Multimodal approach towards understanding the changes in the autonomic nervous system induced by an ultramarathon

ABSTRACT

Purpose: Running an ultramarathon can be considered as a multifaceted, intense stressor inducing changes within the autonomic nervous system (ANS). The aim of this study was to examine changes within and across ANS modalities in response to an ultramarathon.

Methods: Thirteen runners (44.3 ± 5.9 years) completed a 65 km run. Electrodermal activity (EDA), heart rate (HR), and skin temperature measured at wrist (Temp), were recorded before and after running. Three-minute intervals were analysed. Mean values were compared by t-tests for dependent samples. Joint principal component analysis-canonical correlation analysis (PCA-CCA) and multiset CCA techniques were employed to measure the interactions between either any two or among all modalities.

Results: HR (p < 0.01) and EDA (p < 0.01) increased, while Temp decreased (p < 0.01). PCA-CCA revealed one significant component (p < 0.05) for each modality pair in pre and post measures. Component strength increased from pre (mean = 0.73) to post (mean = 0.92) test. Multiset CCA supported the assumption of increasing strength of correlations across modalities.

Conclusion: Ultramarathon, an intense physical stressor, increases correlations across modalities pointing towards a reorganization of central ANS control to restore dynamic balance after physical load. This characterization of ANS-states might offer new avenues for training control.

KEYWORDS:

• Autonomic network
• canonical correlation analysis
• heart rate
• electrodermal activity
• temperature

Acknowledgments

We thank Dr. Rasmus Jakobsmeyer, Tanja I. Janssen, Leoni Cramer, Roman Gaidai and Jennifer Ahmann for support during data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

TH and PJS were supported by a Research Grant from the German Research Foundation (DFG), contract SCHR 1384/3-2. This study was also supported by a grant of the Westfalen foundation (Stiftung Westfalen).