@article{ref1,
title="Contribution of the autonomic nervous system to recovery in firefighters",
journal="Journal of athletic training",
year="2020",
author="Ebersole, Kyle T. and Cornell, David J. and Flees, Robert J. and Shemelya, Corey M. and Noel, Sabrina E.",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="CONTEXT: Sudden cardiac deaths (SCDs) have accounted for nearly half of the line-of-duty deaths among US firefighters over the past 10 years. In 2018, 33% of all SCDs occurred after the end of a fire service call. Researchers have suggested that an imbalance in autonomic nervous system (ANS) regulation of heart rate postcall may interfere with recovery in firefighters.   OBJECTIVE: To use heart-rate recovery (HRR) and heart-rate variability (HRV), 2 noninvasive markers of ANS function, to examine the ANS recovery profiles of firefighters.   DESIGN: Cross-sectional study.   SETTING: Firehouse and research laboratory.   PATIENTS OR OTHER PARTICIPANTS: Thirty-seven male career active-duty firefighters (age = 39 ± 9 years, height = 178.8 ± 5.4 cm, mass = 87.9 ± 11.2 kg).   MAIN OUTCOME MEASURE(S): Percentage of maximal HR (%MHR) and HRV (natural log of the square root of the mean sum of the squared differences [lnRMSSD]) were collected after both submaximal and maximal exercise protocols during a 10-minute seated recovery. The HRR profiles were examined by calculating the asymptote, amplitude, and decay parameters of the monoexponential HRR curve for each participant.   RESULTS: Differences in HRR parameters after 10 minutes of seated recovery were identified after submaximal versus maximal exercise (P <.001). In addition, although ANS was more suppressed after maximal exercise, HRV indicated incomplete recovery, and regardless of the test, recovery %MHR and lnRMSSD values did not return to pretest %MHR and lnRMSSD values.   CONCLUSIONS: Our results suggest that the ANS contributions to recovery in active-duty firefighters are exercise-intensity specific, and this is likely an important factor when establishing best-practice recovery guidelines.<p /> <p>Language: en</p>",
language="en",
issn="1062-6050",
doi="10.4085/1062-6050-0426.19",
url="http://dx.doi.org/10.4085/1062-6050-0426.19"
}