Understanding Acute Stress: What Science Tells Us About the Body’s Response

Understanding Acute Stress: What Science Tells Us About the Body’s Response

Understanding Acute Stress: What Science Tells Us About the Body’s Response

Stress is a universal experience—whether it's triggered by work deadlines, personal challenges, or unexpected life events. While many stress management techniques promise relief, not all are grounded in science. That’s why research like Ernst, Scherpf, Pannasch, Helmert, Malberg, and Schmidt (2023) is so valuable. It helps us understand how the body responds to acute mental stress and which physiological markers are most reliable for assessing that response.

Acute stress refers to the body's immediate reaction to a perceived threat or challenge. It activates the "fight-or-flight" response, triggering a cascade of physiological changes such as increased heart rate, elevated cortisol levels, and heightened alertness. Unlike chronic stress, which persists over time, acute stress is short-term and typically resolves once the stressor is removed. Understanding this response is key to developing effective, evidence-based stress management strategies.

In this post, we’ll explore the study’s methodology and findings, and discuss how they can inform practical, evidence-based approaches to managing stress.

The Study

The study, titled Assessment of the human response to acute mental stress – An overview and a multimodal study, aimed to identify the most effective physiological indicators of acute mental stress. Ernst et al. (2023) combined a comprehensive literature overview with a controlled experimental study to evaluate how the human body reacts to stress in real time.

Methodology

Ernst et al. (2023) recruited 65 healthy participants and exposed them to acute mental stress using the Mannheim Multicomponent Stress Test (MMST)—a validated method that combines cognitive, emotional, and social stressors.

They collected data from multiple sources:

  • Self-assessment tools: Likert scales and the Self-Assessment Manikin (SAM) to gauge subjective stress.
  • Biochemical markers: Salivary cortisol and α-amylase levels.
  • Physiological signals: Over 60 bio signal-derived vital signs, including heart rate variability, QT interval variability, skin conductance, and respiratory patterns.

To analyse the data, Ernst et al. (2023) used statistical testing and a self-optimizing logistic regression model to determine which physiological markers were most predictive of acute stress.

Key Findings

The study revealed several important insights:

  • Successful Stress Induction: Self-assessments confirmed that participants experienced stress during the MMST.
  • Biochemical Response: Cortisol levels increased (effect size = 0.55), while α-amylase levels decreased (effect size = -0.78), indicating activation of both the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system.
  • Top Physiological Indicators: The most significant bio signal markers included:
    • QT variability index
    • Left ventricular work index
    • Earlobe pulse arrival time
    • Skin conductance level and response
    • Breath rate and breath rate variability

The logistic regression model achieved a strong performance with an F1 score of 0.82, suggesting high accuracy in identifying stress responses based on these markers.

Acute Stress and Stress Management

Understanding how the body reacts to acute stress is crucial for developing effective stress management strategies. This study reinforces that stress is not just a mental or emotional experience—it has measurable physiological effects.

By identifying reliable biomarkers, researchers and clinicians can better evaluate the effectiveness of stress-reduction techniques such as:

  • Mindfulness and breathwork, which influence respiratory rate and heart rate variability.
  • Biofeedback training, which targets skin conductance and cardiovascular responses.
  • Cognitive-behavioural strategies, which may indirectly affect physiological stress markers by altering perception and emotional regulation.

Practical Implications

For individuals seeking to manage stress more effectively, this study highlights the importance of:

  • Choosing evidence-based techniques that target known physiological stress responses.
  • Monitoring progress using measurable indicators (e.g., heart rate variability apps or wearable devices).
  • Avoiding pseudoscientific methods that lack empirical support.

For researchers and clinicians, the findings offer a roadmap for designing more accurate stress assessments and interventions.

Conclusion

Ernst et al. (2023) provides a valuable contribution to our understanding of acute mental stress. By identifying the most responsive physiological markers, it lays the groundwork for more precise and personalized stress management strategies.

As we continue to explore the science of stress, studies like this remind us that effective relief starts with understanding how our bodies truly respond.

Disclaimer: This blog post is for informational purposes only and does not constitute medical advice. Always seek the guidance of a qualified healthcare provider with any questions you may have regarding a medical condition or treatment.

Reference
Ernst, H., Scherpf, M., Pannasch, S., Helmert, J. R., Malberg, H., & Schmidt, M. (2023). Assessment of the human response to acute mental stress–An overview and a multimodal study. PLoS ONE, 18(11), e0294069. https://doi.org/10.1371/journal.pone.0294069

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