Abstract: This study evaluates firefighter sleep, wellness, and operational readiness under different shift start times and duty schedules. It compares the 24/48 and 48/96 models and examines how delaying shift start times affects sleep offset, recovery, circadian alignment, and fatigue. Data was collected through wearable sleep trackers, daily logs, and baseline and follow-up questionnaires. Results show measurable improvements in rest, morning readiness, and wellness when shift timing is optimized. Findings were presented at Science to the Station, NERDSTOCK 2025.

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Study Overview: This project examines how shift start times influence firefighter sleep behavior, recovery, and overall wellness. The evaluation compares traditional 24/48 schedules with the increasingly adopted 48/96 model. The study incorporates wearable sleep tracking data, self-reported sleep logs, and questionnaire measures to assess sleep offset, sleep efficiency, circadian alignment, and fatigue. Findings highlight improvements in rest, reduced morning fatigue, and better home and family impact when shift timing is adjusted. The presentation provides practical insight for fire service leaders interested in evidence-informed scheduling and operational readiness.

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Dr. Joe Pennino
Email: pennino.joe@gmail.com

LinkedIn: https://www.linkedin.com/in/drjoepennino/

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Dr. Joel Billings
Program Chair, Embry-Riddle Aeronautical University
Email: Joel.billings@erau.edu

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Methodology
The Sleep Improved study used a mixed-methods approach to evaluate sleep behavior and wellness across firefighter duty schedules. Data collection included wearable sleep tracking devices, daily sleep logs, baseline and follow-up questionnaires, and observations related to alertness, sleep offset, sleep latency, nightly duration, and evening recovery. The project compared sleep outcomes under the 24/48 schedule and the 48/96 schedule, with specific attention to how delayed shift start times influence recovery, circadian alignment, and fatigue.

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Key Findings
The preliminary results of the Sleep Improved study show clear improvements in sleep and wellness when shift start times are adjusted. Firefighters experienced increases in sleep offset, better alignment with their natural circadian rhythm, and improved morning alertness. Sleep duration increased overall, and fatigue levels showed downward trends during the first half of each shift. Participants also reported less disruption at home and more consistent rest before reporting for duty. These outcomes reinforce the potential benefits of evidence-informed shift timing adjustments for operational readiness and overall firefighter well-being.