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A mathematical model for predicting cardiovascular responses at rest and during exercise in demanding environmental conditions

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journal contribution
posted on 05.08.2022, 15:15 authored by Alex LloydAlex Lloyd, Dusan Fiala, Christian Heyde, George HavenithGeorge Havenith

The present research describes the development and validation of a cardiovascular sub-model (CVR Model) for use in conjunction with advanced thermophysiological models, where usually only a total cardiac output is estimated. The CVR Model detailed herein estimates cardio-dynamic parameters (changes in cardiac output, stroke volume, heart rate), regional blood flow, and muscle oxygen extraction, in response to rest and physical workloads, across a range of ages and aerobic fitness levels, as well as during exposure to heat, dehydration, and altitude. The model development strategy was to first establish basic resting and exercise predictions for cardiodynamic parameters in an 'ideal' environment (cool, sea level, hydrated person). This basic model was then advanced for increasing levels of altitude, heat strain and dehydration, using meta-analysis and reaggregation of published data. Using the estimated altitude- and heat-induced changes in maximum oxygen extraction and maximum cardiac output, the decline in maximum oxygen consumption at high-altitude and in the heat was also modelled. A validation of predicted cardiovascular strain using heart rate was conducted using a dataset of 101 heterogeneous individuals (1371 data points) during rest and exercise in the heat and at altitude, demonstrating that the CVR model performs well (R2 = 0.82-0.84) in predicting cardiovascular strain, particularly at a group mean level (R2 = 0.97). The development of the CVR Model is aimed at providing the FPC Model and other complex thermophysiological models with improved estimations of cardiac strain and exercise tolerance, across a range of individuals during acute exposure to environmental stressors.

Funding

adidas Sport Science Team, Germany

Environmental Ergonomics Research Centre, Loughborough University, UK

History

School

  • Design and Creative Arts

Department

  • Design

Published in

Journal of Applied Physiology

Volume

133

Issue

2

Pages

247 - 261

Publisher

American Physiological Society

Version

VoR (Version of Record)

Rights holder

© The Authors

Publisher statement

This is an Open Access Article. It is published by the American Physiological Society under the Creative Commons Attribution 4.0 International Licence (CC BY). Full details of this licence are available at: https://creativecommons.org/licenses/by/4.0/

Acceptance date

27/05/2022

Publication date

2022-06-02

Copyright date

2022

ISSN

8750-7587

eISSN

1522-1601

Language

en

Depositor

Dr Alex Lloyd. Deposit date: 2 June 2022