Lucrezia Zuccarelli1,2, Simone Porcelli1, Letizia Rasica1,3, Mauro Marzorati1, Bruno Grassi1,2. 1. Institute of Molecular Bioimaging and Physiology, National Research Council, Segrate, ITALY. 2. Department of Medicine, University of Udine, Udine, ITALY. 3. Department of Biomedical Science for Health, University of Milan, Milan, ITALY.
Abstract
PURPOSE: Aerobic exercise prescription is often based on a linear relationship between pulmonary oxygen consumption (V˙O2) and heart rate (HR). The aim of the present study was to test the hypothesis that during constant work rate (CWR) exercises at different intensities, the slow component of HR kinetics occurs at lower work rate and is more pronounced that the slow component of V˙O2 kinetics. METHODS: Seventeen male (age, 27 ± 4 yr) subjects performed on a cycle ergometer an incremental exercise to voluntary exhaustion and several CWR exercises: 1) moderate CWR exercises, below gas exchange threshold (GET); 2) heavy CWR exercise, at 45% of the difference between GET and V˙O2 peak (Δ); 3) severe CWR exercise, at 95% of Δ; 4) "HRCLAMPED" exercise in which work rate was continuously adjusted to maintain a constant HR, slightly higher than that determined at GET. Breath-by-breath V˙O2, HR, and other variables were determined. RESULTS: In moderate CWR exercises, no slow component of V˙O2 kinetics was observed, whereas a slow component with a relative amplitude (with respect to the total response) of 24.8 ± 11.0% was observed for HR kinetics. During heavy CWR exercise, the relative amplitude of the HR slow component was more pronounced than that for V˙O2 (31.6 ± 11.2% and 23.3 ± 9.0%, respectively). During HRCLAMPED, the decrease in work rate (~14%) needed to maintain a constant HR was associated with a decreased V˙O2 (~10%). CONCLUSIONS: The HR slow component occurred at a lower work rate and was more pronounced than the V˙O2 slow component. Exercise prescriptions at specific HR values, when carried out for periods longer than a few minutes, could lead to premature fatigue.
PURPOSE: Aerobic exercise prescription is often based on a linear relationship between pulmonary oxygen consumption (V˙O2) and heart rate (HR). The aim of the present study was to test the hypothesis that during constant work rate (CWR) exercises at different intensities, the slow component of HR kinetics occurs at lower work rate and is more pronounced that the slow component of V˙O2 kinetics. METHODS: Seventeen male (age, 27 ± 4 yr) subjects performed on a cycle ergometer an incremental exercise to voluntary exhaustion and several CWR exercises: 1) moderate CWR exercises, below gas exchange threshold (GET); 2) heavy CWR exercise, at 45% of the difference between GET and V˙O2 peak (Δ); 3) severe CWR exercise, at 95% of Δ; 4) "HRCLAMPED" exercise in which work rate was continuously adjusted to maintain a constant HR, slightly higher than that determined at GET. Breath-by-breath V˙O2, HR, and other variables were determined. RESULTS: In moderate CWR exercises, no slow component of V˙O2 kinetics was observed, whereas a slow component with a relative amplitude (with respect to the total response) of 24.8 ± 11.0% was observed for HR kinetics. During heavy CWR exercise, the relative amplitude of the HR slow component was more pronounced than that for V˙O2 (31.6 ± 11.2% and 23.3 ± 9.0%, respectively). During HRCLAMPED, the decrease in work rate (~14%) needed to maintain a constant HR was associated with a decreased V˙O2 (~10%). CONCLUSIONS: The HR slow component occurred at a lower work rate and was more pronounced than the V˙O2 slow component. Exercise prescriptions at specific HR values, when carried out for periods longer than a few minutes, could lead to premature fatigue.
Authors: Jie Kang; Nicholas A Ratamess; Avery D Faigenbaum; Jill A Bush; Christopher Roser; Devyn Montemarano; Hannah Mercado; Morgan Choma; Christian Mendez; Matthew Pollock Journal: Int J Exerc Sci Date: 2020-12-01
Authors: Damir Zubac; Vladimir Ivančev; Vincent Martin; Antonio Dello Iacono; Cécil J W Meulenberg; Adam C McDonnell Journal: PeerJ Date: 2022-04-13 Impact factor: 3.061
Authors: Carlo Ferri Marini; Ario Federici; James S Skinner; Giovanni Piccoli; Vilberto Stocchi; Luca Zoffoli; Luca Correale; Stefano Dell'Anna; Carlo Alberto Naldini; Matteo Vandoni; Francesco Lucertini Journal: PeerJ Date: 2022-04-25 Impact factor: 3.061
Authors: Ronen Bar-Yoseph; Shlomit Radom-Aizik; Nicholas Coronato; Nazanin Moradinasab; Thomas J Barstow; Annamarie Stehli; Don Brown; Dan M Cooper Journal: Physiol Rep Date: 2022-08
Authors: Diego Jaén-Carrillo; Luis E Roche-Seruendo; Antonio Cartón-Llorente; Rodrigo Ramírez-Campillo; Felipe García-Pinillos Journal: Sensors (Basel) Date: 2020-11-13 Impact factor: 3.576