University of Oulu

I. Alikhani, K. Noponen, M. Tulppo, J. Peltonen, E. Lehtonen and T. Seppänen, "Heart Rate Variability and its Association with Second Ventilatory Threshold Estimation in Maximal Exercise Test," 2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Glasgow, Scotland, United Kingdom, 2022, pp. 139-142, doi: 10.1109/EMBC48229.2022.9871913

Heart rate variability and its association with second ventilatory threshold estimation in maximal exercise test

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Author: Alikhani, Iman1; Noponen, Kai1; Tulppo, Mikko2;
Organizations: 1Center for Machine Vision and Signal Analysis of the University of Oulu, Finland
2Research Unit of Biomedicine, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
3HULA – Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine, Helsinki, Finland
4Department of Sports and Exercise Medicine, Clinicum, University of Helsinki, Helsinki, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.4 MB)
Persistent link:
Language: English
Published: Institute of Electrical and Electronics Engineers, 2022
Publish Date: 2023-03-28


During incremental exercise, two ventilatory thresholds (VT1, VT2) can normally be identified from gas exchange and ventilatory measurements, such as oxygen uptake, carbon dioxide production and ventilation. In this paper, we attempt to estimate the VT2 using HRV indices derived from a wearable electrocardiogram during a maximal exercise test. The exercise test is conducted on a treadmill that raises its speed by 0.5 km/h every minute. We have 42 measured exercise tests from 24 healthy male volunteers. Three experts determined the VT2 in each exercise test independently and we used principal component subspace reconstruction of their determinations to compute a collective VT2 for our machine learning model. The results demonstrate that the VT2 can be estimated from HRV using the proposed method with a reasonable performance during a maximal exercise test. In 28 out of 42 exercise tests, the HRV-derived threshold (HRVT) is within a minute (one phase) of the collective expert’s determination.

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Series: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
ISSN: 2375-7477
ISSN-E: 2694-0604
ISSN-L: 2375-7477
ISBN: 978-1-7281-2782-8
ISBN Print: 978-1-7281-2783-5
Pages: 139 - 142
DOI: 10.1109/embc48229.2022.9871913
Host publication: 2022 44th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC)
Conference: Annual International Conference of the IEEE Engineering in Medicine & Biology Society
Type of Publication: A4 Article in conference proceedings
Field of Science: 217 Medical engineering
113 Computer and information sciences
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