and heart rate
• Hemoconcentration with elevated hematocrit
• Changes in blood viscosity and inflammatory markers
• These effects appear within minutes and are detected by wearable sensors

Critical Distinctions

Physical versus psychological stress show different patterns 7:

• Physical stress effects appear early (within 2 weeks) but are relatively moderate
• Psychological stress effects appear later (by week 4) but become more severe over time
• Psychological stress causes more pronounced hippocampal changes and may be harder to reverse

Between-person versus within-person variability matters 8:

• Approximately 50% of stress score variation reflects stable individual characteristics (how you typically perceive stress)
• The remaining 50% represents actual day-to-day fluctuations
• Shorter assessment periods show higher between-person variance

Actionable Steps to Identify Your Cause

1. Review your training load: Check if you've increased running distance by more than 10% weekly or are running at extremes (very low or very high frequency) 2

2. Assess sleep quality: Poor sleep is the most common reversible cause of elevated stress scores in otherwise healthy individuals

3. Check for illness symptoms: Low-grade fever, fatigue, muscle aches, or recent infection

4. Evaluate work demands: Identify if you're experiencing job strain (high demands with low control over your work) 5

5. Monitor hydration status: Dehydration causes hemoconcentration and elevated stress markers 4

6. Consider medication effects: Certain medications (stimulants, decongestants, bronchodilators) affect heart rate variability

When to Seek Medical Evaluation

Consult a physician if your elevated stress score accompanies:

• Chest pain, palpitations, or syncope during activity
• Persistent fatigue despite adequate rest
• Unexplained weight loss or fever
• Scores remaining elevated for more than 2-3 weeks without identifiable cause

Important Caveats

Sensor accuracy limitations 1: Wrist-based optical heart rate sensors can be affected by movement artifact, skin tone, tattoos, and device positioning. Ensure your watch fits snugly (one finger-width above wrist bone) during measurements.

Context matters: A high stress score during or immediately after intense exercise is expected and normal. Focus on your resting stress scores and recovery patterns rather than isolated readings.

Individual baseline variation: Your "normal" stress score range may differ significantly from population averages due to genetic factors, fitness level, and baseline autonomic tone 8.