What type of Stress is StressWatch measuring? What is the basic principle of its measurement?

StressWatch measures physical stress based on heart rate data.

What is physical stress?

Physical stress is used to measure whether the body is in a state of stress and whether the autonomic nervous system is in a state of tension.

When we are under excessive psychological stress, tiredness, recovery period, illness, medication/alcohol/caffeine intake, etc., the body may be in a state of greater stress.

If we stay in a state of greater physical stress for a long time, it may cause physiological effects, such as decreased immunity, increased risk of cardiovascular disease, digestive system disorders, endocrine disorders, chronic pain, etc., as well as psychological effects, such as anxiety, depression, emotional fluctuations, sleep disorders, etc.

What is the relationship between physical stress and psychological stress?

Physical stress and psychological stress are positively correlated in many cases. When individuals experience acute or chronic psychological stress, the degree of heart rate variability and frequency of heartbeats may be affected and can be captured and interpreted by StressWatch. Therefore, the assessment of physical stress is somewhat indicative of psychological stress.

However, physical stress and psychological stress are not necessarily positively correlated in some cases. For example, when we drink alcohol or coffee, our body is under stress due to the stimulation, causing HRV to decrease, but our psychological stress may be relatively low.

Physical stress is relatively objective, while psychological stress has more subjective factors.

What can physical stress provide as a reference?

Long-term physical stress may have negative effects on mental health, such as increased risk of anxiety and depression. At the same time, psychological stress can also affect the body, such as chronic psychological stress may lead to physiological stress responses, such as decreased immune function, increased cardiovascular health risks, etc.

Therefore, by continuously tracking and understanding physical stress through StressWatch, we can:

  • Provide a reference for psychological stress: Understand the sources of physical stress and assess the impact of psychological stress on them according to individual situations, and better manage psychological stress;
  • Identify physical stress in advance: By monitoring HRV and resting heart rate, we can identify the presence and degree of physical stress in advance. Low HRV and high resting heart rate may indicate that the body is under greater stress, which may have potential negative effects on health;
  • Guide physical stress management: The monitoring results of HRV and resting heart rate can be used as a reference for physical stress management. By adjusting lifestyle, coping strategies, and psychological health management methods, we can improve the levels of HRV and resting heart rate, thereby helping to reduce physical stress levels;
  • Prevent health risks: Long-term physical stress may have negative effects on health, such as cardiovascular disease, immune system disorders, etc. By paying attention to HRV and resting heart rate, we can prevent potential health risks in advance and take active intervention measures.

Paying attention to the physical stress shown by HRV and resting heart rate can help detect the state of high physical stress early and take timely intervention measures to avoid potential health risks. By monitoring and managing physical stress, we can better manage overall physical and mental stress, reduce anxiety, and establish good habits.

What is the basic principle of measuring physical stress by StressWatch? What do the levels represent?

Heartbeat is controlled by the autonomic nervous system, which includes the sympathetic nervous system and parasympathetic nervous system: The sympathetic nervous system is responsible for stimulating the body to respond or escape (which can cause HRV to decrease and resting heart rate to increase) when we need to take action, while the parasympathetic nervous system mainly is responsible for the body's rest function (which can cause HRV to increase and resting heart rate to decrease).

When we face stress and the body produces a stress response, there will be a noticeable change in heart rate, especially in HRV (heart rate variability) and resting heart rate.

StressWatch evaluates an individual's body pressure level by analyzing HRV (heart rate variability) and resting heart rate data, establishing a data baseline based on each person's historical data and providing personalized analysis.

StressWatch divides comprehensive pressure into four levels:

  • 🟢 Excellent state: Compared to an individual's historical data, the person has a high level of HRV and a low level of resting heart rate, indicating a very low level of body pressure.
  • 🔵 Normal state: Compared to an individual's historical data, the person has a normal level of HRV and a normal level of resting heart rate, indicating a manageable level of body pressure.
  • 🟡 Attention needed: Compared to an individual's historical data, the person has a low level of HRV or a high level of resting heart rate, indicating an elevated level of body pressure that requires attention and corresponding adjustments, such as rest, relaxation, and lifestyle adjustments.
  • 🔴 Pressure overload: Compared to an individual's historical data, the person has a significant decrease in HRV and a significant increase in resting heart rate, indicating a significantly increased level of body pressure, which may pose a risk of body pressure overload.

The four levels can help us intuitively understand the trend changes in body pressure.

References

  1. Joachim Taelman, S. Vandeput, A. Spaepen & S. Van Huffel (2009), Influence of Mental Stress on Heart Rate and Heart Rate Variability, IFMBE,volume 22
  2. R. Castaldo, P. Melillo, U. Bracale, M. Caserta, M. Triassi, L. Pecchi, Acute mental stress assessment via short term HRV analysis in healthy adults: A systematic review with meta-analysis, Biomedical Signal Processing and Control 18
  3. Shaffer, F., & Ginsberg, J. P. (2017). An overview of heart rate variability metrics and norms. Frontiers in public health, 258.
  4. Hye-Geum Kim, Eun-Jin Cheon, Dai-Seg Bai, Young Hwan Lee & Bon-Hoon Koo (2018). Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Psychiatry Investig. 15(3): 235–245.
  5. J. P. A. Delaney and D. A. Brodie (2000). Effects of Short-Term Psychological Stress on the Time and Frequency Domains of Heart-Rate Variability, Sage Journals, Volume 91 Issue 2
  6. Mimma Nardelli; Gaetano Valenza; Alberto Greco; Antonio Lanata; Enzo Pasquale Scilingo (2015). Recognizing Emotions Induced by Affective Sounds through Heart Rate Variability, IEEE Transactions on Affective Computing, Volume: 6, Issue: 4, 385 - 394