AUTHOR=Papini Gabriele B. , Bonomi Alberto G. , Sartor Francesco 

TITLE=Proof-of-concept model for instantaneous heart rate-drift correction during low and high exercise exertion

JOURNAL=Frontiers in Physiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1358785

DOI=10.3389/fphys.2024.1358785

ISSN=1664-042X

ABSTRACT=<p><bold>Introduction:</bold> This study aimed to model below and above anaerobic threshold exercise-induced heart rate (HR) drift, so that the corrected HR could better represent <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>O</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:math></inline-formula> kinetics during and after the exercise itself.</p><p><bold>Methods:</bold> Fifteen healthy subjects (age: 28 ± 5 years; <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>O</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mi>M</mml:mi><mml:mi>a</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>: 50 ± 8 mL/kg/min; 5 females) underwent a maximal and a 30-min submaximal (80% of the anaerobic threshold) running exercises. A five-stage computational (i.e., delay block, new training impulse-calculation block, Sigmoid correction block, increase block, and decrease block) model was built to account for instantaneous HR, fitness, and age and to onset, increase, and decrease according to the exercise intensity and duration.</p><p><bold>Results:</bold> The area under the curve (AUC) of the hysteresis function, which described the differences in the maximal and submaximal exercise-induced <inline-formula id="inf3"><mml:math id="m3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>O</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:math></inline-formula> and HR kinetics, was significantly reduced for both maximal (26%) and submaximal (77%) exercises and consequent recoveries.</p><p><bold>Discussion:</bold> In conclusion, this model allowed HR drift instantaneous correction, which could be exploited in the future for more accurate <inline-formula id="inf4"><mml:math id="m4" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mover accent="true"><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mo>̇</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>O</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:msub></mml:math></inline-formula> estimations.</p>