Core Viewpoint - The article discusses the inaccuracies of stress monitoring by smartwatches and apps, emphasizing that the data they provide may not accurately reflect users' psychological stress levels [6][55]. Group 1: User Experiences - Many users have reported discrepancies between their perceived stress levels and the readings from their smartwatches, indicating that the devices may not be reliable [9][54]. - Instances include users feeling relaxed but receiving notifications of high stress, suggesting that the devices may misinterpret physiological signals [13][46]. Group 2: Measurement Methodology - Smartwatches typically measure stress through heart rate variability (HRV), which reflects the variation in time between heartbeats rather than the heart rate itself [19][35]. - A healthy heart rate shows variability, while a low HRV indicates stress, but this does not differentiate between psychological and physiological stressors [30][47]. Group 3: Physiological vs. Psychological Stress - Various factors, such as caffeine intake, exercise, and emotional excitement, can lower HRV, leading to misleading stress readings from smartwatches [39][45]. - The article highlights that physiological stress can trigger the same responses as psychological stress, complicating the interpretation of HRV data [38][46]. Group 4: Limitations of Wearable Technology - The article points out that wearable devices often lack the capability to provide a nuanced understanding of stress, as they primarily focus on HRV without considering other factors [58][60]. - Clinical assessments of psychological stress involve a multi-dimensional evaluation, which smartwatches do not provide [57][75]. Group 5: User Misunderstanding and Marketing - There is a concern that marketing for stress-monitoring apps may mislead users into believing that these devices can accurately measure psychological stress [63][64]. - While these apps can provide some insights into overall physiological load, they should not be relied upon for precise psychological assessments [70][74].

Core Viewpoint - The article discusses the inaccuracies of stress measurement by smartwatches and apps, emphasizing that the heart rate variability (HRV) used to gauge stress does not solely reflect psychological pressure but also includes various physiological factors [19][32][52]. Group 1: Measurement Methodology - Smartwatches typically measure stress through heart rate variability (HRV), which indicates the variation in time between heartbeats [19][30]. - A healthy heart rate shows variability, while a consistent rhythm indicates lower HRV, suggesting higher stress levels [20][28]. - The autonomic nervous system, comprising the sympathetic (SNS) and parasympathetic (PNS) systems, regulates heart rate and can influence HRV based on various stimuli [22][25]. Group 2: Factors Affecting HRV - Both psychological and physiological stressors can lower HRV, including caffeine intake, smoking, intense exercise, and emotional excitement [34][35][42]. - The smartwatch cannot differentiate between types of stress, leading to potential misinterpretations of the user's actual stress state [44][52]. Group 3: Research Findings - A study involving 781 students found a significant mismatch between smartwatch-measured stress and self-reported stress levels, indicating that wearable device data may not accurately reflect user experiences [46][49]. - The research concluded that wearable device data and self-reported data might represent different concepts, highlighting the limitations of current stress measurement technologies [50][51]. Group 4: User Perception and Misunderstanding - Many users may misinterpret the capabilities of stress-monitoring apps, believing they can accurately assess psychological pressure when they primarily reflect physiological load [56][62]. - The article suggests that while these apps can provide some value, they should not be relied upon for precise psychological assessments [59][65].