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The impact of sleep restriction while performing simulated physical firefighting work on cortisol and heart rate responses

journal contribution
posted on 06.12.2017, 00:00 by A Wolkow, B Aisbett, J Reynolds, Sally Ferguson, L Main
Purpose: Physical work and sleep restriction are two stressors faced by firefighters, yet the combined impact these demands have on firefighters’ acute stress responses is poorly understood. The purpose of the present study was to assess the effect firefighting work and sleep restriction have on firefighters’ acute cortisol and heart rate (HR) responses during a simulated 3-day and 2-night fire-ground deployment. Methods: Firefighters completed multiple days of simulated physical work separated by either an 8-h (control condition; n = 18) or 4-h sleep opportunity (sleep restriction condition; n = 17). Salivary cortisol was sampled every 2 h, and HR was measured continuously each day. Results: On day 2 and day 3 of the deployment, the sleep restriction condition exhibited a significantly higher daily area under the curve cortisol level and an elevated cortisol profile in the afternoon and evening when compared with the control condition. Firefighters’ HR decreased across the simulation, but there were no significant differences found between conditions. Conclusion: Findings highlight the protective role an 8-h sleep opportunity between shifts of firefighting work has on preserving normal cortisol levels when compared to a 4-h sleep opportunity which resulted in elevated afternoon and evening cortisol. Given the adverse health outcomes associated with chronically high cortisol, especially later in the day, future research should examine how prolonged expo- sure to firefighting work (including restricted sleep) affects firefighters’ cortisol levels long term. Furthermore, monitoring cortisol levels post-deployment will determine the minimum recovery time firefighters need to safely return to the fire-ground.

Funding

Category 4 - CRC Research Income

History

Issue

2015

Start Page

1

End Page

15

Number of Pages

15

eISSN

1432-1246

ISSN

0340-0131

Location

Germany

Publisher

Springer

Language

en-aus

Peer Reviewed

Yes

Open Access

No

External Author Affiliations

Bushfire CRC (Australia); Deakin University; School of Human, Health and Social Sciences (2013- ); TBA Research Institute;

Era Eligible

Yes

Journal

International archives of occupational and environmental health.

Exports

CQUniversity

Exports