Original Post: 06/25/2024

Shift schedule is inevitable when working in public safety. This concept is deemed as “part of the job” for many roles associated to being a first responder, such as fire and rescue. Within the world of firefighting, dialogue and discussions begin to develop: Which schedule is best? What is our schedule doing to us? Can we make the most out of the schedule we have? Although all these questions are valid to ask, where do we begin to acquire the data to make judgement calls? What do we reference to justify transition or even justify maintaining our status. With these questions building up more and more, investigators at the Texas A&M University – Commerce ROARHP Exercise Physiology Lab took on a task to bring a physiological way to answer the questions. Even then, the project being in its starting stages, has the potential to shed light toward possible solutions within the world of shift scheduling.

What is the Recovery Standard Project?

The Recovery Standard Project was founded (and named) by tactical researchers Hussien Jabai and Dr. Michael Oldham, in an effort to provide agencies and departments across the nation with tangible biometrics that analyze the physiological adaptations to shift schedules. This initiative began as a pilot program, observing the recovery patterns of fire fighters in Texas on a 24-hour on and 48-hour off schedule. With that said, this frequency of work is commonly interrupted by overtime shifts obtained by personnel (regardless of the reason why, it happens). Preliminary findings of the study were very insightful and expanded into a conversation with other agencies requesting a comparison with the 48-hour on and 96-hour off shift schedule. Due to internal university awards and grants, the investigators were able to assess a sample of 24/48 and 48/96 during a 3-month timeline. (Identity of departments remain confidential at this time). With time and awareness, the project expanded. An agency in Virginia reached out to the team in efforts to observe their current shift schedule, a modified Kelly schedule. With the growth and development of efforts by the research team, the project will continue to perform, produce, and thrive based on the awareness, support, and efforts of the agencies that drive wellness initiatives. With doing so, the project outlines the following purpose:

• Provide a platform to assist participating firefighters in observing data to help regulate their off-shift physical activity.
• Provide a means for participating firefighters to understand the impact that sleep, nutrition, job-tasks/workload, and physical activity has on the body.
• Provide a line of communication for personnel to engage in conversation with collaborating parties regarding fitness and nutrition.
• Provide insight on the impact that specific shift work has on recovery of participating firefighters.
• Assess the difference in recovery rates/patterns when comparing various shift schedules associated with public safety

What instrument or device is being used to monitor personnel?

Participants in this study utilized WHOOP® straps, which are wrist worn devices that monitor health metrics, such as sleep patterns, heart rate / resting heart rate, respiratory rate, blood oxygen, and skin temperature. Vital metrics we focused on were observing both HRV and daily (accumulated) strain.

3-Tier System to Research Development

The tactical research team always approach questions and projects as follows:

• Observe what is currently going on. (Observation) If you can measure it, you can manage it.
• Implement a change or two. (Intervention) Start with one change, monitor its effects. Then adjust as needed. Find the best fit/practice for the desired outcome.
• Integrate key professionals into roles that will support the longevity of the wellness initiative. (Integration)

All entities, when investigating potential issues or concerns, are recommended to follow this method – observation, intervention, integration.

What shift schedules have we observed?

• 24/48
• 48/96
• Modified Kelly

What data are we collecting?

The current study is collecting the following:

• HRV
• Resting HR
• Recovery Score
• Sleep Score

Internally and collaboratively, agencies are collecting various components associated with events, job descriptions, and other important variables.

What is heart rate variability (HRV)?

Heart rate variability, known as HRV, is the measured interval between heartbeats utilized as a marker of the capacity to regulate internal and external demands (Young, & Benton, 2018). A higher HRV is associated with better health (Young, & Benton, 2018), while a lower HRV has been associated with many negative health effects (shown below). The measured interval between beats is not always constant (Young, & Benton, 2018), therefore monitoring protocol should allow for a duration of time to develop a baseline for participants. Utilizing devices that monitor HRV is a noninvasive way of evaluating autonomic cardiac function (Harris, et al., 2014).

In a clinical setting, low HRV is associated with mortality in patients with:

• coronary artery disease
• chronic heart failure
• history of myocardial infarction

Low HRV associated with:

• hypertension
• end-stage renal disease
• diabetes

(de Geus, et al., 2019)

Reduction of HRV also associated with the following:

• diabetes
• cardiovascular disease
• inflammation
• obesity
• psychiatric disorders

(Young, & Benton, 2018)

How do you get involved as an agency?

Everything begins with initiative. If you have the initiative, the drive, the aspirations to facilitate change within your agency, then you are past the first of many obstacles. With that, simply reach out to professionals within the academic and research space. Find researchers with like-minded ambitions and areas of interest. Everything can flourish from a simple conversation.

References

de Geus, E., Gianaros, P. J., Brindle, R. C., Jennings, J. R., & Berntson, G. G. (2019). Should heart rate variability be “corrected” for heart rate? Biological, quantitative, and interpretive considerations. Psychophysiology, 56(2), e13287. https://doi.org/10.1111/psyp.13287

Harris, P. R., Stein, P. K., Fung, G. L., & Drew, B. J. (2014). Heart rate variability measured early in patients with evolving acute coronary syndrome and 1-year outcomes of rehospitalization and mortality. Vascular health and risk management, 10, 451–464. https://doi.org/10.2147/VHRM.S57524 

Young, H. A., & Benton, D. (2018). Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?. Behavioural pharmacology, 29(2 and 3-Spec Issue), 140–151. https://doi.org/10.1097/FBP.0000000000000383