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Personal Sustainability Index (PSI)

In today’s turbulent world, dealing with constant and ever-changing stressors is the norm. We know that chronic stressors cumulatively over time harm our physical and mental health and well-being. Ongoing stress impairs the immune system, cognitive functioning, engagement at work, and makes us more prone to burnout.

There are four types of experiences that activate and exaggerate stress:
(a) the degree to which an activity is important to a person;
(b) the degree of uncertainty the person is experiencing;
(c) the degree to which others are watching or evaluating; and
(d) the anticipation of any of these experiences.

It has been difficult to study the cumulative effects of everyday stressors and how to prevent them without a tool for measuring them. The new Personal Sustainability Index (PSI) is just the tool we need. The PSI was described and validated in a 2021 article by Boyatzis et al in Consulting Psychology Journal: Practice and Researchtitled “Thrive and Survive: Assessing Personal Sustainability.”

The PSI is unique in that it tracks not only the frequency and variety of everyday stress events but also “renewal” events, such as walking in nature, playing with a child, or meditating, that help to counteract stress events. The article’s authors explain that reducing stress only helps us to survive, while increasing renewal instead helps us to thrive, and that the PSI is a critical tool for helping us get there.

The Stress Response

Boyatzis et al provide practical definitions of both stress and renewal. Stress activates the sympathetic nervous system (SNS), while renewal activates the parasympathetic nervous system (PNS). The SNS is a network of nerves important in the “fight-or-flight” response and is more active when a person is stressed or in danger. The PNS, associated with hormones like oxytocin and vasopressin, is the brake that shuts down the stress response.

Because we are so accustomed nowadays to low-level stressors, such chronic stress can fly under the radar. Boyatzis et al describe the problem: “Adapting to life can enable us to adjust to dangerous or dysfunctional levels of stress. The ordinariness of many episodes may deceive us into tolerating stress and not acknowledging or even noticing the strain from the cumulative impact.

The Importance of Renewal

The authors summarize the current theories on the need for a balance of stress events and renewal events: “…the degree of renewal (parasympathetic nervous system) needed is determined by the degree of stress (sympathetic nervous system) activated in the person during the recent past. The renewal experiences, if sufficient in arousal, can help to return the body to its prestress levels. The result is that the person has resources and energy in relationships, work, and life to feel more engaged, excited, and satisfied.

The PSI focuses on the cumulative impact of everyday stressors and measures the events that not just reduce stress but that activate the PNS to shut it down. It inventories 16 renewal and 17 stressful everyday events, which were gleaned from the psychological and medical literature on chronic stress. In the words of Boyatzis et al, “Renewal is not assessed as low stress but as actual experiences that invoke the PNS.

By measuring not just everyday stressors but also renewal events, the PSI provides an important tool for better understanding and managing chronic stress. It is unique in measuring both the amount/frequency and variety of stress and renewal events. This could be important, for example, because a person could form a difficult-to-change habit of reacting to all stressors in the same way, when a wide variety of renewal activities would build greater resources and resilience.

Frequency is determined by subtracting the total number of stress events from the total number of renewal events. Variety is determined by subtracting the total number of types of stress events from the total number of types of renewal events.


The PSI is an innovative tool for measuring everyday stress and renewal events. It helps us appreciate how low-grade stressors contribute to chronic stress and how renewal events can build resources and resilience. The PSI can be an informative tool for measuring how well a Coaching client is managing stress. It could also support the optimizing of stress management and improving the Coaching experience.

Takeaways for Coaches

Using the PSI directly or being inspired by its principles, Coaches can:

  1. Develop a list of renewal events (e.g., coaching, volunteering, showing compassion, exercise, nature, yoga, breathing, reflection, meditation, prayer, play, laughter, enjoyable meal) building on those inventoried in the PSI.
  2. Brainstorm on renewal activities with clients to counter their stress.
  3. Suggest that clients do a renewal activity just before or at the beginning of a coaching session to help them engage more in the growth process.
  4. Incorporate renewal activities into the coaching session to help clients integrate the skills learned.
  5. Encourage clients to track and manage their everyday stress and renewal activities.
  6. Help clients understand the importance of renewal activities not only for themselves but also for others at their organization.